The effects of crop residues on seedling disease of sugar beets caused by Aphanomyces cochlioides
drechs
by Stuart D Lyda
A THESIS Submitted to the Graduate Faculty in partial fulfillment of the requirements for the degree
of Master of Science in Botany
Montana State University
© Copyright by Stuart D Lyda (1958)
Abstract:
A study was made on the nature of the influence of residues of preceding crops on the fungus-induced
root rot of sugar beets caused by Aphanomyces cochlioides Drechs.
Six mature crop residues were incorporated into sterilized and non-sterilized soils that were planted to
sugar beets and inoculated with A. cochlioides. The incorporation of residues did not appear to
influence the intensity of disease in the sterilized soil. In the non-sterilized soil a reduction of disease of
varying degree was obtained for nearly every residue. Wheat-amended soil produced the greatest
reduction in diseased seedlings,” alfalfa, bean and corn were intermediate in their effect, and beet and
potato had the least apparent effect in reducing the amount of disease.
Nitrogen and phosphorus analyses were made of the various residues and each residue was adjusted to
the same level by the addition of NH4NO3 and P2O5. The addition of nitrogen alone increased the
growth of the plants in the sterilized soil, but did not produce noticeable effects on the growth of the
plants in the non-sterilized soil. There was a high ' incidence of disease in both sterilized and
non-sterilized soils when the nitrogen levels were adjusted. There was a low percentage of diseased
seedlings in the sterilized pots when both nitrogen and phosphorus levels were adjusted; however, in
non-sterilized soils amended with the same minerals the intensity of disease was high.
Soil-isolations were made with a modified Chester sampling tube. Fusaria spp. were the most
commonly isolated fungi. Ten different fungi were inoculated with A. cochlioides in sterilized and
non-sterilized soil • planted with sugar beets. Intensity of disease in the sterilized soil ranged from 93 to
100% and in non-sterilized soil from 22: to 55% THE EFFECTS OF CROP .RESIDUES ON SEEDLING
DISEASE OF SUGAR BEETS CAUSED BY
APHANOMYCES _
COCHLIOIDES
DRECES.
____
.
"by
STUART D« LYDA
A THESIS
• S u bm itted t o th e G raduate F a c u lty
in
'
;
p a r t i a l f u l f i l l m e n t o f th e re q u ire m e n ts
I
f o r th e d eg ree o f
M aster o f S cien ce i n B otany
at
Montana S ta te C o lleg e
A pproved;
Head, M ajor D epartm ent
Chairm an, E x am n in g Committee
B ozem an,' Mbntana
June 1.958
/4
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2
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ACKNOWLEDGMENT
G r a te f u l acknowledgment is made t o D r. M. M. A fa n a s ie v , D r. H. S.
Mac W ithey, D r. I . K. M ills , and D r. E . L. Sharp f o r t h e i r s u g g e stio n s
d u rin g th e s tu d y and f o r t h e i r a s s is ta n c e in p r e p a r a tio n o f th e m a n u sc rip t.
The a s s is ta n c e o f o th e r s t a f f members o f th e D epartm ent o f B otany and
B a c te rio lo g y , Montana S ta te C o lle g e , i s a ls o g r e a t l y a p p r e c ia te d .
T his work was su p p o rte d in p a r t b y fu n d s from R e g io n a l R esearch P r o j ­
e c t W-3 8 . N ature o f th e In flu e n c e o f Crop R esid u es on Fungus-Induced Root
D is e a s e . S u b -P ro je c t from M ontana, N ature o f th e In flu e n c e o f Crop R esid u es
on F ungus-Induced Root D isea se o f Sugar B ee ts Caused b y Aphanomyces c o c h ii o id e s D re c h s.
1-3 TABUE OF COMTEMTS
ACKNOWUEDGMEHT
2
ABSTRACT
k
INTRODUCTION '
5
REVIEW OF LITERATURE
7
MATERIALS AND METHODS
l4
RESULTS
R esidue E xperim ents
N itro g e n and R esidue
22
T est
32
N itro g e n , Phosphorus and R esidue T e s t
36
S o i l M ic ro flo ra I s o l a t i o n s and A n t i b i o t i c T e st
4l
R esidue Ash T e s t
45
DISCUSSION
48
SUMMARY
55
LITERATURE CITED
57
-4 -
ABSIRACT
A s tu d y was made on th e n a tu re o f th e in flu e n c e o f r e s id u e s o f p r e ­
c ed in g cro p s on th e fu n g u s-in d u c e d r o o t r o t o f su g ar b e e ts cau sed by
Aphanomyces c o c h lio id e s D re c h s .
S ix m ature crop r e s id u e s were in c o rp o ra te d in to s t e r i l i z e d and nons t e r i l i z e d s o i l s t h a t were p la n te d t o su g ar b e e ts and in o c u la te d w ith A.
c o c h lio id e s v, The in c o r p o r a tio n o f r e s id u e s d id n o t a p p ea r t o in flu e n c e
th e i n t e n s i t y o f d is e a s e in th e s t e r i l i z e d s o i l . I n th e n o n - s t e r i l i z e d
s o i l a r e d u c tio n o f d is e a s e o f v a ry in g d eg ree was o b ta in e d f o r n e a r ly
e v e ry r e s i d u e . W heat-amended s o i l produced th e g r e a t e s t r e d u c tio n in d is
e a se d s e e d lin g s ,” a l f a l f a , b e an and c o rn were in te rm e d ia te in t h e i r e f f e c t
and b e e t and p o ta to had th e l e a s t a p p a re n t e f f e c t in re d u c in g th e amount
o f d is e a s e .
N itro g e n and phosphorus a n a ly s e s were made o f th e v a rio u s re s id u e s
and each r e s id u e was a d ju s te d t o th e same l e v e l b y th e a d d itio n o f NH^NOg
■and PgOc. The a d d itio n o f n itr o g e n a lo n e in c re a s e d th e grow th o f th e
p la n ts i n th e s t e r i l i z e d s o i l , b u t d id n o t produce n o tic e a b le e f f e c t s on
th e grow th o f th e p la n ts in th e n o n - s t e r i l i z e d s o i l . T here was a h ig h
' in c id e n c e o f d is e a s e in b o th s t e r i l i z e d and n o n - s t e r i l i z e d s o i l s when th e
n itr o g e n le v e l s were a d ju s te d . There was a low p e rc e n ta g e o f d is e a s e d
s e e d lin g s in th e s t e r i l i z e d p o ts when b o th n itr o g e n and phosphorus le v e ls
were a d ju s te d ; how ever, in n o n - s t e r i l i z e d s o i l s amended w ith th e same
m in e ra ls th e i n t e n s i t y o f d is e a s e was h ig h .
S o i l - i s o l a t i o n s were made w ith a m o d ifie d C h este r sam pling tu b e .
F u s a r ia sp p . were th e m ost commonly i s o l a t e d f u n g i. Ten d i f f e r e n t fu n g i
w ere in o c u la te d w ith A,, c o c h lio id e s in s t e r i l i z e d and n o n - s t e r i l i z e d s o i l
p la n te d .w ith su g ar b e e t s . I n t e n s i t y o f d is e a s e in th e s t e r i l i z e d s o i l
ra n g e d from 93 t o 100$ and i n n o n - s t e r i l i z e d s o i l from 22: t o 55$»
-5 -
IMTRODUCTION
The su g a r b e e t fa rm e r i s p ro b a b ly more co ncerned w ith s e e d lin g d i s ­
e a s e s o f b e e ts to d a y th a n he was a few y e a rs a g o .
S in ce th e end o f W orld
War I I ; th e su g ar b e e t in d u s tr y has become r e v o lu tio n iz e d w ith th e ad v en t
o f m e ch an ical equipm ent f o r th in n in g and h a r v e s tin g o f b e e t s .
I t i s im pos­
s i b l e t o use t h i s m achinery and p r a c t i c e s e l e c t i v e th in n in g a s w ith hand
la b o r.
Thus th e im portance o f a u n ifo rm s ta n d o f b e e ts can n o t be o v e r­
em phasized.
I n o rd e r t o o b ta in a u n ifo rm s ta n d ; s e e d lin g d is e a s e s must
be a t a minimum.
There a re a number o f recommended c u l t u r a l p r a c tic e s t o
fo llo w in r a i s i n g b e e t s ; such as. p la n tin g e a r l y t o a v o id th e optimum
grow th^; te m p e ra tu re f o r s e e d lin g p a th o g e n s; u sin g b a la n c e d f e r t i l i z e r p r o ­
grams ; h aving th e seedbed in good p h y s ic a l c o n d itio n and d e la y e d th in n in g .
Most o f th e organism s which cause s e e d lin g d is e a s e s o f b e e ts a re e f f e c t i v e ­
l y c o n tr o lle d b y th e a p p lic a tio n o f a fu n g ic id e t o th e se e d b e fo re p l a n t ­
in g ; b u t up t o th e p r e s e n t tim e no see d tre a tm e n t has b een e f f e c t i v e in
c o n t r o llin g r o o t r o t o f su g ar b e e t s e e d lin g s caused b y Aphanomyces c o c h l i o id e s -D rechs.
A fa n a sie v ( l ) i s o l a t e d s e v e r a l su g a r beet., p athogens from d is e a s e d s e e d ­
lin g s o b ta in e d from th e H u n tley B ranch S t a t i o n ; b u t c o n s id e re d A. c o c h lio id e s t o be th e most im p o rta n t path o g en t o t%ie young b e e t s e e d lin g s in
M o n t a n a T h i s organism u s u a ll y a tta c k s th e young p la n t ab o u t two weeks
a f t e r p la n tin g and produces d a rk le s io n s on th e h y p o c o ty l a t th e s o i l l i n e .
The n e c r o tic d is c o l o r a t io n e x ten d s upward and may re a c h th e c o ty le d o n a ry
l e a v e s . . The c o r t i c a l t i s s u e s m ay b e c o m p le te ly d e s tro y e d ; b u t th e le a v e s
rem ain t u r g i d and r e t a i n t h e i r c o lo r as th e y a s c u la r t i s s u e a p p ea rs t o be
u n a f f e c te d .
-SMcKeen (28) s t a t e d t h a t th e organism is lo c a te d i n th e i n t e r c e l l u l a r
sp aces o f th e c o r te x and he b e lie v e d th e p o r t a l o f e n tr y t o be th e stom ata
on th e h y p o c o ty l.
A fa n a sie v and M orris (^ ) found t h a t a m a jo r ity o f th e
in f e c te d s e e d lin g s re c o v e re d and damage t o th e cro p was p r im a r i ly due to
th e r e ta r d e d grow th o f p la n ts o f low v ig o r .
T h is fungus can n o t be e f f e c ­
t i v e l y c o n tr o lle d b y seed tre a tm e n t b e fo re p la n tin g ; how ever5 many in v e s - .
t i g a to r s .. (5 ,7 ^ 9 ;,10^12J,l4 ^2 2 ) have o b serv ed t h a t b e n e f i c i a l o r d e tr im e n ta l
e f f e c t s on th e i n t e n s i t y o f s e e d lin g d is e a s e may be o b ta in e d b y in c lu d in g
c e r t a i n cro p s in th e r o t a t i o n .
The p u rp o se o f t h i s s tu d y was t o in v e s ­
t i g a t e th e n a tu re o f th e in flu e n c e o f c e r t a i n cro p r e s i d u e s ^ i n s t e r i l i z e d
and n o n - s t e r i l i z e d s o i l s ^ on th e fu n g u s-in d u c e d r o o t d is e a s e o f su g ar b e e ts
cau sed b y A. c o c h li o id e s .
-7 -
LITERATURE REVIEW
Sugar B eet Pathogens
A number o f f u n g i have b een i d e n t i f i e d b y v a rio u s in v e s t ig a to r s as
s e e d lin g pathogens o f su g ar b e e t (B eta v u lg a r is L . ) .
Coons and S te w a rt
( l l ) rev iew ed much o f th e e a r l y work oh s e e d lin g d is e a s e s o f su g ar b e e ts
and th e organism s d e s c rib e d in t h e i r p ap er a s s e e d lin g p athogens w e re :
Phoma b e ta e ( Oud. ) F r . ^ C orticum vagum B » and C. s o la n ! B u r t »P Pythium
debaryanum H essejl Aphanomyces la e v is de B y. , and Pyfchium aphanideraiatum
(Edson) F i t z p . Edson ( l ? ) found t h a t A. l a e v i s . commonly a s s o c ia te d w ith
r o o t r o t o f su g ar b e e t s e e d lin g s in E urope, i s n o t th e same organism as is
i s o l a t e d from d is e a s e d b e e ts in th e U n ited S t a t e s .
Howeverj, he f a i l e d to
re c o g n iz e t h a t b o th organism s b elo n g ed in th e same genus and he named th e
fungus i s o l a t e d in th e U n ite d S ta te s Rheosnorangium a n h a n id e rm a tu s.
In
1928, D re c h s le r ( 15) gave a d e t a i l e d d e s c r ip ti o n o f t h i s o rg an ism , p la c e d
i t i n th e genus AphanomyCes, and named i t Aphanomyces c o c h lio id e s D re ch s.
A fa n a sie v ( l ) in v e s tig a te d b e e t s e e d lin g p athogens in Montana and
i s o l a t e d Phoma, M acrosporium , F u sa riu m 8 R h iz o cto n ia ., Pythium and Aphanomyces
from d is e a s e d su g ar b e e t s e e d lin g s grown a t th e H u n tley B ranch S ta tio n ,
H u n tle y , M ontana.
He c o n sid e re d A. c o c h lio id e s t o be th e most sev e re p a th ­
ogen t o young su g ar b e e t s e e d lin g s grown in i r r i g a t e d , heavy s o i l s in
M ontana.
T h is fungus has b e en r e p o r te d i n most o f th e su g ar b e e t p ro ducing
re g io n s in th e U n ite d S ta te s and is u s u a lly fo u n d in th e heavy s o i l s o f
i r r i g a t e d v a lle y s o f low f e r t i l i t y .
A t th e p r e s e n t tim e see d tre a tm e n ts
ap p ear t o be o f l i t t l e v a lu e f o r c o n tr o llin g th e in f e c tio n o f b e e ts caused
-8 -
b y t h i s organism ( 3 , 8 , 11, 2 6 ) ; how ever, s e v e r a l p o s s ib le c o n tr o l m easures
have been su g g e ste d .
E f f e c ts o f P re c e d in g Crops
Numerous i n v e s t ig a to r s have observ ed t h a t th e grow th o f su g ar b e e ts
i s more v ig o ro u s and th e s ta n d i s more u n ifo rm fo llo w in g c e r t a i n crops in
th e r o ta tio n ^
A fa n a sie v e t a l„ ( 5 ) found t h a t th e s m a lle s t amount o f s e e d ­
lin g d is e a s e i n th e f i e l d o c c u rre d when b e e ts were p la n te d a f t e r c o rn ,
w hereas th e g r e a t e s t amount o f d is e a s e dev elo p ed when b e e ts fo llo w e d b e e ts
in th e r o t a t i o n .
