The Georgia Agricultural Experiment Stations College of Agricultural and Environmental Sciences The University of Georgia – Griffin Campus Research Report Number 715 July 2008 SMALL GRAIN UPDATES VARIETY RELEASES Jerry W. Johnson, Department of Crop and Soil Sciences, Griffin Campus, Griffin, GA 30223 AGS 2020 is an early maturing, white chaffed, medium height line. It was derived from the cross, GA 88151/ Hickory//AGS 2000. Its maturity is 3 days earlier than AGS 2000. It is moderately resistant to current biotypes of Hessian fly in Georgia and is resistant to races of leaf rust and stripe rust in the southeast U.S. It is also resistant to soil­borne mosaic virus and powdery mildew. Oglethorpe is a medium maturing, white chaffed, medium height line. It was derived from the cross, GA881130 / Coker 9134. The pedigree of GA 881130 is KSH8998 / FR 81­10 // Gore. Its maturity is similar to AGS 2000. It is resistant to current biotypes of Hessian fly in Georgia including biotype L and is resistant to races of leaf rust and stripe rust. It is also resistant to soil­borne mosaic virus and susceptible to powdery mildew. AGS 2026 is a medium maturing, white chaffed, medium height line. It was derived from the cross, GA881130 / Coker 9134. The pedigree of GA 881130 is KSH8998 / FR 81­10 // Gore. Its maturity is similar to AGS 2000. It is resistant to current biotypes of Hessian fly in Georgia including biotype L and is resistant to races of leaf rust and stripe rust. It is also resistant to soil­borne mosaic virus and susceptible to powdery mildew. Horizon LA976 is a new winter oat variety co­developed by the Louisiana State University Agricultural Center and University of Florida, and released under SUNGRAINS. Horizon LA976 has excellent grain and forage yield along with high test weight and excellent crown and stem rust resistance. It is well adapted to the Southeastern US and will be an excellent dual purpose and conservation tillage oat. Horizon LA976 will be marketed exclusively by Plantation Seeds. Wheat releases by private companies for production in Georgia include: Coker 9700 and PIO 26R87.
DISEASE John D. Youmans and James W. Buck, Department of Plant Pathology, Griffin Campus, Griffin, GA 30223­1797 The southwestern part of the state had soil borne mosaic virus issues due to moist and cooler soil conditions experienced in January through March. Early powdery mildew disease pressure was again highest at Tifton and southwest Georgia. The dry weather ultimately held powdery mildew in check. Some growers chose to spray earlier in the season for disease control. Stripe rust was observed at Plains, Griffin and Calhoun where plots were artificially inoculated but in general no widespread epidemics were observed in the state. Early information from CIMMYT this year indicates that there is a new race of stripe rust that has defeated the YR 17 gene. This means that many current varieties with recognized resistance could be compromised. It will remain to be seen how quickly the new race of stripe rust spreads across the southeast. This year moderate amounts of Barley Yellow Dwarf Virus (BYDV) were observed across the state, with higher infection levels noted at Calhoun. Griffin, Plains, and Tifton had moderate BYDV pressure. Yields were affected but the extent is difficult to estimate. Stagonospora leaf and glume blotch was at fairly low levels across the state again due to the drier weather conditions observed. Leaf rust again was late and suppressed by the cooler and drier spring. Leaf rust did increase late in the season but did not affect yields. Oat crown rust was observed at Tifton on susceptible varieties. In somewhat of an unusual circumstance, stem rust was found both at Plains and at Griffin. The ARS rust lab in Minnesota confirmed that it was stem rust and that that it was not related to Ug 99. This was observed very late in the year at or near harvest and was not a factor in yield loss. Overall yields were good statewide, with the better yields in the upper coastal plain. This in spite the low rainfall observed.
INSECTS G. David Buntin, Department of Entomology, Griffin Campus, Griffin, Georgia 30223­1797. The variety test was planted in the fall of 2007 at the Southwest Branch Experiment Station near Plains and was sampled for Hessian fly, Mayetiola destructor, infestations in mid­February, 2008. Wheat entries also were evaluated at the Bledsoe Research farm near Griffin in late April. Results are shown in the next table. Several wheat varieties showed good levels of Hessian fly resistance at Plains including AGS 2000 (fair), AGS 2010, AGS 2026, AGS 2060, Jamestown, Pioneer brands 26R38 and 26R61, NK­Coker 9152, USG 3592, SS 8308 (fair), SS 8641, Vigoro Oglethorpe, and a number of experimental lines. 'Roberts’ and ‘Fleming’ contain resistance genes but are susceptible in Georgia and will not stand up to a heavy infestation. Varieties with good resistance in southern GA may not be resistant in northern GA because of the presence of biotype L in northern GA. The only currently available varieties with biotype L resistance are AGS 2010, AGS 2026, and Vigoro Oglethorpe. Rye and oats also are good Hessian­fly resistant alternatives to wheat for forage production, because rye is highly resistant and oats are immune to the insect. High commodity prices before planting encouraged increased plantings of wheat over the previous year. Short seed supply resulted in a greater proportion of Hessian fly­susceptible varieties being planted. Moderate to severe Hessian fly damage was observed in some fields planted with susceptible varieties. Warm weather encouraged aphid populations in the fall months throughout the state. Aphids caused direct injury to wheat and also transmitted barley yellow dwarf virus (BYDV). Nevertheless, BYDV infection generally was not severe throughout most of the state. Although the level of expression of symptoms varies between varieties, no varieties are truly resistant or tolerant of BYDV infection. Systemic insecticide seed treatments and properly timed foliar applications of insecticides can reduce aphid numbers and minimize BYDV incidence. Consult your local county extension agent and 2008 Georgia Pest Management Handbook for a list of recommended insecticides and for management practices for these and other insect pests of small grains.