Eoot r o t d is e a s e s were found in in c r e a s in g ly h ig h e r
le v e l s when b e e ts were p la n te d a f t e r c o rn , p o ta to e s , o a t s , a l f a l f a , beans
and b e e ts r e s p e c t i v e l y .
I n t e s t s conducted in th e greenhouse ( 7 ) a l f a l f a , b e a n , c o rn , o a ts
and p o ta to e s p re c e d in g su g ar b e e ts in d is in f e c t e d s o i l in o c u la te d w ith A.
c o c h lio id e s produced no a p p a re n t r e d u c tio n in i n t e n s i t y o f d is e a s e .
In
c o n t r a s t , in n o n - d is in f e c te d s o i l , le s s s e e d lin g d is e a s e was observ ed when
b e e ts fo llo w e d a l f a l f a .
I n i r r i g a t e d r o t a t i o n p l o t s in South D ak o ta, B u ch h o ltz ( 9 ) found A.
c o c h lio id e s t o be abundant in s o i l under a s i x y e a r r o t a t i o n in which
su g ar b e e t s , o a t s , th r e e y e a rs o f a l f a l f a and p o ta to e s, were grow n.
The
cro p o f th e t h i r d y e a r a l f a l f a p l o t was h e a v ily in f e s te d w ith A. cochi I Pid e s and a su g ar b e e t crop f a i l u r e was s u c c e s s f u lly p r e d ic te d in advance
of f i e l d p la n tin g .
Coons e t a l . (12) conducted a cro p sequence experim ent i n which su g ar
b e e ts fo llo w e d sweet c lo v e r , soybeans o r c o rn and th e y o b serv ed t h a t th e
~
9
-
b e e t s ta n d s fo llo w in g soybeans o r c o rn were s i g n i f i c a n t l y b e t t e r th a n th o s e
o b ta in e d when su g ar b e e ts fo llo w e d sw eet c lo v e r . 'I n g reen h o u se ex p erim en ts
Coons and K o tila (lO ) found t h a t grow ing s w e e t.c lo v e r o r a l f a l f a 20 t o 30
days b e fo re p la n tin g b e e ts g r e a t l y in c re a s e d th e dam p in g -o ff o f th e su g ar
b e e t p la n tin g s t h a t fo llo w e d .
Corn grown f o r th e same p e r io d o f tim e
s i g n i f i c a n t l y re d u c e d th e d am p in g -o ff^ w hereas beans as a p re c e d in g crop
a p p a r e n tly d id n o t a l t e r th e d is e a s e in c id e n c e .
The b a s i s f o r com parison
was th e o c cu rren c e o f d is e a s e in su g ar b e e ts In th e check s o i l .
The p a th ­
ogens in t h i s case were d e s c rib e d as " b la c k r o o t" p ro d u cin g o rg an ism s.
P re c e d in g -c ro p ex p erim en ts conducted in th e greenhouse b y H ild eb ran d
and Koch (22) showed th e in c id e n c e o f b la c k r o o t to be lo w est in s o i l s con­
t a in in g in c o rp o ra te d c o m o r soybean r e s id u e s .
A lthough th e r e was a
s l i g h t l y h ig h e r o ccu rren c e o f d is e a s e in s e e d lin g s in th e soybean t r e a t e d
s o i l th a n in th o s e grow ing in s o i l c o n ta in in g c o rn , th e v ig o r o f th e s e e d ­
lin g s in th e soybean s e r i e s was m arkedly g r e a t e r th a n in th e o th e r s e r i e s .
Deems and Young ( l 4 ) a ls o foun d t h a t c o rn , as a p re c e d in g c ro p , was
e f f e c t i v e in d e c re a s in g d is e a s e in c id e n c e on th e b a s is o f f i e l d ex perim ents
co nducted in O hio.
O ats fo llo w e d co rn in e f f e c t i v e n e s s , b u t a l f a l f a and
b e e ts d id n o t d e c re a se the- amount o f b la c k r o o t below th e amounts p re s e n t
in th e c o n tr o l p l o t s .
E f f e c ts o f F e r t i l i z e r s
A fa n a sie v ( 2 ) conducted a s e r i e s o f f e r t i l i z e r e x p erim en ts on lan d
■- 1 0 -
t h a t had b een a l t e r n a t e l y cropped w ith b a r le y and su g ar b e e ts f o r a number
o f y e a rs o The i n i t i a l s o i l f e r t i l i t y was a o red u ced t h a t in, I ^ O , o n ly
6<.06 to n s o f b e e fs p e r a c r e were p ro d u c e d .
P lo ts were t r e a t e d w ith n i t r o ­
gen ( NaNOg and (NHll^ S O iji) 5 phosphorus (P2O^)i, m anure^ . n itro g e n -m a n u re ^
phosphorus-m anure5 n itro g e n -p h o sp h o ru s v and n itro g en -p h o sp h o ru s-m a n u re .
The s m a lle s t y i e l d o f b e e ts (4 .3 9 to n s p e r a c r e ) d u rin g th e f i r s t fo u r
y e a rs was produced in th e u n tr e a te d check p l o t s and th e g r e a t e s t ( 16.27
to n s p e r a c r e ) i n th e p l o t s t r e a t e d w ith n itro g e n -p h o sp h o ru s -manure 5 where
com plete f e r t i l i z a t i o n was u sed w ith a d iv id e d a p p lic a tio n o f n itr o g e n .
The u n tr e a te d check p l o t s c o n ta in e d th e m ost d is e a s e d s e e d lin g s (.72.2$)
w h ereass th e com plete f e r t i l i z e r p l o t s c o n ta in e d th e l e a s t ( l 4 . 2 $ ) .
B ee ts
grown in th e p l o t s f e r t i l i z e d w ith n itr o g e n a lo n e a ls o had a h ig h p e r c e n t­
age o f d is e a s e d p la n ts ($ 5 °3$ )°
Coons e t a l . •( 13) conducted r e p l i c a t e d f e r t i l i z e r t e s t s i n Ohio on
c la y s o i l so. h e a v ily i n f e s te d w ith b la c k r o o t-p ro d u cin g organism s t h a t th e
y i e l d o f u n f e r t i l i z e d p l o t s was n e a r ly $0$ below th e t r e a t e d p l o t .
An ■
a p p lic a tio n o f phosphorus (0 -4 $ -0 ) i n th e amount o f 180 pounds p e r acre'
in c re a s e d th e y i e l d from 6 .7 8 to n s p e r a c r e t o 11.06 to n s p e r a c r e .
The
r e s u l t s gave s t r i k i n g ev id en ce o f th e e f f i c a c y o f p h o sp h ate a p p lic a tio n s
in re d u c in g th e d is e a s e and in in c re a s in g th e y i e ld .
S tu d ie s o f S o i l M ie ro flo ra
S tu d ie s t o d e term in e changes in s o i l m ic ro flo ra as in flu e n c e d by
grow ing v a rio u s crops have been conducted b y numerous i n v e s t i g a t o r s .
S o il
i s o l a t i o n s made by.Deems and Young ( l 4 ) showed' t h a t ' one s e a s o n ’s cropping
-1 1 "
o f s u g a r b e e t s o i l t o a l f a l f a , c o rn , o a t s , and su g ar b e e ts , had l i t t l e . e f ­
f e c t on th e t o t a l numbers o f fu n g i i s o l a t e d .
They fo u n d t h a t P e n lc llliu m
s p p . were more p r e v a le n t in s o i l a f t e r c o rn th a n a f t e r a l f a l f a and b e e t .
Menon and W illiam s ( 2 9 ) ground c o rn and o at p la n ts and in c o rp o ra te d
them in to th e s o i l and l a t e r made i s o l a t i o n s b y th e d i l u t i o n p l a t e method
t o determ in e th e f u n g i p r e s e n t in th e s e s o i l s .
Corn-amended s o i l was
d i s t i n c t in h aving s i g n i f i c a n t l y h ig h e r numbers o f c o lo n ie s ' o f P e n ic illiu m
fu n ic u lo su m , and h ig h e r numbers o f Phycomycetes th a n d id oat-am ended s o i l .
H igher numbers o f c o lo n ie s o f P usariu m s p p . 9 Q lio clad iu m s p p ., P e n ic illiu m
deeumbens and P e n ic illiu m rugulosum were i s o l a t e d from o a t s o i l th a n from
co rn s o i l .
R e c o lo n iz a tio n o f a u to c la v e d s o i l was fo u n d t o be r a p id and a t
th e end o f a two y e a r t e s t p e r io d , th e predom inant fu n g i i n b o th a u to c la v e d
and n o n au to cla v e d s o i l s were a p p ro x im a te ly th e same.
I n ex p erim en ts conducted by A fa n a sie v e t a l , ( 5 ) , s o i l m ic ro flo ra was
a n a ly z e d t o d eterm in e i f d i f f e r e n t cro p s produced any q u a n t i t a t i v e changes
i n th e s o i l m icroorganism s w hich co u ld have an e f f e c t on th e o ccu rren ce o f
su g a r b e e t s e e d lin g d i s e a s e s ,
No s i g n i f i c a n t q u a n tita tiv e v a r i a t i o n s in
th e m ain groups o f th e s o i l m icroorganism s n o rm ally o c c u rrin g in th e s o i l
were fo u n d a f t e r th e v a rio u s c r o p s .
The q u a l i t a t i v e c o m p o sitio n s o f th e
groups were n o t d e te rm in e d .
The q u a l i t a t i v e c o m p o sitio n o f s o il, m ic ro flo ra i s im p o rta n t because
o f th e p o s s ib le r e l a t i o n s h i p betw een th e in c id e n c e o f d is e a s e and some
p a r t i c u l a r organism a s s o c ia te d w ith o r a c tin g on th e p a th o g e n .
The f a c t
t h a t one organism may e x e r t an in flu e n c e upon a n o th e r has b e en known f o r .
-1 2 -
some tim e .
f u n g i.
W eindling ( 32) g iv e s a good re v ie w o f th e a s s o c ia ti o n e f f e c t s o f
H a en sle r and A lle n (20) found t h a t Trichoderm a added t o a s o i l h e av ­
i l y i n f e s te d w ith R h iz o c to n ia re d u c ed see d decay and d am p in g -o ff o f cucumbers
and p eas from 67 and 63$ to 12 and 38$ r e s p e c t i v e l y .
I n a Pythium in f e s te d
s o i l th e r e d u c tio n s were from 69 and 77$ to 12 and 1-7$ , r e s p e c t i v e l y .
Kommendahl and B rock (24) used f u n g i i s o l a t e d b y th e d i l u t i o n p l a t e
te c h n iq u e to d e c re a se th e v ir u le n c e o f G d b b e rella zeae (Schw .) F e tc h .
'
Four
s p e c ie s o f P e n ic i l l i u m , added s in g ly w ith G. zeae in a u to c la v e d s o i l , d e ­
c re a s e d th e p r o p o r tio n o f b lig h te d co rn s e e d lin g s from 89$ in th e check t o
6 5, 25, 20 and 7$ , depending upon th e s p e c ie s mixed w ith th e p a th o g en .
Fungus and a ctin o m y ce te s i s o l a t e s e x h ib itin g v a ry in g d e g re es o f a n ta g ­
onism t o Pythium a r r he nomanes D re c h s . in a g a r c u ltu r e s were t e s t e d by
Johnson ( 23) f o r t h e i r a b i l i t y t o red u ce Pythium ro o t r o t o f c o rn under
g reenhouse c o n d itio n s .
I s o l a t e s t e s t e d in c lu d e d s p e c ie s o f S trep to m y ce s,
P e n ic lU iu m , A s p e r g illu s ■> S p i c a r i a 5 F u sa riu m 5 G lio b o try s 5 M o n ilia and
Mohosporium.
P la te c u ltu r e s o f 37 a n ta g o n is tic a ctin o m y ce te s and 53 a n ta g ­
o n i s t i c fungus i s o l a t e s were mixed w ith s o i l s which had b een p r e v io u s ly
s t e r i l i z e d and th e n in f e s te d w ith P y th ium.
One week l a t e r c o rn was p la n te d ,
and a llo w ed t o grow f o r two weeks a t w hich tim e th e p la n ts were h a rv e s te d
and th e r o o ts examined f o r d is e a s e .
Seven a ctin o m y ce te s and fiv e .fu n g u s
i s o l a t e s s i g n i f i c a n t l y re d u c ed th e s e v e r i t y o f Pythium r o o t r o t .
The fungus
i s o l a t e s w hich gave s i g n i f i c a n t c o n tr o l o f th e d is e a s e were s p e c ie s o f
S p i c a r i a 5 P e n ic illiu m and A s p e r g i llu s .
-1 3 -
EfiFects o f A n tib io tic s .
The use o f m e ta b o lic p ro d u c ts showing a n t i b i o t i c a c ti o n has been
su g g e s te d by some in v e s t ig a to r s as a p o s s ib le means o f c o n tr o llin g s e e d ­
lin g d is e a s e s .
B a c illu s s u b t i l u s , a b a c te riu m f r e q u e n tly i s o l a t e d from
i n f e s te d su g ar b e e t s o i l in N ebraska, when in o c u la te d in to s t e r i l i z e d s o i l
was shown b y D unleavy ( l 6 ) t o g r e a t l y d e c re a se b e e t s e e d lin g dam ping-off
cau sed by R h iz o c to n ia sp p .
I f an e x t r a c t from t h i s organism was added t o
a n u t r i e n t a g a r ..on w hich R h lz o c to n ia was g row ing, th e fungus was g r e a t l y
in h ib ite d .
S treptom yces v e n e z u e la e E h r lic h , a s o i l - i n h a b i t i n g a c tin o m y c e te , was
shown b y G o ttlie b and S im in o ff ( 19 ) t o produce th e a n t i b i o t i c C hlorom ycetin
i n unamended s o i l .
A g r e a t e r amount o f t h i s a n t i b i o t i c was produced in '
a lfa lfa -a m e n d e d s o i l th a n in s o i l t o w hich c o rn s to v e r o r soybean stra w
was ad d ed .
m y c e tin .
Oat s tra w and s t a r c h gave no d e te c ta b le p ro d u c tio n o f C hloro­
When 50 PS o f C hlorom ycetin were added p e r gram o f n o n - s t e r i l e
s o i l th e b a c t e r i a l p o p u la tio n was n e a r ly doubled in sev en d a y s, w hereas th e
fungus p o p u la tio n rem ained r e l a t i v e l y c o n s ta n t.
McKeen ( 2 8 ) was a b le t o produce d is e a s e - f r e e su g ar b e e t s e e d lin g s in
Aphanomyces in f e s te d s o i l b y soakin g th e see d in a s tro n g s o lu tio n o f
s tre p to m y c in f o r 48 h o u r s .
The e f f e c t o f t h i s a n t i b i o t i c , produced b y th e
v
actin o m y ce te S treptom yces g r is e u s (K rain sk y ) Waks. and H e n ., may in d ic a te
th e im portance o f a n ta g o n i s tic m icroorganism s in c o n tr o llin g A. c o c h lio id e s
MATERIALS' AMD METHODS
The n a tu re o f th e in flu e n c e o f s i x d i f f e r e n t p re c e d in g cro p s on th e
fu n g u s-in d u c e d r o o t r o t o f s u g a r b e e ts caused b y Aphanomyces c o c h lio id e s
was s tu d ie d .
R esid u es o f th e s e cro p s were in c o rp o ra te d in to s o i l which
was th e n p la n te d t o su g ar b e e t s ,
R esidue's were a n a ly z e d f o r t h e i r n i t r o Cl
gen and phosphorus c o n te n ts , and a l l w e re . a d ju s te d t o th e same l e v e l o f
f e r t i l i t y w ith r e s p e c t t o th e s e two elem en ts t o in v e s t ig a te t h e i r e f f e c t
on th e d is e a s e o f b e e t s .
A s im ila r t e s t was conducted in w hich th e a sh o f
th e s e r e s id u e s was in c o rp o ra te d in to th e s o i l .
S o i l i s o l a t i o n s of r e p r
r e s e n t a t i v e m ic ro flo ra were made and t h e i r a n t i b i o t i c e f f e c t , on A. c o c h l i oid e s was s tu d ie d .
P rec e d in g Crops
The e f f e c t o f p re c e d in g cro p s on th e incidence- o f th e s e e d lin g d is e a s e
o f su g ar b e e ts caused b y A. c o c h lio id e s was t e s t e d in s o i l t o which th e
above-ground p a r t s o f th e fo llo w in g m ature cro p r e s id u e s were added:
a l f a l f a , b e a n , b e e t , c o rn , p o ta to , and w h e a t.
The cro p s from which th e
r e s id u e s were o b ta in e d were grown and h a rv e s te d a t th e H u n tle y B ranch
S t a t i o n , a i r d r ie d , and th e n ground f i n e l y .
A heavy c la y s o i l was o b ta in e d ,
from th e H u n tley B ranch S ta tio n and b ro u g h t t o Bozeman f o r u se in th e
g reenhouse t e s t s .
S ix ty 7 -in c h c la y p o ts were f i l l e d w ith th e s o i l and u sed in th e s e
te s ts .
T h i r ty o f th e s e p o ts w e re ■steam s t e r i l i z e d f o r f o u r h o u rs a t 15
pounds p r e s s u r e t o e lim in a te most o f th e e x i s t i n g s o i l m ic r o f l o r a .
Each
-1 5 -
r e s id u e tre a tm e n t c o n s is te d o f fo u r s t e r i l i z e d p o ts and f o u r n o n - s t e r i l i z e d
p o ts ,
Twelve p o ts w ith o u t in c o rp o ra te d cro p re s id u e s e rv e d as c o n t r o l s 'f o r
n a t u r a l i n f e s t a t i o n p r e s e n t in th e s o i l .
S ix o f th e s e p o tSi, th r e e s t e r i l i z ­
ed and th r e e n o n - s t e r i l i z e d , were in o c u la te d w ith Aphanomyces inoculum and
th e o th e r s ix p o ts were n o n -in o c u la te d .
Each p o t was amended w ith, 1 1 .4 g
o f r e s id u e ( e q u iv a le n t to two to n s p e r a c r e ) .
Twenty segm ented su g ar b e e t
seed s (G, W. 35.9X t r e a t e d w ith New Improved C eresan a t th e r a t e o f th r e e
ounces p e r 100 pounds o f s e e d , were p la n te d in each p o t .
A f te r th e seeds were p la n te d , an Aphanomyces inoculum was poured over
th e to p o f th e s o i l in th r e e o f th e f o u r p o ts in b o th th e s t e r i l i z e d and
n o n - s t e r i l i z e d groups f o r each r e s id u e .
The inoculum was p re p a re d b y grow ­
in g A. c o c h lio id e s on an oatm eal a g a r medium u n t i l th e m y c e lia l grow th
.
co v ered th e e n t i r e s u rfa c e o f th e medium in a s ta n d a rd P e t r i d is h .
T his
grow th was th e n sc ra p e d from th e d is h in to a c o n ta in e r o f d i s t i l l e d w a te r,
and mixed in a W aring B lendor .fo r ab o u t 10 sec o n d s.
inoculum were added to each p o t o f s o i l .
A p p ro x im ately 30 ml o f
One P e t r i d is h o f Aphanomyces
c u ltu re , was u sed f o r each in o c u la te d p o t .
The b e e ts were a llo w ed t o grow f o r ab o u t s ix .weeks a f t e r p la n tin g ,
d u rin g w h ic h ,tim e p e r io d ic re a d in g s were ta k e n to d e term in e th e number o f
h e a lth y and d is e a s e d s e e d lin g s p r e s e n t.
At th e end o f th e six-w eeks grow ­
in g p e r io d , a l l b e e ts were h a rv e s te d and checked f o r th e c h a r a c t e r i s t i c
symptoms o f th e d is e a s e .
Four c o n se c u tiv e p la n tin g s o f b e e t s , each h aving
a grow ing p e r io d .o f about s i x w eeks, were made in t h i s same s o i l .
- 16-
N itro ^ e n D e te rm in a tio n
An a n a ly s is f o r t o t a l n itr o g e n and t o t a l phosphorus c o n te n ts of each
r e s id u e was made t o d eterm in e i f any o f th e e f f e c t s fo u n d w ith th e v a rio u s
r e s id u e s c o u ld be a s c r ib e d t o a f e r t i l i z a t i o n f u n c tio n .
:
The a n a ly s is f o r t o t a l n itr o g e n c o n te n t o f each r e s id u e was done b y
th e m ic ro k je ld a h l method d e s c rib e d in th e O f f i c i a l Methods o f A n a ly sis o f
th e A s s o c ia tio n o f A g r i c u l t u r a l C hem ists ( 3 0 ) .
A p p ro x im ately 150 rag
sam ples o f each r e s id u e in f o u r r e p l i c a t i o n s were p la c e d in 10 ml d ig e s ­
tio n f la s k s .
Two ml o f c o n c e n tra te d HgSC^and two drops o f fum ing HgSO^
were added t o each sample and th e n th e sam ples were p la c e d in an oven f o r
12 ho u rs a t 100° C. t o i n i t i a t e a slow d i g e s t io n .
A f te r th e d ig e s ts were ta k e n from th e oven, HgO-K2SOiti and b o ilin g
c h ip s were added t o each f l a s k and d ig e s tio n c a r r ie d o u t over a low fla m e .
The d ig e s t was c o o le d , d i l u t e d w ith f i v e ml o f d i s t i l l e d w a te r t o d is s o lv e
th e s o l i d s , and p la c e d in th e d i s t i l l a t i o n a p p a r a tu s .
An e x c e ss o f a l k a l i
was added and th e ammonia was s t e a m - d i s t i l l e d in to a 4$ HgBOg s o lu tio n .
The ammonia s o lu tio n was th e n t i t r a t e d w ith s ta n d a rd iz e d HCl.
When th e t o t a l n itr o g e n c o n te n t o f each re s id u e was e s ta b lis h e d , a l l
r e s id u e s were a d ju s te d t o th e l e v e l o f th e re s id u e c o n ta in in g th e h ig h e s t
p e rc e n t o f n itr o g e n by. adding HHitHOg.
The re s id u e s p lu s HEjtHOg were
in c o rp o ra te d in to th e s o i l and l e f t f o r one week to be c o lo n iz e d b y s o i l
*
m icro o rg an ism s. P la n tin g and in o c u la tin g w ere done a s d e s c rib e d f o r th e
p re c e d in g cro p t e s t s .
-
-1 7 -
Phosphorus D e te rm in a tio n
A m o d if ic a tio n o f A lle n ’s method ( 6 ) f o r d e te rm in in g t o t a l phosphorus
c o n te n t was u s e d .
The m o d ific a tio n s were th o s e ad o p ted b y th e Montana
S ta te C o lleg e C hem istry D epartm ent f o r r o u ti n e phosphorus a n a ly s e s .
In
t h i s p ro c e d u re , a 0 .2 g sample o f each r e s id u e was d ig e s te d w ith 10 ml o f
c o n c e n tra te d HNOg and .15 ml o f 60% HClOij. and e v a p o ra te d t o n e ar d ry n ess
on an e l e c t r i c h o t p l a t e .
The d ig e s t was t r a n s f e r r e d w ith d i s t i l l e d w a te r
in to a 100 ml v o lu m e tric f l a s k and made t o volum e.
A 10 m l a liq u o t of
t h i s s o lu tio n was t r a n s f e r r e d t o a 25 ml t e s t tu b e and two ml o f 10 N
EgSOlj., two ml o f am id o l, and one ml o f m olybdate s o lu tio n were added.
T h is was th e n d i l u t e d t o 25 ml w ith d i s t i l l e d w ater and a llo w ed to s ta n d
f o r 30 m inutes t o a llo w f o r c o lo r d ev elo p m en t.
P e rc e n t l i g h t tra n s m is s io n
o f th e v a rio u s sam ples was r e a d in th e Beckman Model "B" S p e c tro p h o to m e te r.
A ll ground r e s id u e sam ples were a d ju s te d to c o n ta in th e same amount
o f phosphorus by adding PgO^ i n th e form o f t r e b l e -su p e r -p h o s p h a te « The
r e s id u e s p lu s NH^NO^ and PgO^ were in c o rp o ra te d in to th e s o i l and l e f t f o r
one week f o r c o lo n iz a tio n b y s o i l m icroorganism s b e fo re p la n tin g th e su g ar
b e et seed.
P la n tin g and in o c u la tin g were done as d e s c rib e d f o r th e
p re c e d in g -c ro p t e s t s .
A shing o f R esid u es
The p o s s i b i l i t y t h a t any e f f e c t on th e d is e a s e a f t e r th e in c o rp o ra ­
t i o n o f cro p r e s id u e s may be a r e s u l t o f any o rg a n ic c o n s ti tu e n t o f th e
r e s id u e was in v e s t ig a te d b y a sh in g th e v a rio u s r e s id u e s and in c o rp o ra tin g
-1 8 -
th e a sh in to th e s o i l .
By a sh in g th e r e s id u e s th e o rg a n ic compounds would
be degraded and any e f f e c t re c e iv e d b y th e p la n ts would be from th e a sh .A p p ro p ria te amounts o f th e s i x r e s id u e s were w eighed ou t and c h a rre d in
p o r c e la in e v a p o ra tin g d is h e s .
The d is h e s were th e n p la c e d in a m u ffle
fu rn a c e where th e te m p e ra tu re was g r a d u a lly in c re a s e d from 0°C. t o 750®C. 9
and h e ld a t th e l a t t e r te m p e ra tu re f o r a p p ro x im a te ly fo u r h o u r s .
A f te r c o o lin g , th e a sh i n each d is h was d is s o lv e d in 10 ml o f 6 N HCl
and th e r e s u l t i n g s o lu tio n a d ju s te d t o a pH o f 6 .2 o r 6 .3 b y a d d itio n o f
6 N HaOH.
The pH a d ju stm e n t was made w ith a Beckman Model "G" pH m e te r.
The combined s o lu tio n , w hich c o n ta in e d th e a sh o f 102.6 g o f r e s id u e , was
d i l u t e d t o a volume o f 900 ml and 100 ml a liq u o ts were p o u red on th e s o i l
i n each p o t im m ediately a f t e r p la n tin g w ith 20 segm ented su g a r b e e t s e e d s .
I n o c u la tio n o f each p o t w ith 30 ml o f Aphanomyces inoculum was c a r r ie d ou t
in th e same m anner-as f o r th e p re c e d in g -c ro p e x p e rim e n ts .
I s o l a t i o n o f S o il M icroorganism s
T o .d e te rm in e i f th e r e were changes in s o i l m ic ro flo ra among th e
d i f f e r e n t p la n tin g s and s o i l s amended w ith d i f f e r e n t ty p e s o f r e s id u e s ,
and w hether an in c re a s e o r a d e c re a se in i n t e n s i t y o f d is e a s e co u ld be
a s s o c ia te d w ith a q u a l i t a t i v e change in th e m ic r o f lo r a , over 1000 i s o l a ­
ti o n s were made from th e s o i l .
The i s o l a t i o n te c h n iq u e u sed was d e s c rib e d
b y MacWith e y (2 7 ) .
A m o d ifie d C h e ste r tu b e was made b y h e a tin g th e c e n te r o f a 10 cm
p ie c e o f s i x mm g la s s tu b in g and draw ing th e tu b e out t o ab o u t 15 cm in
le n g th .
T h is p ie c e was th e n broken in to two p ie c e s , each h av in g a
-1.9”
c a p i l l a r y w ith a p p ro x im a te ly a one mm o r i f i c e .
The tu b e s were p la c e d in a
250 ml g la s s b e a k e r and su p p o rte d v e r t i c a l l y b y a sm all,, square., w ire
s c re e n a t th e s i d e .
Three p e r c e n t.w a te r - a g a r medium was p o u red in to th e
b e a k e r u n t i l t h e . medium was about I cm above th e to p o f th e c a p i l l a r y .
The tu b e s were p lu g g ed w ith c o tto n and a u to c la v e d f o r 45 m in u te s .
c o o lin g , each tu b e .w as capped w ith a P a ra film s t r i p .
A fte r
F iv e tu b e s were
in s e r t e d in th e s o i l . i n each 7 -in c h p o t and l e f t f o r ab o u t sev en days f o r
c o lo n iz a tio n .
When th e tu b e s were c o lle c te d th e ex cess s o i l was wiped
o f f w ith w a te r-m o is t cheese c l o t h .
Then each c a p i l l a r y was w iped w ith an
a lc o h o l-m o is t cheese c lo th and broken, o f f ab o u t 15 mm from th e c a p i l l a r y
end.
The c a p i l l a r i e s from each p o t were p la c e d in a P e t r i d is h c o n ta in in g
a 2$ w a te r-a g a r medium.
I n about 24 ho u rs a r a d i a l grow th o f mycelium c o u ld be seen growing
from th e end o f th e c a p i l l a r y in th e medium, p ro v id in g th e tu b e had been
c o lo n iz e d . ' A f te r th e c o lo n y was ab o u t 15 t o 20 mm in d ia m e te r, a s e c tio n
o f medium c o n ta in in g mycelium was removed from th e m argin, o f th e colony
and p la c e d upon a p o ta to - d e x tr o s e - a g a r s l a n t .
.Most, o f th e c u ltu r e s .so
o b ta in e d were i d e n t i f i e d on w a te r-a g a r medium in P e t r i d is h e s o r on EDA i n
t e s t .tu b e s .
A n tib io s is
The fo llo w in g method was u sed in ah a tte m p t t o d e term in e a n t i b i o s i s
o r p ro b io s i s t o A. c o ch lio id .es b y th e most commonly, i s o l a t e d organism s
from th e s o i l u sed in th e s e t e s t s .