Hessian fly infestations in wheat entries in 2007-2008
State Small Grain Variety Tests at
Plains and Griffin, Georgia
Entry name
Plains
% infested No. /stem
Griffin
% infested No. /stem
SS 520
GA 00034-7A17
SS 8404
NK-Coker 9700
GA 02603 CT-7
37.7*
30.8*
28.3*
28.3*
28.2*
0.66*
0.53*
0.48*
0.50*
0.59*
22.5*
10.0*
10.0*
2.5
17.5*
0.28
0.15
0.10
0.05
0.25
Chesapeake
D03-9804
Roberts
USG 3295
SSMPV57
26.3*
25.0*
24.5*
24.5*
24.1*
0.53*
0.47*
0.51*
0.50*
0.46*
22.5*
15.0*
7.5*
5.0
7.5*
0.32*
0.18
0.10
0.05
0.08
GA 00190-7A14
GA 991109-6E8
USG 3725
Pioneer Brand 26R87
GA 001492-7E9
24.0*
24.0*
23.8*
23.0*
23.0*
0.62*
0.51*
0.50*
0.41*
0.47*
7.5*
17.5*
32.5*
27.5*
5.0
0.13
0.28
0.75*
0.48*
0.05
Dominion
LA 98214D-14-1-2-B
Progeny 117
AGS 2031
AGS 2020
22.5*
22.1*
21.4*
20.9*
20.2*
0.50*
0.35*
0.40*
0.39*
0.38*
20.0*
15.0*
15.0*
25.0*
21.3*
0.28
0.20
0.25
0.40*
0.48*
AgriPro Panola
NC 03-6228
LA99005UC-31-3-C
GA 991227-6A33
VA-01W-205
20.0*
19.8*
19.2*
19.1*
18.7*
0.39*
0.37*
0.31*
0.32*
0.38*
15.0*
40.0*
10.0*
2.5
37.5*
0.35*
0.58*
0.10
0.03
0.70*
LA 01140D-70
GA 001170-7E26
Progeny 185
GA 981131-7E33
McIntosh
17.6*
17.1*
17.0*
16.9*
16.5*
0.35*
0.32*
0.35*
0.49*
0.33*
0
10.0*
27.5*
5.0
2.5
0
0.20
0.33*
0.10
0.05
NK-Coker 9553
Fleming
Sungold
Progeny 166
AGS 2055
15.9*
15.6*
15.4*
13.1*
12.2*
0.24*
0.23*
0.24*
0.21*
0.21*
5.0
2.5
77.5*
22.5*
5.0
0.15
0.05
1.63*
0.40*
0.08
AGS 2000
Progeny 127
Magnolia
Jamestowna
GA 991371-6E12
11.6*
11.3*
11.0*
7.2*
4.9
0.22*
0.18
0.16
0.13
0.08
2.5
35.0*
2.5
10.0*
20.0*
0.03
0.48*
0.03
0.18
0.63*
4.8
4.3
4.1
3.3
2.5
0.10
0.06
0.07
0.07
0.07
7.5*
0
5.0
7.5*
12.5*
0.10
0
0.08
0.13
0.25
GA 00138-7A6
SS 8308
USG 3209a
GA 031238-DH7-7E34
Progeny 122
Hessian fly infestations in wheat entries in 2007-2008
Georgia State Small Grain Variety Tests at
Plains and Griffin (Continued)
Entry name
Plains
% infested No. /stem
Griffin
% infested No. /stem
Progeny 145
GA 031238-DH7-7A28
GA 011264-7EB
AGS 2010b
Pioneer Brand 26R31 a
2.3
1.9
1.9
1.8
1.3
0.04
0.03
0.02
0.04
0.01
20.0*
2.5
0
0
12.5*
0.38*
0.13
0
0
0.18
SS 8641
USG 3592a
AGS 2060
LA 01138D-55
GA 981622-5E35
1.3
0.7
0.7
0.6
0.6
0.01
0.01
0.01
0.01
0.01
2.5
12.5*
0
7.5*
5.0
0.05
0.13
0
0.13
0.05
GA 981621-5E34
Pioneer Brand 26R12 a
GA 001169-7E15
GA 991371-6E13
GA 991209-6E33
0.6
0
0
0
0
0.01
0
0
0
0
2.5
7.5*
10.0*
10.0*
2.5
0.03
0.10
0.25
0.23
0.03
0
0
0
0
0
0
0
0
0
0
2.5
0
0
0
0
0.03
0
0
0
0
11.86
0.0001
0.19
6.39
0.0001
3.4
0.0001
0.30
4.12
0.0001
GA 991336-6E9
Pioneer Brand 26R61 b
AGS 2026b
GA 961567-4A35
Vigoro Oglethorpe b (GA 951231-4E25)
LSD(0.10)
F
P
* Significantly different than zero (P <0.1); % infested data arcsine-square-root transformed
before analysis.
a. Moderately susceptible in previous trials.
b. Contains resistance to Hessian fly biotype L.