P e t r i d is h e s , p oured w ith cornm eal-
^igar medium, were in o c u la te d on o p p o s ite s id e s w ith s e c tio n s o f medium
-2 0 -
c o rita in in g th e t e s t organism and s e c tio n s o f medium c o n ta in in g A0 c o c h liQi d e s o As th e mycelium from each organism -approached t h a t o f th e o th e r ,
th e c u ltu r e s were o b serv ed f o r any i n h i b i t i o n o r s tim u la tio n o f grow th.
The w id th o f th e zone o f d e m arcatio n betw een th e two c u ltu r e s serv ed as
a m easure o f th e d eg ree o f i n h i b i t i o n .
I f any organism e x h ib ite d e i t h e r
an i n h i b i t o r y o r s tim u la to r y e f f e c t tow ards A. c o c h li o id e s , i t was t e s t e d
fu rth e r.
F o r a d d i t i o n a l t e s t i n g , th e same ty p e o f medium was p o u red in to a
P e t r i d is h in a th r e e t o fo u r mm la y e r .
On to p o f t h i s medium was p la c e d
a d i a l y s i s membrane ( Cenco 70158 D 5 6 ) w hich had b een s t e r i l i z e d b y th e
method d e s c rib e d by Hansen and Snyder ( 2 l ) f o r th e
o f b io lo g ic a l m a te ria ls .
g aseo u s s t e r i l i z a t i o n
Two ml o f p ro p y le n e oxide were d e liv e r e d t o a
m o ist f i l t e r p a p er in s e r te d in th e l i d o f a one l i t e r b o t t l e .
The d i a l ­
y s i s d is c s were p la c e d in th e b o t t l e , th e l i d was screw ed on t i g h t l y and
th e b o t t l e in v e r te d .
A f te r 2k hou rs th e l i d was lo o sen ed t o a llo w th e
p ro p y le n e oxide t o d i s s i p a t e .
T h e . s t e r i l e d i a l y s i s d is c s were p la c e d upon th e medium w hich was
p o ured f i r s t and th e n a n o th e r la y e r o f medium added t o th e upper s u rfa c e
o f th e d i a l y s i s membrane.
o rganism .
T h is upper la y e r was in o c u la te d w ith th e t e s t
A f te r th e m y c e lia l grow th had c o m p le tely co v ered th e upper
s u r f a c e , th e membrane was removed and s e c tio n s o f medium were c u t from
th e b ottom la y e r and p la c e d n ex t t o s e c tio n s o f medium c o n ta in in g A.
c o c h lio id e s in o c u la te d in f r e s h l y p o ured d i s h e s .
The organism s t h a t e x p re sse d an i n h i b i t o r y e f f e c t upon th e path o g en
£
“
21
—
were c u ltu r e d and in o c u la te d w ith A. c o c h lio id e s in th e p o ts in th e g re e n ­
house .
D ise a se re a d in g s were ta k e n p e r i o d i c a l l y t o a s c e r t a i n any d i f ­
fe re n c e s in p a th o g e n ic ity .
-2 2 -
KESULTS.
R esidue E xperim ents
F o u r t e s t s were conducted t o s tu d y th e e f f e c t s o f cro p re s id u e s on
th e in c id e n c e o f s e e d lin g d is e a s e o f b e e ts caused b y Aphanomyces c o c h lio id e s o The f i r s t r e s id u e t e s t was begun on F e b ru a ry 2h} 1,957.
The r e s ­
id ue and inoculum w ere in c o rp o ra te d in to th e s t e r i l i z e d and" n o n - s t e r i l i z e d
s o i l s on th e same d a te as th e b e e ts were p la n te d .
days s e e d lin g s began t o em erge.
In ab o u t f i v e t o s ix
The f i r s t re a d in g was made ab o u t te n days
a f t e r p la n tin g t o d e te rm in e th e t o t a l number o f p la n ts in each tr e a tm e n t,
I
W eekly re a d in g s were ta k e n u n t i l th e b e e ts were h a rv e s te d a t th e end o f
th e six-w eek grow ing p e r io d .
T able I g iv e s th e number and p e rc e n ta g e o f
h e a lth y and d is e a s e d S e e d lin g s f o r t h i s t e s t in th e s t e r i l i z e d and nons te riliz e d s o ils .
I n th e s t e r i l i z e d s e r i e s , b e e ts p la n te d in corn-am ended s o i l had th e
h ig h e s t in c id e n c e o f d is e a s e ( 6l$ ) fo llo w e d b y bean (hkfo)? a l f a l f a (10%),
w heat ( 33%); in o c u la te d check ( 28%), b e e t ( 19%), p o ta to ( 12%) and nonin o c u la te d check ( 8%).
The. check p o ts in t h i s s e r i e s may
have p o s s ib ly
become co n tam in ated as a r e s u l t o f s p la s h in g w a te r d u rin g th e w a te rin g o f
b e e ts in a d jo in in g in o c u la te d s o i l .
The n o n - s t e r i l i z e d p o ts showed th e
h ig h e s t p e rc e n ta g e o f d is e a s e d p la n ts w ith th e beet-am ended s o i l (81%)
tm d th e lo w est p e rc e n t in th e a lfa lfa -a m e n d e d s o i l (3 l% ).
The s o i l amended
w ith p o ta to had 55% d is e a s e d p l a n t s , w ith c o rn 53%, b ean ! 7%, and wheat
39%«
There were 78% d is e a s e d p la n ts in th e n o n -in o c u la te d checks and 89%
in th e in o c u la te d c h e c k s.
-2 3 T a b le I .
E f f e c t o f r e s id u e s o f s i x d i f f e r e n t c ro p s on d is e a s e o f su g a r
b e e t s g ro w n i n s t e r i l i z e d a n d n o n - s t e r i l i z e d s o i l s i n o c u l a t e d
w ith A . c o c h lio id e s .
S te r iliz e d S o il
R esidue
P ot
No.
A lf a lf a
I
2
3
A ve.
Ck.
I
2
3
A ve.
Ck.
I
2
3
A ve.
Ck.
I
2
3
A ve.
Ck.
I
2
3
A ve.
Ck.
I
2
3
A ve.
Ck.
I
2
3
A ve.
I
2
3
A ve.
Bean
B eet
Corn
P o ta to
Wheat
In o c .
Check
N on-Inoc.
Check
"xH =Iiealthy
T o ta l
No.
E o n - S te r iliz e d S o il
Number
P e rc e n t
H* D*
H D
16
13
21
10
10
20
11
19
21
23
24
12
10
17
15
9
10
18
l6
19
27
17
2k
22
16
18
18
23
14
19
21
8
4
9
6
17
16
6
17
15
21
30
2k
24
27
25
27
23
21
19
21
13
18
9
8
9
16
10
33
33
26
20
26
15
16
13
16
23
17
15
20
20
20
23
20
18
D= d iseased
3
11
10
8
2
12
7
6
8
3
10
2
2
5
5
13
5
Il
10
2
9
0
2
4
2
8
9
I
6
0
6
11
3
7
2
0
3
2
81
48
50
60
91
50
59
60
56
85
63
92
89
81
74
38
45
35
39
88
70
100
93
88
90
62
50
89
67
100
77
58
81
72
88
100
87
92
19
52
50
40
9
50
4l
4o
44
15
37
8
11
19
26
62
55
65
61
12
30
0
7
12
10
38
50
11
33
0
23
42
19
28
12
0
13
8
T o ta l
No.
18
16
17
17
14
8
21
10
13
I
10
7
16
ll
19
6 ~
15
5
9
15
26
l4
12
17
21
12
20
20
17
15
25
30
19
25
17
16
18
17
Number
H D
P e rc e n t
H D
8
13
12
11
8
6
3
7
5
I
2
2
0
I
17
0
12
3
5
2
11
6
6
8
13
10
4
16
10
6
9
11
7
9
9
6
9
8
45 55
81 19
71 29
66 34
57 43
75 25
l4 86
70 30
53 47
100
0
20 80
29 71
0 100
16 84
90 10
0 100
80 20
60 4o
47 53
13 87
42 58
43 57
50 50
45 55
62 38
53 17
20 80
80 20
61 39
4o 60
36 64
37 63
37 63
37 63
53 47
38 62
50 50
47 53
10
3
5
6
6
2
18
3
8
0
8
5
16
10
2
6
3
2
4
13
15
8
6
10
8
2
16
4
7
9
16
19
12
16
8
10
9
9
-2 k-
The b e e t s e e d lin g s grow ing in th e c o rn , p o ta to , and wheat-amended
s o i l s , in b o th s t e r i l i z e d and n o n - s t e r i l i z e d s e r i e s , were s m a ll and
y ello w (s e e F ig u re l ) .
The r o o ts o f th e p la n ts in th e w heat s o i l Were
g r a y is h in c o lo r , had a slim y a p p e a ra n c e , and were v e ry much red u ced in
le n g th as compared t o th e p la n ts in a l f a l f a o r bean-am ended s o i l s .
The second re s id u e experim ent was begun on A p r il 12, 1,957* in th e
same s o i l as was used in th e - f i r s t t e s t .
The r e s u l t s o f t h i s t e s t (T able
I I ) i n g e n e r a l show h ig h e r p e rc e n ta g e s o f in f e c te d p la n ts in b o th s t e r ­
i l i z e d and n o n - s t e r i l i z e d s o i l s th a n were o b serv ed in th e f i r s t e x p e rim e n t.
I n th e s t e r i l i z e d s e r i e s , th e bean-am ended s o i l had 97% d is e a s e d b e e t
p l a n t s , b e e t 87%, c o rn 84%, a l f a l f a 78%, w heat 75%* in o c u la te d check 74%,
p o ta to 72% and n o n -in o c u la te d check 6%.
The in o c u la te d check had th e
g r e a t e s t number o f in f e c te d p la n ts (8,9%) in th e n o n - s t e r i l i z e d s o i l f o l ­
lowed b y p o ta to ( 83%), n o n -in o c u la te d check ( 78%), b e e t ( 68%), co rn (64%),
b ean (6l% ), a l f a l f a (59%) and w heat ( 51%).
A t h i r d p la n tin g in th e same s o i l was made on May 2 7 , 1957°
In t h i s
ex perim ent (T able I I I ) , th e s t e r i l i z e d s o i l showed no d is e a s e o f b e e ts in
th e n o n -in o c u la te d checks in c o n tr a s t t o 91% in f e c tio n in th e in o c u la te d
ch eck , 51% d is e a s e d p la n ts in th e p o ts w ith a l f a l f a and b e an r e s id u e s ,
55% i n th e b e e t s o i l , 6l% i n th e co rn s o i l , 62% in th e p o ta to s o i l and
65% in th e w heat s o i l .
The n o n - s t e r i l i z e d s o i l had t h e ,h i g h e s t p e r c e n t­
ages of d is e a s e d b e e ts in th e in o c u la te d check ( 76%) fo llo w e d b y p o ta to amended s o i l ( 70%), n o n -in o c u la te d check ( 60%), and s o i l s amended w ith
b e e t, (5.9% ), a l f a l f a ( 56%), bean (55%), c o rn (51%) and w heat r e s id u e s (42%).
-2 5 -
F ig u re I .
Sugar b e e ts growing in s t e r i l i z e d s o i l amended w ith v a rio u s
crop r e s id u e s and in o c u la te d w ith A. c o c h li o id e s . P o ts from
l e f t t o r i g h t a re amended w ith w h e at, p o ta to , b e a n , b e e t and
a I f I a f a r e s id u e s r e s p e c t i v e l y .
- 26T a b le I I .
E f f e c t o f r e s id u e s o f s ix d i f f e r e n t cro p s on d is e a s e o f su g a r
b e e t s g ro w n i n s t e r i l i z e d a n d n o n - s t e r i l i z e d s o i l s i n o c u l a t e d
w ith A . c o c h lio id e s .
S te r iliz e d S o il
R esidue
P ot
No.
T o ta l
No.
A lfa lfa
I
2
3
A ve.
Ck.
I
2
3
A ve.
Ck.
I
2
3
A ve.
Ck.
I
2
3
A ve.
Ck.
I
2
3
A ve.
Ck.
I
2
3
A ve.
Ck.
I
2
3
A ve.
I
2
3
A ve.
12
9
9
10
16
8
10
11
10
23
8
8
5
7
14
10
10
14
Il
10
10
19
19
16
19
9
14
Il
Il
24
17
10
7
11
19
14
20
18
Bean
B eet
Corn
P o ta to
Wheat
In o c .
Check
N on-Inoc.
Check
*H“h e a lth y
D“d is e a s e d
E o n - S te r iliz e d S o il
Number
H* D*
P e rc e n t
H D
3
2
0
2
16
0
I
0
0
23
0
3
0
I
12
2
2
I
2
?
I
6
8
5
18
I
5
3
3
20
10
2
0
4
19
13
18
17
25
22
0
16
100
0
10
0
3
100
0
38
0
13
86
20
20
7
16
50
10
32
42
28
92
11
36
27
25
83
59
20
0
26
100
93
90
94
9
7
9
8
0
8
9
Il
10
0
8
5
5
6
2
8
8
13
10
5
9
13
Il
11
I
8
9
8
8
4
7
8
7
7
0
I
2
I
75
78
100
84
0
100
90
100
97
0
100
62
100
87
14
80
80
93
84
50
90
68
58
72
89
64
73
75
17
41
80
100
74
0
7
10
6
T o ta l
No.
11
10
11
11
19
19
9
15
14
30
15
9
12
12
11
16
18
22
19
16
30
14
19
21
15
15
16
26
19
19
14
17
18
16
17
27
21
22
Number
H D
P e rc e n t
H
D
I
4
8
4
5
11
1
7
6
15
5
2
5
4
4
2
11
8
7
2
10
2
I
4
2
9
7
11
9
15
2
3
0
2
5
5
4
5
9
4o
73
4l
26
58
11
47
39
50
33
22
42
32
36
12
61
36
36
12
33
14
5
17
13
60
44
42
49
79
l4
18
0
11
29
19
19
22
10
6
3
6
14
6
8
8
8
15
10
7
7
8
7
14
7
14
12
14
20
12
18
17
13
6
9
15
10
4
12
14
18
15
12
22
17
17
91
60
27
59
74
42
89
53
61
50
67
78
58
68
64
88
39
64
64
88
67
86
95
83
87
4o
56
58
51
21
86
82
100
89
71
81
81
78
-2 7 T a b le I I I .
E f f e c t o f re s id u e s o f s ix d i f f e r e n t cro p s on d is e a s e o f su g a r
b e e t s g ro w n i n s t e r i l i z e d a n d n o n - s t e r i l i z e d s o i l s i n o c u l a t e d
w ith A . c o c h lio id .e s .
S te r iliz e d S o il
R esidue
A lfa lfa
T o ta l
No.
Pot
No.
I
2
3
A ve.
Ck.
Bean
I
2
3
A ve.
Ck.
B eet
I
2
3
A ve.
Ck.
Corn
I
2
3
A ve.
Ck.
P o ta to
I
2
3
A ve.
Ck.
Wheat
I
2
3
A ve.
Ck.
I n o c . -Check I
2
3
A ve.
N on-Inoc.
I
2
Check
3
A ve.
*H =healthy
17
12
2h
18
15
25
16
13
18
22
15
26
20
20
1I
18
19
23
20
22
11
13
Ik
13
12
19
21
18
19
16
12
15
22
16
20
22
26
23
D = diseased
W o n -S te riliz e d S o i l
Number
H* D*
P e rc e n t
H D
T o ta l
No.
Number
H D
P e rc e n t
H D
8
8
8
8
13
8
6
10
8
20
k
16
9
10
IT
k
9
Il
8
22
3
2
10
5
12
5
6
9
7
16
6
k
2
k
20
22
26
23
47 53
67 33
33 67
49 51
87 13
32 68
38 62
77 23
49 51
91 _ 2
27 73
62 38
45 55
45 55
100
0
22 78
47 53
48 52
39 61
100
0
27 73
15 85
71 29
38 62
100
0
26 74
29 71
50 50
35 65
0
100
50 50
27 73
9 91
29 71
100
0
100
0
100
0
100
0
9
17
19
15
15
20
20
11
17
26
17
25
17
20
12
13
21
13
16
22
lk
27
13
18
21
8
16
16
13
21
6
3
8
9
9 10
8
7
10
5
10 10
6 14
6
5
7 10
I l 15
6 11
9 16
8
9
8 12
8
4
10
3
8 13
2
11
8
7
0 22
4 10
10 17
3 10
6 12
4 17
0
8
8
8
4 12
7
7
7 14
6 18
4 12
3 10
4 13
8
15
4
5
2 20
7 11
33
53
47
44
33
50
30
55
45
42
35
36
53
4l
67
23
38
85
49
0
29
37
23
30
19
100
50
25
58
33
25
25
23
24
65
45
9
40
9
k
16
10
2
17
10
3
10
2
11
10
11
11
0
lk
10
12
12
0
8
11
k
8
0
lk
15
9
13
0
6
ii
20
12
0
0
0
0
16
13
18
23
922
18
67
47
53
56
67
50
70
45
55
58
65
64
47
59
33
77
62
15
51
100
71
63
77
70
81
0
50
75
42
67
75
75
77
76
35
55
91
60
- 28-
The f o u r th t e s t was p la n te d J u ly IO5 195T5 and c o n tin u e d in th e same
s o i l a s th e p re v io u s e x p e rim e n ts .
B ee ts grown in th e s t e r i l i z e d s o i l
(T able IV) showed th e s m a lle s t amount o f d is e a s e in th e wheat-amended s o i l
( 6l$ ) and in c re a s in g p e rc e n ta g e s o f in f e c te d p la n ts were o b serv ed in s o i l s
amended w ith b e e t ( 63# ) , co rn ■( 6,9/0) , a l f a l f a (T^o) 5 p o ta to (74$) and b ean
r e s id u e s ( 78$ ) .
The n o n -in o c u la te d and in o c u la te d checks showed 4$ and
70$ d is e a s e d b e e ts r e s p e c t i v e l y .
B ee ts grown in th e n o n - s t e r i l i z e d s o i l
s i m i l a r l y showed th e s m a lle s t amount o f d is e a s e in th e wheat-amended s o i l
(6 2 $ ).
T h is was fo llo w e d b y an in c re a s e in amounts o f d is e a s e when b e e ts
were grown in a l f a l f a - ( 69$ ) , b e a n - ( 69$ ) , b e e t - ( 73^ ) , p o t a t o - ( 78$ ) , and
corn-am ended s o i l s (79$')»
The in o c u la te d check had 84$ d is e a s e as compared
t o 73$ in th e n o n -in o c u la te d check .
P e rc e n ta g e s o f d is e a s e d b e e ts b a se d on th e av erag e o f th r e e r e p l i c a ­
ti o n s in a l l o f th e above m entioned t e s t s a re p re s e n te d in a g r a p h ic a l
form in F ig u re s 2 and 3 .
The r e s u l t s p re s e n te d in th e s e f ig u r e s show t h a t
in th e s t e r i l i z e d in o c u la te d checks (F ig u re 2) th e i n i t i a l d is e a s e i n ­
c id e n c e a v erag e d 28$, b u t in c re a s e d t o ab o u t 70$ f o r th e n e x t th r e e t e s t s .
I n c o n tr a s t t o t h i s , in th e n o n - s t e r i l i z e d s o i l (F ig u re 3 ) th e f i r s t t e s t
showed 63$ d is e a s e i n th e In o c u la te d checks and rem ained betw een 76 t o 89$
in th e o th e r th r e e t e s t s .
I n th e n o n -in o c u la te d checks in th e n o n - s te r -
i l i z e d s o i l th e ran g e o f d is e a s e rem ained from 53 t o 78$ d u rin g a l l fo u r
te s ts .
The a d d itio n o f crop r e s id u e s t o s t e r i l i z e d s o i l d id n o t seem t o
in flu e n c e th e i n t e n s i t y o f d is e a s e f o r th e fo u r t e s t s .
The corn-am ended
s e r i e s was s l i g h t l y h ig h e r in th e f i r s t t e s t , b u t t h i s fo llo w e d th e p a t t e r n
-2 9 T a b l e IV .
E f f e c t o f r e s id u e s o f s ix d i f f e r e n t cro p s on d is e a s e o f su g a r
b e e t s g ro w n i n s t e r i l i z e d a n d n o n - s t e r i l i z e d s o i l s i n o c u l a t e d
w ith A . c o c h lio id e s .
S te r iliz e d S o il
R esidue
A lfa lfa
Pot
No.
T o ta l
No.
I
11
2
11
12
3
A ve.
11
Ck.
21
Bean
I
17
2
19
3
15
A ve.
17
Ck.
20
B eet
I
11
2
18
3
15
A ve.
15
16
Ck.
Corn
I
I^
2
15
16
3
A ve.
15
Ck.
15
P o ta to
I
21
2
25
10
3
A ve.
19
Ck.
13
Wheat
I
15
2
17
11
3
A ve.
14
Ck.
17
In o c .
I
9
2
Check
20
3
19
A ve.
16
N on-Inoc.
I
19
Check
2
18
3
15
A ve.
17
*H =healthy
D“d is e a s e d
N o n -S te r iliz e d S o il
Number
H* D*
P e rc e n t
H D
2
9
8
3
4
8
8
3
2
19
10
7
2 17
2 13
4 13
20
0
4
7
5 13
3 12
5 10
16
0
2 12
8
7
11
5
5 10
0
15
4 17
5 20
4
6
4 14
0
13
4 11
6 11
6
5
5
9
14
3
6
3
4 16
7 12
5 ii
2
17
0
18
0
15
I
17
18
27
33
26
90
41
11
13
22
100
64
28
20
37
100
14
47
31
31
100
19
20
40
26
100
27
35
54
39
82
33
20
37
30
89
100
100
96
82
73
67
74
10
59
89
87
78
0
36
72
80
63
0
86
53
69
69
0
8l
80
60
74
0
73
65
46
6l
18
"67
80
63
70
11
0
0
4
T o ta l
No.
16
20
21
19
17
22
11
15
l6
18
17
27
21
22
12
19
19
12
17
23
22
18
20
20
22
11
15
9
12
18
12
13
13
13
23
15
18
19
Number
H D
5
6
7
6
7
8
2
6
5
5
7
7
3
6
6
4
5
2
4
2
5
6
2
4
6
7
4
2
4
9
2
2
2
2
i4
2
I
6
11
14
14
13
10
i4
9
9
11
13
10
20
18
16
6
15
14
10
13
21
17
12
18
16
16
4
ii
7
7
9
10
ll
ll
ll
9
13
17
13
P e rc e n t
H D
31
30
33
31
4i
36
18
4o
31
28
41
26
14
27
50
21
26
17
21
9
23
33
10
22
27
64
27
22
38
50
17
15
15
16
6l
13
5
27
69
70
67
69
59
64
82
60
69
72
59
74
86
73
50
79
74
83
79
91
77
67
90
78
73
36
73
78
62
50
83
85
85
84
39
87
95
73
-3 0 -
A lf a lf a
T e st Number
B eet
Bean
T e s t Number
Corn
T e s t Number
P o ta to
T e s t Number
F ig u re 2 .
Comparison o f amounts o f b e e t s e e d lin g d is e a s e o b ta in e d in
amended s t e r i l i z e d s o i l in o c u la te d w ith A. c o c h li o id e s .
S o lid l i n e i s in o c u la te d tr e a tm e n t, b ro k en l i n e i s in o c ­
u la te d ch eck .
-3 1 -
Bean
P e rc e n t D isease
A lfa lfa
T e st Number
Corn
P e rc e n t D isease
B eet
T e s t Number
T e st Number
Wheat
P e rc e n t D isease
P o ta to
T e st Number
T e s t Number
F ig u re 3«
T e s t Number
Comparison o f amounts o f b e e t s e e d lin g d is e a s e o b ta in e d in
amended n o n - s t e r i l i z e d s o i l in o c u la te d w ith A. c o c h lio id e s .
S o lid lin e i s in o c u la te d tr e a tm e n t, b ro k en l i n e i s in o c ­
u la te d ch eck .
'
-3 2 -
shoxm b y th e o th e r r e s id u e s in th e o th e r th r e e t e s t s .
I n th e n o n - s te r -
i l i z e d s o i l , th e amended s o i l s produced l e s s d is e a s e th a n th e in o c u la te d
check in e v e ry tre a tm e n t b u t ohe.
The f i r s t t e s t in th e beet-am ended s o i l
had a s l i g h t l y h ig h e r amount o f d is e a s e th a n th e in o c u la te d c h ec k s.
N itro g e n and R esid u e T e s t
The v a r i a t i o n in s iz e and c o lo r o f s u g a r b e e t s e e d lin g s grown in
c e r t a i n o f th e amended s o i l s su g g e ste d t h a t th e v a rio u s r e s id u e s d i f f e r e d
in n itr o g e n c o n te n t.
To in v e s t ig a te t h i s p o s s i b i l i t y a n itr o g e n a n a ly s is ■
o f each r e s id u e was p e rfo rm ed .
Each r e s id u e was a d ju s te d t o th e same
l e v e l o f n itr o g e n b y adding NHlliNOg, as in d ic a te d in T ab le V.
T h is t e s t
was begun on December 11, 1957» and was co nducted in th e same manner as
th e p re v io u s r e s id u e t e s t s .
in T ab le V I.
The r e s u l t s o f t h i s ex p erim en t a r e p re s e n te d
I n th e s t e r i l i z e d s e r i e s , b e e ts grown in a lfa lfa -a m e n d e d
s o i l had th e h ig h e s t p e rc e n t d is e a s e (8 6 $ ), fo llo w e d b y b ean and b e e t (8 0 $ ),
c o rn (7 0 $ ), p o ta to (55$) and wheat (53$)«
The n o n -in o c u la te d check had
12$ d is e a s e d s e e d lin g s compared t o 78$ in th e in o c u la te d c h ec k .
The h ig h ­
e s t p e rc e n ta g e o f d is e a s e d b e e ts f o r th e n o n - s t e r i l i z e d s o i l s e r ie s
o c c u rre d in th e beet-am ended .s o i l ( 89$ ) , and th e d is e a s e d e c re a se d in t h i s
seq u en ce:
c o rn (83$ ) , bean ( 75$ ) , a l f a l f a ( 73$ ) , wheat ( 67$ ) , p o ta to ( 6l $ ) ,
n o n -in o c u la te d check (39$) and in o c u la te d check (3 1 $ ).
l u s t r a t i n g th e s e d a ta i s shown in F ig u re
A b a r g rap h i l ­
•
.
I n e v e ry p o t in th e s t e r i l i z e d s o i l t h a t had been amended w ith
NHiliNOg
and v a rio u s r e s i d u e s , th e b e e ts a t t a i n e d a p p ro x im a te ly th e same h e ig h t and
c o lo r a s in th e a lfa lfa -a m e n d e d s e r i e s (s e e F ig u re 5 )»
T h is was no t
-3 3 -
T ab le V.
P e rc e n ta g e of n itr o g e n in each r e s id u e and w eig h t o f
added t o each sample f o r each p o t o f s o i l .
R esidue
P e rc e n ta g e o f
N itro g e n in
Sample
A lfa lfa
2 .7 8
Bean
1 .0 6
571
B eet
1 .6 3
375'
Corn
O.96
591
P o ta to
1 . 04
566
W h e at
0.21
837
.
Mg M llJOg
A dded/Pot
0
-
T able VI .
34
-
E f f e c t o f n itr o g e n and v a rio u s r e s id u e s on th e amount of
d is e a s e o f su g ar b e e ts grown in s t e r i l i z e d and n o n - s t e r i l i z e d
s o i l in o c u la te d w ith A. c o c h li o id e s .
S t e r i l i z e d S o il
T o ta l
No.
R esidue
Pot
No.
A lfa lfa
I
11
2
17
3
17
A ve.
15
6
Ck.
I
15
2
13
3
19
A ve.
l6
Ik
Ck.
I
11
2
14
3
5
A ve.
10
Ck.
15
I
13
2
11
10
3
A ve.
11
Ck.
8
I
12
10
2
16
3
A ve.
13
6
Ck.
~ u r
I
2
l6
16
3
A ve.
15
Ck.
17
I
10
2
9
l4
3
A ve.
11
I
~T~
2
7
12
3
A ve.
8
Bean
B eet
Corn
P o ta to
Wheat
In o c .
Check
N on-Inoc.
Check
- h e a lth y
D =diseased
N o n -S te r iliz e d S o i l
Number
H* D*
P e rc e n t
H D
T o ta l
No.
0
2
6
3
2
2
2
6
3
5
5
2
0
2
8
2
4
4
3
8
I
5
11
6
4
7
9
6
7
7
0
2
6
3
6
5
11
7
0 100
6 94
35 65
14 86
33 67
13 87
15 85
32 68
20 80
36 64
£5 55
14 86
0 100
20 80
53 47
15 85
36 64
40 60
30 70
100
0
17 83
50 50
69 31
45 55
67 33
50 50
55 45
37 63
47 53
4 l 59
0 100
22 78
43 57
22 78
100
0
72 28
92
8
88 12
11
9
12
11
7
7
4
5
5
16
13
14
4
10
12
16
15
10
14
7
9
13
13
12
9
12
8
10
10
14
15
13
8
12
11
12
12
12
11
15
ll
12
4
13
11
13
12
9
6
12
5
8
7
n
7
6
8
0
Il
5
5
7
2
7
7
10
8
10
10
7
8
8
0
2
I
I
Number
H D
P e rc e n t
H D
6
0
3
3
0
I
0
3
1
4
I
0
I
I
6
2
6
0
3
3
3
4
7
5
4
4
2
4
3
ll
13
9
4
9
ll
6
4
7
55
0
25
27
0
14
0
60
25
25
8
0
25
11
50
12
40
0
17
43
33
31
54
39
44
33
25
40
33
79
87
69
50
69
100
50
33
61
5
9
9
8
7
6
4
2
4
12
12
l4
3
10
6
l4
9
10
ll
4
6
9
6
7
5
8
6
6
7
3
2
4
4
3
0
6
8
5
45
100
75
73
100
86
100
40
75
75
92
100
75
89
50
88
60
100
83
57
67
69
46
61
56
67
75
60
67
21
13
31
50
31
0
50
67
39
P e rc e n ta g e o f
d is e a s e d p la n ts
100
90.
rrt
SCd
S
<
F ig u re 4 .
a
td
CD
m
-p
<L>
0)
FQ
PJ
S
O
O
-P
Cfl
-P
FQ
-P
cd
AJ
U
.
O
I
H
S
1
■
O
O
FJ •
H Al
' u
I
Comparison o f amounts o f b e e t s e e d lin g d is e a s e o b ta in e d
in s o i l s amended w ith r e s id u e s and HH4NO3 and in o c u la te d
w ith A. c o c h lio id e s . (C ro ss h a tc h in g i s n o n - s t e r i l i z e d
s o i l , b la n k i s s t e r i l i z e d s o i l ) .
-3 6 -
o b serv ed in th e n o n - s t e r i l i z e d s o i l .
The b e e t p la n ts were n e a r ly a l l th e
same s iz e and c o lo r , b u t were much s m a lle r and l i g h t e r in c o lo r as compared
t o th e s e e d lin g s in th e s t e r i l i z e d s o i l .
N itro g e n , Phosphorus and R esid u e T e st
The re sp o n se o b ta in e d in th e s t e r i l i z e d s o i l b y th e a d d itio n o f NEijNOg
to th e v a rio u s p o ts made f u r t h e r a n a ly s is o f th e r e s i d u e s . d e s i r a b l e .
A ll
r e s id u e s were a n a ly z e d f o r t h e i r t o t a l phosphorus c o n te n t and each was
a d ju s te d t o th e same l e v e l b y adding PgO^, i n th e form o f t r e b l e - s u p e r ­
p h o s p h a te , t o each p o t .
T ab le V II l i s t s th e p e rc e n t phosphorus in each r e s ­
idue and th e amount o f tre b le -s u p e r -p h o s p h a te added t o e ac h p o t .
As th e r e
were such s m a ll d if f e r e n c e s betw een sam ples in phosphorus c o n te n t, a t e s t
■
a d ju s t in g th e phosphorus l e v e l a lo n e was n o t co n d u cted , b u t b o th n itr o g e n
and phosphorus le v e ls were a d ju s te d in t h i s t e s t .
amount o f NE^NOg added t o each p o t .
See T ab le V f o r th e
"
The r e s u l t s o f t h i s t e s t a re p re s e n te d in T able V I I I .
I n th e s t e r ­
i l i z e d s e r i e s b e e ts grown i n th e wheat-am ended s o i l and in s o i l o f th e nonin o c u la te d ch eck , each had 6$ d is e a s e d p l a n t s .
Of th e th r e e in o c u la te d
check p o t s , one had 65^ d is e a s e d p l a n t s , b u t no b e e t s ' emerged in th e o th e r
two p o t s .
These p o ts were n o t c o n sid e re d a s r e p r e s e n tin g 100$ d is e a s e d
p la n ts as th e r e was no s e e d lin g emergence and i t is p o s s ib le th e y were
m issed d u rin g p l a n t i n g .
S e e d lin g s grown in th e beet-am ended s o i l ,h a d 60$
d is e a s e , fo llo w e d b y b e a n (3 9 ^ ), co rn (2.9$), p o ta to ( 26$ ) and a l f a l f a ( 2^$) . .
The d is e a s e re a d in g s were v e ry low in t h i s t e s t .
r
A d if f e r e n c e in c o lo r and
-3 7 -
F ig u re 5»
Sugar b e e ts grow ing in s t e r i l i z e d s o i l amended w ith v a rio u s
cro p r e s id u e s , n itr o g e n , and in o c u la te d w ith A. c o c h lio id e s .
P o ts from l e f t t o r i g h t a re amended w ith a l f a l f a , b e a n , b e e t ,
c o rn , p o ta to and wheat r e s id u e s .
-
T able V I I .
38
-
P e rc e n ta g e o f phosphorus in each re s id u e and w eig h t o f
tre b le -s u p e r -p h o s p h a te added t o each sample f o r each p o t
of s o il.
R esidue
P e rc e n ta g e o f
Phosphorus in
Sample
A lf a lf a
0 .2 1
0 .0
Bean
0 .1 6
1 3 .8
B eet
0 .1 9
4 .6
Corn
0 .2 0
2 .3
P o ta to
0 .1 7
1 1 .5
Wheat
0 .0 3
4 8 .5
■*TSP - tr e b le -s u p e r -p h o s p h a te
Mg t s :
Added ;
P o t.
-
T able V I I I .
39-
E f f e c t o f n it r o g e n , phosphorus and v a r io u s r e s id u e s on th e
amount o f d is e a s e o f sugar b e e t s grown in s t e r i l i z e d and
n o n - s t e r i l i z e d s o i l in o c u la te d w ith A. c o c h l i o i d e s .
S te r iliz e d S o il
R esidue
A lfa lfa
Bean
B eet
Corn
P o ta to
Wheat
In o c .
Check
M on-Inoc.
Check
=IieaTthy
Pot
Mo.
T o ta l
Mo.
I
11
2
18
3
9
A ve.
12
Ck. - I?
I
24
2
10
12
3
A ve.
15
Ck.
15
I
18
2
25
3
13
A ve.
19
Ck.
13
I
22
2
17
16
3
A ve.
18
Ck.
12
I
12
2
13
3
25
A ve.
17
16
Ck.
I
24
2
19
21
3
A ve.
21
Ck.
17
I
17
2
3
A ve.
17
I
15
2
23
3
23
A ve.
20
D = d isea sed
M o n -S te r iliz e d S o i l
Mumber
H* D*
P e rc e n t
H D
T o ta l
Mo.
Mumber
H D
2
9
14
4
6
3
10
3
0
19
16
8
4
6
9
3
10
6
11
4
9
9
6 19
6
7
7 12
10
3
14
8
0
17
8
8
13
5
12
0
11
1
6
7
6
19
12
4
12
4
24
0
18
1
18
3
20
I
2
15
6 11
6 11
0
15
21
2
21
2
I
19
82
78
67
76
100
£7
4o
75
61
73
50
24
46
40
77
64
100
50
71
100
92
54
76
74
75
100
95
86
94
88
35
35
100
91
91
94
14
20
19
18
18
12
10
15
12
20
15
19
8
l4
24
13
15
7
12
9
10
9
15
11
ll
12
11
9
Il
10
11
13
16
13
~Io
18
18
17
3
6
12
7
13
5
4
7
5
16
2
7
3
4
15
18
22
33
24
0
33
60
25
39
27
50
76
54
60
23
36
0
50
29
0
8
46
24
26
25
0
5
14
6
12
"55
65
0
9
9
6
10
2
5
4
3
6
10
6
5
4
5
5
5
10
7
8
Il
9
6
12
10
9
11
14
7
ll
5
7
6
8
7
4
13
12
5
10
9
9
5
5
6
5
7
3
5
5
6
8
6
4
6
0
4
5
5
5
10
6
8
8
P e rc e n t
H D
21
30
63
38
72
42
40
47
43
80
13
37
37
29
63
31
67
29
42
45
30
67
67
55
45
33
46
56
45
100
64
62
69
65
38
67
55
53
79
70
37
62
28
58
60
53
57
20
87
63
63
71
37
59
33
71
58
55
70
33
33
45
55
67
54
44
55
0
36
38
31
35
62
33
45
47
P ercen ta g e o f
d is e a s e d p la n ts
100
90 .
80.
70
I
6o
I
I
50
4o
%
%
30
%
20
%
S
5
<
F ig u r e 6 .
§
(U
FQ
•P
C
0)
S
CU
FQ
U
O
a
t
PQ
e
-P
Cd
I
U
B
O
1 »
H
Comparison o f amounts o f b e e t s e e d lin g d is e a s e o b ta in ed
in s o i l s amended w ith r e s id u e s ,, NH^NOo, and t r e b le - s u p e r ­
phosphate and in o c u la te d w ith A. c o c h l i o i d e s . (C ross
h a tch in g i s n o n - s t e r i l i z e d s o i l , b lan k i s s t e r i l i z e d s o i l ) .
-4 1 -
s iz e , was n o tic e a b le betw een th e b e e ts in th e s t e r i l i z e d and n o n - s t e r i l i z e d
s o ils .
I n th e s t e r i l i z e d s o i l th e " p la n ts were d a rk e r g re e n in c o lo r and
a p p e a re d t o be l a r g e r th a n th o s e grow ing in th e n o n - s t e r i l i z e d s o i l .
In
•the l a t t e r s e r i e s , beet-am ended s o i l had th e l a r g e s t p e rc e n ta g e o f d is e a s e d
p la n ts ( 71$ ) fo llo w e d by a l f a l f a ( 62# ) , c o rn ( 58# ) , b ean ( 57# ) , wheat ( 55# ) ,
n o n -in o e u la te d check (4 7 # ), and in o c u la te d check ( 35# ) .
F ig u re 6 i l l u s ­
t r a t e s th e s e d a ta .
S o i l M ic ro flo ra I s o la tio n s and A n tib io tic T e sts'
I s o l a t i o n s o f f u n g i were made from the s o i l t o d e term in e w hether th e r e
were n o tic e a b le q u a l i t a t i v e changes in th e m ic ro flo ra fo llo w in g th e in c o r ­
p o r a tio n o f m ature cro p r e s id u e s in to s t e r i l i z e d and n o n - s t e r i l i z e d s o i l .
F iv e m o d ifie d C h e ste r tu b e s were p la c e d in each p o t f o r each re s id u e t e s t
(s e e F ig u re 7 ) .w ith th e e x c e p tio n o f th e f i r s t t e s t in th e s t e r i l i z e d s o i l .
The f u n g i most f r e q u e n tly i s o l a t e d b y t h i s method a re l i s t e d in T ables H
and X.
R e p r e s e n ta tiv e s from each o f th e s e g e n era were t e s t e d in d iv id u a lly
i n - P e t r i d is h e s t o observe any s tim u la to r y o r in h i b i t o r y e f f e c t s on th e
grow th o f A. c o c h li o id e s .
Where a t e s t organism was in o c u la te d in th e same
p l a t e w ith A. c o c h lio id e s , v a ry in g d eg rees o f antagonism were n o tic e d .
Some o f th e c u ltu r e s grew j u s t t o th e p e rip h e ry , o f th e Aphanomyces growth,
some o v e rla p p ed from 5 t o 10 mm, and o th e rs grew c o m p le tely over th e p a th ­
ogen.
There was no d e m arcatio n zone betw een th e d i f f e r e n t m y e elia in any
o f th e d is h e s .
S e c tio n s o f medium ta k e n from below a d i a l y s i s membrane o v e r la id by
medium on w hich th e t e s t organism was g row ing, produced an i n h ib ito r y
I
-
F ig u r e 7 .
42
-
Sugar b e e ts grow ing in s o i l amended w ith r e s i d u e , i l l u s t r a t i n g
th e method o f i s o l a t i n g s o i l f u n g i b y th e m o d ified C h este r
tu b e o
T able IX .
0)
I
•rl
CO
CU
K
A lf a lf a
Bean
B eet
Corn
P o ta to
Wheat
In o c .
Check
W on-Inoc.
Check
S o i l fu n g i i s o l a t e d from s t e r i l i z e d , amended s o i l in o c u la te d
w ith A . c o c h l i o i d e s .
.3
%
o
kCU
•p
CO
CU
Eh
2
3
4
S
C
4
O
O
I
B
o
p
CU
I
U
O
O
O
2
3
4
6
O
O
O
O
O
2
3
4
2
O
O
2
3
4
II
H
•H
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C
£
r—
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3
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11
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8
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O
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S
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K
O
O
O
5
9
4
O
O
O
O
O
I
O
O
O
O
O
I
3
8
7
2
2
O
O
I
I
O
O
O
O
I
O
6
9
6
I
2
O
2
3
4
O
O
O
O
O
O
7
9
7
2
3
4
I
O
2
O
I
O
2
3
4
O
O
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4
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O
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O
O
2
g
-8
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h
EH
O
O
O
I
3
CU
CO
S
O
O
I
7
O
O
O
O
O
2
O
O
O
O
O
I
O
O
I
2
2
O
I
I
O
O
O
O
O
O
4
I
O
I
I
2
2
I
O
O
I
O
O
O
O
O
2
4
I
O
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3
6
7
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5
O
I
O
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O
I
O
4
I
3
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2
6
I
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I
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O
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O
O
2
O
O
O
O
O
O
O
2
O
O
I
O
O
7
8
-4 4 -
T able X.
S o i l fu n g i i s o la t e d from n o n -ste r iliz e d ,a m e n d e d s o i l in o c u la te d
w ith A. c o c h lio id .e s .
•H
a
O
y
Tl
•H
to
Q)
. «
A lfa lfa
O
a
+3
to
0)
B
I
2
3
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a
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CO
9
r—
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I—I
•H
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C
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O
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O
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0
O
O
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o
O
O
O
O
O
12
O
8
7
O
I
O
O
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O
i
O
O
O
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1
Cd
CQ
O
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O
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b
CU
4^
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<D
3
#
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IS
jj
-H
EH
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O
O
O
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CQ
S
3
I
2
O
I
O
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iS
O
13
4
4
Bean
I
2
3
4
5
O
O
O
O
O
O
I
3
5
13
7
5
2
O
O
O
O
O
I
O
O
O
O
O
O
I
I
O
O
O
O
O
O
O
O
2
8
O
5
B eet
I
2
3
4
O
O
O
O
O
O
O
I
7
I
7
6
O
3
O
O
O
O
4
5
O
3
I
O
O
I
2
O
O
O
O
O
6
2
I
2
2
5
O
I
Corn
I
2
3
4
O
2
O
O
O
O
O
O
2
O
6
11
5
O
O
O
O
O
5
I
I
O
O
O
O
I
2
O
O
3
O
O
7
O
O
O
O
9
2
3
P o ta to
I
2
3
4
6
O
O
O
O
O
O
O
O
6
8
12
6
O
O
O
O
O
I
O
I
O
O
O
O
O
4
O
O
O
O
O
2
O
2
O
O
9
O
3
Wheat
I
2
3
4
O
I
O
O
2
O
O
O
4
4
10
7
5
3
I
O
O
O
O
I
O
O
O
O
O
3
4
3
I
O
O
O
3
O
O
O
O
4
O
4
I
2
3
4
2
O
O
O
I
3
I
O
5
5
5
7
3
2
O
O
O
O
5
O
I
O
O
O
O
O
O
O
O
I
O
3
3
2
O
4
O
2
4
I
Non- I noc . 1
Check
2
3
4
I
O
O
O
O
O
O
O
6
I
7
11
I
O
O
O
O
O
2
O
O
O
O
2
O
O
I
O
O
I
I
O
O
O
O
I
In oc.
Check
7
13
4
I
-4 5 -
e f f e e t'u p o n A. e o c h lio id e s f o r e v e r y t e s t c u l t u r e „ When c u ltu r e s o f th e s e
same organism s were in o c u la te d w ith A. e o c h lio id e s in s o i l p la n te d t o su g ar
b e e t s , th e r e was a d is e a s e ran g e from 93 t o 100$ f o r e v e ry p o t in th e s t e r ­
i l i z e d s o i l (s e e T able X l ) ,
There was no r e d u c tio n in th e amount o f d i s ­
e ase in th e s t e r i l i z e d s o i l b y adding th e s e o rg an ism s, b u t in th e nons t e r i l i z e d s o i l a c o n s id e ra b le re d u c tio n in d is e a s e o c c u rre d and th e d is e a s e
ra n g e was from 22 t o 55$ (s e e T able X I I ) .
Three d i f f e r e n t g e n era o f fu n g i
showed a p p ro x im a te ly 50$ r e d u c tio n in th e amount o f d is e a s e in th e nons t e r i l i z e d s o i l a s compared t o th e in o c u la te d check*
A lte r n a r ia (2 2 $ ),
P e n ic illiu m (2 6 $ ), and Pythium (27$) had th e lo w e st amount o f d is e a s e as
compared t o 53$ f o r . t h e in o c u la te d ch eck .
One s p e c ie s o f F u sariu m ( 55$ ) ,
S ta c h y b o try s .(50$) and T richoderm a ( 52$ ) d id n o t show any b e n e f i c i a l e f f e c t
in re d u c in g th e amount o f d is e a s e .
R esid u e Ash T e st
The r e s id u e s were ash ed t o e lim in a te th e p o s s i b i l i t y o f an o rg an ic
p r i n c i p l e e f f e c t i n g th e grow th o f th e p la n ts o r th e p a th o g e n .
When th e a sh
was d is s o lv e d in 10 ml o f 6 W HCl and th e n n e u tr a liz e d w ith 6 W MaOH, a p ­
p ro x im a te ly 3 .5 g o f WaCl were added t o each p o t o f s o i l .
The e f f e c t o f
ad ding t h i s q u a n tity o f s a l t was n o t ta k e n in to c o n s id e r a tio n a t th e tim e
th e t e s t was conducted and a s a r e s u l t th e g e rm in a tio n of. th e b e e t seed s
was v e ry poor and th e s ta n d o f b e e ts was n o t s a t i s f a c t o r y .
son th e d a ta f o r t h i s t e s t a re n o t in c lu d e d in t h i s p a p e r .
For th is r e a ­
-4 6 -
T able X I.
Amount o f d is e a s e o f sugar b e e t s grown in s t e r i l i z e d s o i l in o c ­
u la te d w ith A . c o c h lio id e s and o th er fu n g i is o l a t e d from th e
s o il,
( i s o l a t i o n s from d is e a s e d b e e t s are a l s o l i s t e d . )
C u ltu re s i s o l a t e d from b e e t s .
C u ltu re and
Number
T o ta l No.
B eets
Number
H* D*
Number
Aphan .
Is o l.
No. Aphan.
I s o l . and
O thers
No.
of
O thers
98
17
36
13
P e rc e n t
H
D
A l te r n a r ia
(3SW3-4)
6l
I
Chaetomium
(3SK3-1
53
O 53
O 100
28
21
2
Fusarium
(3SW2-2)
53
O 53
O 100
20
18
9
F usarium
(4N2-5)
68
O 68
O 100
20
44
5
Fusarium
( 4 c 3 - i)
73
O 73
O 100
27
28
0
Penj c i 1 lum
(3SC4-5)
57
4
53
7
93
46
5
0
Pythium
(3C3-4)
65
I
64
2
98
13
36
5
R h iz o c to n ia
(2T2.-1)
67
3
64
4
96
20
39
5
S ta c h y b o try s
(3SW1-5)
59
2
57
3
97
13
45
0
Trichoderm a
(3ST2-3)
64
O 64
O 100
27
32
3
Aphanomyces
(2 004, 6$)
24
O 24
O 100
24
0
0
*H =healthy
D = diseased
60
2
—h 'J —
T able X I I .
Amount o f d is e a s e o f sugar b e e t s grown in n o n - s t e r i l i z e d s o i l
In q c u la ted w ith A. c o c h lio id e s and o th er fu n g i i s o la t e d from
th e s o i l ,
( i s o l a t i o n s from d is e a s e d b e e t s a re a ls o l i s t e d . )
C u ltu re s i s o l a t e d from b e e t s .
C u ltu re and
Number
T o ta l No.
B eets
Number
, H* D*
P e rc e n t
H
D
Number
Aphan.
Is o l.
No. Aphan.
I s o l and
O thers
No.
of
O thers
A l te r n a r ia
(3SW3-4)
54
42
12
78
22
I
4
4
Chaetomium
(3SK3-1)
43
26
17
6l
39
5
10
2
F u sarium
(3SW2-2)
47
21
26
45
55
5
13
7
F usarium
(4N2-5)
60
33
27
55
45
5
13
6
Fusarium
(4C3-1)
81
57
24
70
30
2
20
2
P e n ic illiu m
(3SC^-5)
72
53
19
74
26
12
2
I
Pythium
(3 0 3 -4 )
73
53
20
73
27
O
16
4
E h iz o c to n ia
(2T2-1)
46
30
16
65
35
5
8
3
S ta c h y b o try s
(3SW1-5)
66
33
33
50
50
5
26
4
T richoderm a
(3ST2-3)
59
28
31
48
52
2
15
10
Aphanomyces
(2004, 6 5 )
19
9
10
47
53
3
3
I
*H =healthy
D = d iseased
-
48
-
DISCUSSION
Of th e many ph ases o f th e r o o t d is e a s e problem t h a t m e rit s tu d y , th e
i n v e s t ig a ti o n o f crop r e s id u e e f f e c t s has b een s e le c te d f o r t h i s p r o je c t
b e ca u se knowledge o f th e s e e f f e c t s is b a s ic t o our u n d e rs ta n d in g o f th e
b io lo g y o f th e d is e a s e organism s in th e s o i l and co u ld f u r n i s h a more
r a t i o n a l b a s is f o r d e v elo p in g r o o t d is e a s e c o n tr o l b y s o i l management
p ra c tic e s .
I t is re c o g n iz e d t h a t many o th e r p h ases o f t h i s problem a re
im p o rta n t and a ls o r e q u ir e expanded s tu d y .
' I n stu d y in g th e e f f e c t o f m ature c r o p .r e s id u e s on s e e d lin g d is e a s e o f
su g a r b e e ts cau sed by Aphanomyces c o c h lio id e s D re c h s. , th e r e ap p eared t o
be l i t t l e
i f any e f f e c t, d e riv e d from th e in c o rp o ra tio n o f a re s id u e in to
s te riliz e d s o il.
A lthough in th e f i r s t t e s t th e r e were r a t h e r wide d i f ­
fe re n c e s in th e amount o f d is e a s e o f b e e ts in th e c o rn - ( 6l$ ) and p o ta to amended ( 12$ ) s o i l s , th e s e and th e o th e r amended s o i l s showed s m a ll v a r ­
i a b i l i t y in i n t e n s i t y o f d is e a s e in th e o th e r th r e e t e s t s .
I t is d i f f i c u l t
t o e x p la in th e v a r i a t i o n s n o te d in th e f i r s t t e s t , e s p e c i a l l y s in c e th e s e
v a r i a t i o n s d id n o t occur in l a t e r t e s t s .
P o s s ib ly th e r e was' a more r a p id
b u ild - u p o f th e p ath o g en in th e corn-am ended s o i l th a n in th e o th e r s o i l s .
Many i n v e s t ig a to r s (5 ,1 0 ,1 1 ,1 4 ) have r e p o r te d t h a t co rn grown p r i o r to
b e e ts te n d e d t o red u ce th e amount o f s e e d lin g d is e a s e ; how ever, t e s t s con­
d u c te d in th e greenhouse a re n o t com parable t o f i e l d t e s t s .
Menbn and
-W illiam s ( 2 9 ) found t h a t th e r e l a t i v e fre q u e n c y o f most g roups o f fu n g i
d i f f e r e d in s o i l cropped t o c o rn and t o s o i l amended w ith c o rn r e s id u e .
■4.9There i s a ls o th e p o s s i b i l i t y t h a t organism s p re s e n t in th e r e s id u e , in th e
absence o f c o m p e titio n o f o th e r organism s in th e s t e r i l i z e d s o i l , c o lo n iz e d
th e r e s id u e and th e s o i l and r a p i d l y in h i b i t e d o r s tim u la te d th e r a t e o f
b u ild - u p o f th e p a th o g e n .
I n c o n tr a s t t o th e fin d in g s in th e s t e r i l i z e d s o i l , th e in c o rp o ra tio n
o f cro p re s id u e s ' in to n o n - s t e r i l i z e d s o i l d e c re a se d th e amount o f d is e a s e
o f b e e ts below t h a t fo u n d in th e in o c u la te d check in e v e ry t e s t and f o r a l l
r e s id u e s w ith th e e x c e p tio n o f th e beet-am ended s o i l .
The re d u c tio n in th e
amount o f s e e d lin g d is e a s e o f b e e ts v a r ie d w ith d i f f e r e n t amendments.
W heat-amended s o i l showed th e g r e a t e s t d e c re a se in d is e a s e , a l f a l f a , b e a n ,
and corn" were ab o u t th e same w ith somewhat more d is e a s e th a n found in s o i l
.amended w ith w h eat, and b e e t and p o ta to had th e l e a s t a p p a re n t e f f e c t on
reducing- d is e a s e .
I t i s c o n c e iv a b le t h a t due t o th e ch em ical co m p o sitio n
o f d i f f e r e n t r e s id u e s , one ty p e o f organism m ight b e su p p o rte d b y one ty p e
o f s u b s tr a te in p re fe re n c e t o a n o th e r .
I t was found in t h i s s tu d y t h a t
a l f a l f a had over 13 tim es as much n itr o g e n a s wheat (se e T ab le V) and
seven tim e s as much phosphorus as w heat (s e e T able V I I ) .
P o s s ib ly th e
w heat-am ended s o i l su p p o rte d .a ty p e o f m ic ro flo ra t h a t i n h i b i t e d th e grow th
o f th e p ath o g en o r some o f th e s o i l m icro o rg an ims became p a r a s i t i c upon th e
p a th o g e n .
I t i s p o s s ib le t h a t th e m ic ro flo ra c o lo n iz in g th e w heat s u b s tr a te
stim u la te d th e grow th o f some organism s w hich in tu r n i n h i b i t e d th e d e v e lo p ­
ment o f A.' c o c h li o id e s .
T his in h i b i t i o n c o u ld be th e r e s u l t o f an a n t i ­
b i o t i c produced b y an organism , a p a r a s i t i c r e l a t i o n s h i p betw een th e p a th ­
ogen and a n o th e r o rganism , o r even c o m p e titio n f o r a v a il a b le n u t r i e n t s in
th e s o i l .
-5 0 -
The f a c t t h a t d i f f e r e n t cro p s fa v o r th e o c cu rren ce o f c e r t a i n m ic ro ­
organism s has been shown b y s e v e r a l i n v e s t i g a t o r s .
Deems and Young (14)
fo und t h a t s t r i k i n g l y h ig h e r numbers o f P e n ic illiu m sp p . were i s o l a t e d from
s o i l in w hich co rn had grown as compared t o s o i l in w hich b ean s and a l f a l f a
had grow n.
Menon and W illiam s (2,9) o b serv ed t h a t a l f a l f a ^-cropped s o i l co n ­
ta in e d a h ig h number o f A s p e r g i l l i , o a t s o i l had a h ig h number o f Chaetomium sp p . and wheat s o i l had a high, number o f R hizopus sp p .
S e v e ra l e x p la n a tio n s f o r th e v a r i a t i o n s observ ed in th e amount of
d is e a s e in each s e r i e s and in d i f f e r e n t t e s t s may be c o n je c tu r e d .
The c la y
p o ts u sed in th e s e t e s t s f r e q u e n tly showed poor d ra in a g e , w hich co u ld
in flu e n c e th e w a te r c o n te n t o f th e s o i l .
The same p e rso n w a te re d th e p o ts
each tim e , b u t i t i s p o s s ib le t h a t some p o ts re c e iv e d s l i g h t l y more w a ter
th a n o t h e r s .
The s o i l m o istu re l e v e l i s known t o g r e a t l y in flu e n c e th e
d e n s ity o f inoculum p r e s e n t and th e su b seq u en t amount o f d is e a s e .
McKeen
( 2 8 ) s t a t e d t h a t a t th e optimum te m p e ra tu re and w ater c o n d itio n s , zoospores
a re produced in fo u r t o f i v e h o u rs .
He a ls o e s tim a te d t h a t ab o u t 50,000
zo ospores c o u ld be produced from a p ie c e o f in f e c te d t i s s u e ab o u t one in c h
lo n g .
W ith t h i s inoculum p o t e n t i a l , I t i s im p o rtan t t h a t a l l s o i l have
a b o u t th e same w a te r c o n te n t.
The t e s t s were n o t conducted under c o n tr o lle d te m p e ra tu re c o n d ito n s .
A th e rm o s ta t was s e t a t 75° F . , b u t th e te m p e ra tu re ran g e f l u c t u a t e d from
60° t o 90° F .
A ls o , th e p h o to p e rio d and i n t e n s i t y o f l i g h t r e c e iv e d b y th e
s e e d lin g s v a r ie d a cc o rd in g t o 'th e tim e o f th e y e a r th e t e s t s were co n d u cted .
These f a c t o r s c o u ld c o n tr ib u te t o v a r i a t i o n in d is e a s e in c id e n c e betw een
te s ts .
-5 1
A nother ty p e o f v a r i a b i l i t y was e n co u n te re d in se e d g e rm in a tio n .
p o ts would show 100$ g e rm in a tio n and o th e rs as low as 50$.
Some
A g e rm in a tio n
t e s t conducted in th e la b o r a to r y in d ic a te d t h a t ab o u t rJCffo o f th e seeds were
v ia b le .
I f th e r e was one d is e a s e d p la n t in th e p o t w ith 100$ g e rm in a tio n
and one d is e a s e d p la n t in th e p o t w ith $0$ g e rm in a tio n , tw ic e th e p e r c e n t­
age o f d is e a s e was r e p o r te d f o r th e p o t w ith th e p o o re s t g e rm in a tio n .
The
re a s o n s f o r poor g e rm in a tio n a re unknown, as th e same seed was u sed f o r a l l
te s ts .
I t i s alw ays p o s s ib le t h a t some i n j u r i e s to th e see d embryo o c c u rre d
d u rin g s e g m e n ta tio n .
I t i s a ls o p o s s ib le t h a t some v a r i a t i o n in th e s ta n d
o f b e e ts was due t o th e f a c t t h a t seed tre a tm e n t w ith New Improved C eresan
was n o t c o m p le te ly e f f e c t i v e f o r c o n tr o llin g seed -b o rn e in f e c tio n s and p r e emergence dam ping-off in th e n o n - s t e r i l i z e d s o i l .
When a l l r e s id u e s were a d ju s te d t o th e same n itr o g e n l e v e l as a l f a l f a
th e r e was a h ig h in c id e n c e o f d is e a s e o f b e e ts in b o th th e s t e r i l i z e d and
n o n -s te riliz e d s o ils .
The d if f e r e n c e s in s iz e and c o lo r o f b e e ts t h a t were
n o te d in t h i s t e s t may p o s s ib ly be e x p la in e d b y th e p re s e n c e o f m icro ­
organism s in th e n o n - s t e r i l i z e d s o i l s t h a t would u t i l i z e th e a v a ila b le n i ­
tr o g e n i n b re a k in g down th e a d d i t i o n a l s u b s tr a te t h a t had b e en in c o rp o ra te d
in to th e s o i l .
I n th e s t e r i l i z e d s o i l , th e m icroorganism s sh o u ld be a t a
minimum and a s a r e s u l t , th e p la n t would have l i t t l e or no c o m p e titio n from
th e m icroorganism s f o r n itr o g e n ; c o n se q u e n tly more n itr o g e n would be a v a i l ­
a b le f o r p la n t u s e .
These r e s u l t s a re s im ila r t o th o s e o f A fanaslevC 2) who
fo u n d t h a t when n itr o g e n was added t o th e s o i l in th e f i e l d , th e amount o f
d is e a s e d b e e t s e e d lin g s was n e a r ly th e same a s in th e check p l o t s .
He s t a t e d
-5 2 -
t h a t n itr o g e n f e r t i l i z a t i o n w hich i s e x c e s siv e w ith r e s p e c t t o o th e r e s ­
s e n t i a l elem ents may p re d is p o s e young s e e d lin g s t o d i s e a s e ,
• A f te r a d ju stm e n t o f b o th th e phosphorus and n itr o g e n le v e l s in a l l
r e s id u e s in c o rp o ra te d in to s t e r i l i z e d s o i l s , th e i n t e n s i t y o f d is e a s e was
re d u c e d .
T his r e d u c tio n was g r e a t e r in th e s t e r i l i z e d s o i l t h a n . i n th e
n o n - s te r i l i z e d .
Here a g a in th e m icroorganism s were in c o m p e titio n w ith
th e b e e t s e e d lin g s f o r th e a v a ila b le n u t r i e n t s in th e n o n - s t e r i l i z e d s o i l ,
b u t th e s e amendments sh o u ld have been a v a ila b le f o r p la n t use in th e ' s t e r ­
iliz e d s o il.
The d e c re a se in d is e a s e was p o s s ib ly due t o b a la n c e d n u t r i ­
t i o n o r a g r e a t e r v ig o r o f th e p l a n t s .
S im ila r e f f e c t s o f p h o sp h ate in
r e d u c tio n o f d is e a s e w e re . o b serv ed b y 'K o tila and Coons ( 2 5 ) who were a b le
t o g r e a t l y re d u c e th e amount o f s e e d lin g d is e a s e b y grow ing s u g a r b e e ts
in o c u la te d w ith A. c o c h lio id e s i n a u to c la v e d q u a rtz -s a n d s u p p lie d w ith a
h ig h -p h o sp h a te n u t r i e n t s o l u t i o n .
F u r th e r ev id en ce o f e f f e c t s o f ,phos­
p h a te in re d u c in g r o o t r o t was p re s e n te d b y V a n te rp o o l ( 3 1 ) .
His r e s u l t s ■
in d ic a te d t h a t an in c re a s e in th e p h o s p h a te -n itro g e n r a t i o i n th e s o i l
i n h i b i t e d a Pythium r o o t r o t o f w h eat, w h ile a d e c re a se o f th e same r a t i o
s tim u la te d i t .
He c o n sid e re d t h a t an im proper b a la n c e o f a v a ila b le p h o s­
p horus and n itr o g e n in th e s o i l le a d s t o an u n b alan ced m etab o lism o f th e
w heat s e e d lin g s a t a c r i t i c a l s ta g e in t h e i r developm ent, th e r e b y p r e ­
d is p o s in g them t o fu n g a l a t t a c k .
The u se o f th e m o d ifie d C hester tu b e t o i s o l a t e s o i l f u n g i was b ased
on th e b e l i e f t h a t th e a c t i v e l y grow ing m ycelium would c o lo n iz e th e medium
-5 3 -
in th e c a p i l l a r i e s and t h i s Vould p erh ap s h e a b e t t e r in d ic a tio n o f th e
m ic ro flo ra th a n i s o l a t i o n s o b ta in e d b y o th e r m ethods.
In s o i l d ilu tio n
te c h n iq u e s , a predominance- o f heavy sp o re -fo rm e rs a re u s u a ll y o b ta in e d and
t h i s i s n o t n e c e s s a r i l y in d ic a tiv e o f th e a c ti v e grow th o f an organism in
th e s o i l .
A d isa d v a n ta g e o f th e C h e ste r tu b e method i s t h a t i t i s impos­
s i b l e t o o b ta in .a q u a n t i t a t i v e measurement o f th e m icro o rg an ism s} o th e r
th a n assum ing th e most abundant o r f a s t e s t grow ing organism s would be i s o ­
l a t e d most f r e q u e n tly .
The fu n g i t h a t were most commonly i s o l a t e d from th e s o i l in th e s e
ex p erim en ts were u sed f o r a n t i b i o t i c t e s t s in th e la b o r a to r y and in th e
g re e n h o u se .
The d ia ly s a te from e v e ry organism t e s t e d had some in h ib ito r y
e f f e c t upon th e grow th o f A. c o c h li o id e s .
T h is may have b e en a p ro d u c t o f
m etabolism from th e organism o r i t c o u ld p o s s ib ly have b e en an a l t e r a t i o n
o f th e pH w hich was a d v e rse t o th e grow th o f Aphanomyces.
When th e t e s t organism s were in o c u la te d alo n g w ith th e path o g en in
s t e r i l i z e d s o i l p la n te d t o su g ar b e e t s , th e i n t e n s i t y o f d is e a s e ran g ed
from 93 t o 100$ in f e c te d p l a n t s j how ever, in th e n o n - s t e r i l i z e d s o i l th e
d is e a s e ra n g e d from 22 t o 55$•
The in o c u la te d check in th e s t e r i l i z e d s o i l
had 100$ in f e c te d p la n ts and 53$ o f th e p la n ts were d is e a s e d in th e in o c ­
u la te d check in th e n o n - s t e r i l i z e d s o i l .
I n th e s t e r i l i z e d s o i l , i t does
n o t a p p ea r t h a t any o f th e t e s t e d organism s were a b le t o in flu e n c e th e
p a th o g e n ic ity o f A. c o c h li o id e s .
I n th e n o n - s t e r i l i z e d s o i l , th e a d d itio n
o f th r e e d i f f e r e n t f u n g i, A l t e r n a r i a , P e n ic illiu m , and Pythium , red u ced
th e amount o f d is e a s e below th e in o c u la te d check by n e a r ly 50$.
I t is
-
5i
-
p o s s ib le t h a t in th e p re se n c e o f o th e r m icroorganism s th e a n t i b i o t i c
p o t e n t i a l o f an organism i s enhanced.
P o s s ib ly th e a d d itio n o f one
p a r t i c u l a r fungus w i l l s tim u la te th e grow th o f o th er, groups o f m icro ­
organism s such a s b a c t e r i a and a c tin o m y c e te s .
in a p a r t i c u l a r environm ent
I t may be t h a t a fungus
w i l l become p a r a s i t i c upon th e p a th o g en .
These c o n s id e ra tio n s cannot be answ ered now, b u t i t i s s tr o n g ly f e l t
t h a t f u r t h e r work sh o u ld be conducted w ith th e s e organism s and a ls o
w ith o th e r groups o f s o i l m ic ro o rg an ism s.
.
+&
-r1
/
-5 5 -
i
SUMMARY
1.
The e f f e c t s o f m ature cro p r e s id u e s o f a l f a l f a , b e a n , b e e t , c o rn ,
p o ta to and w heat on s e e d lin g d is e a s e o f su g ar b e e ts cau sed b y
Aphanomyces c o c h lio id e s D re c h s. were s tu d ie d .
2.
I n g e n e r a l .no r e d u c tio n in b la c k r o o t d is e a s e was o b ta in e d b y .a d d in g
v a rio u s r e s id u e s t o s t e r i l i z e d s o i l in o c u la te d w ith A. c o c h lio id e s .
3.
W ith th e e x c e p tio n o f th e f i r s t t e s t in th e beet-am ended s o i l , th e
p e rc e n ta g e o f d is e a s e d b e e t p la n ts in n o n - s t e r i l i z e d s o i l s t o which
m ature cro p r e s id u e s had been added was low er th a n in th e in o c u la te d
ch eck .
4.
A d ju s tin g a l l r e s id u e s t o th e same le v e l' o f n itr o g e n d id n o t red u ce
th e amount o f d is e a s e o f b e e t s , b u t a l l p la n ts in th e s t e r i l i z e d
s o i l were la r g e r th a n th o s e in th e n o n - s t e r i l i z e d s o i l .
5«
A d ju s tin g a l l r e s id u e s t o th e same phosphorus and n itr o g e n le v e ls
a p p ea re d t o d e c re a se th e amount o f d is e a s e o f b e e ts in th e
s te r­
i l i z e d s o i l , b u t in th e n o n - s t e r i l i z e d s o i l t h i s d e c re a se was not
as .n o tic e a b le .
6.
F u n g i i s o l a t e d from th e s o i l b y th e m o d ified C h e ste r tu b e te c h n iq u e
were p re d o m in a n tly o f th e Fuaarium s p e c ie s ,
7.
The commonly i s o l a t e d f u n g i showed v a ry in g d eg rees o f antagonism
when in o c u la te d w ith th e pathog en in a P e t r i d is h .
When th e s e
f u n g i were in o c u la te d w ith A. c o c h lio id e s i n s t e r i l i z e d s o i l p la n te d
t o su g ar b e e t s , no a p p a re n t a n ta g o n is tic e f f e c t c o u ld be a t t r i b u t e d
t o any one organism .
-
8.
56
-
When Alterharia# P e n lc l l liu m and Pyfahlum were added t o n o n - s t e r i l i z e d ,
lm e u l a t e d s o i l , 5 0 r e d u e tio n in th e amount' o f d is e a s e o ccu rred in
com parison t o th e in o c u la te d check*
.9•
The r e s id u e a sh t e s t i s m i in c lu d e d b ecau se th e g e rm in a tio n o f b e e t
seed s was v e ry poor In a l l p o t s .
T h is was p ro b a b ly due t o th e a d d i­
t i o n Of an e x c e s s iv e q u a n tity o f S a lt t h a t was form ed in n e u tr a liz in g
th e a sh s o lu tio n *
-5 7 -
LITERATURE CITED
Ii
A fa n a s ie v , M. Mo . 19^-8s The r e l a t i o n o f s ix groups o f f u n g i to
s e e d lin g d is e a s e s o f su g ar b e e ts in M ontana« Phybo p ath o lo g y
3 8 : 205 - 212 *
2.
A fan asiev ^ Mo M. 1948* E f f e c t o f f e r t i l i z e r s on d is e a s e s and
.y ie ld o f s u g a r b e e ts p la n te d in d e p le te d s o i l . P r o c s Am.
S oc. Sug. B eet T echs 2.94-2.99•
3.
A fa n a s ie v , M. M ., and H. E . M orris* 1942* C o n tro l o f s e e d lin g
d is e a s e s o f s u g a r b e e ts in M ontana. P h y to p a th o lo g y 3 2 :4 7 7 486.
4.
A fa n a s ie v , Ms M*, and Hs E s M o rris . 1949. E f f e c t Of f e r t i l i z a ­
t i o n on th e re c o v e ry o f tr a n s p la n t e d su g ar b e e t s e e d lin g s
a f f e c t e d w ith Aphanomyces e o c h lio id e s D re c h s. in th e g re e n ­
h o u se . P h y to p a th o lo g y 39:1001-1004*
5.
A fa n a s ie v , M. M*, H. E . M o rris , and ¥ . E . C a rls o n . 1,942. The
e f f e c t o f p re c e d in g cro p s on th e amount o f s e e d lin g d is e a s e s
o f su g ar b e e t s . P r o c . Am. Soc. Sug. B eet T ech. 4 3 5 -5 3 6 .
6.
A lle n , R . J . L. 1940. The e s tim a tio n o f p h o sp h o ru s.
c h em ica l J o u r . 3 4 :858-866.
7*
B ellin g h am , R . C. 194,9* The e f f e c t o f v a rio u s s o i l amendments
and p re c e d in g cro p s on s e e d lin g d is e a s e o f su g ar b e e ts
cau sed b y Aphanomyces e o c h lio id e s D re c h s. M aster T h e sis
a t Montana S ta te C o lle g e .
8*
B u c h h o ltz , Wo F . 1944* The sequence o f in f e c tio n o f a s e e d lin g
s ta n d o f su g ar b e e ts b y Pybhium d e b aryanum and Aphanomyces
e o c h li o id e s . Phybo p ath o lo g y 34:490-4,96.
9*
B u c h h o ltz , W. F . 1,948. Aphanomyces e o c h lio id e s i n f e s t a t i o n in
i r r i g a t e d su g ar b e e t - a l f a l f a r o t a t i o n p lo ts a t N ew ell, South
D a k o ta . P h y to p a th o lo g y 38:4* ( A b s tr a c t) .
10*
Coons, G. H ., and J . E* K oti l a . 1935• In flu e n c e o f p r e c e d in g '
cro p s on dam ping-off Of su g ar b e e t s . P h y to p a th o lo g y 2 5 :1 3 .
11*
Coons, 0* H*,. and D* S te w a rt. 1927. P re v e n tio n o f s e e d lin g
d is e a s e s o f s u g a r b e e ts-. P h y to p a th o lo g y 1 7 :2 5 9 -2 9 6 .
B io ­
-
58
-
12i
Coons, G, H .; J . E . K o tila and H. W. B o c k s ta h le r . 19^2, B lack
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A s s o c ia tio n e f f e c t s o f f u n g i.
B o t. R ev.
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