RUTGERS COOPERATIVE EXTENSION AT THE NEW JERSEY AGRICULTURAL EXPERIMENT STATION
PLANT & PEST ADVISORY
LANDSCAPE, NURSERY & TURF EDITION
$1.50
MARCH 7, 2002
Think of Water from a
Plant Disease Perspective
Ann Brooks Gould, Ph.D., Plant Pathology and Margery
Daughtrey, Cornell University, Senior Extension Associate
T
he balance among the microorganisms that cause disease
(called pathogens), their host plants, and the environment
ultimately determines whether a disease will develop. The
environmental factor that has the most impact on plant disease development is moisture. Living organisms consist chiefly of water, so the uptake of
water is critical if organisms, both plant pathogens and their hosts, are to grow.
The Role of Water in Plant Disease Development
INSIDE
Think of Water from a Plant
Disease Perspective ................... 2
NJDEP Drought Information ... 2
Rutgers Lab Services ................. 2
Plant & Pest Advisory
2002 Schedule ............................. 2
Rhabdocline Needlecast
of Douglas Fir ............................. 3
DEP Changes Pesticide
Regulations ................................. 3
NOFA Announces First-Ever
Standards for Organic
Land Care .................................... 5
Nursery & Greenhouse Film
Recycling ..................................... 5
From a host perspective, too little water in the soil (drought stress)
or too much soil moisture (which leads to oxygen deprivation) places
plants under stress, and plants with water stress are more susceptible to
disease. Water is also important to facilitate movement of nutrients
from the roots to aerial plant parts, as well as sugars, made in the leaves
during photosynthesis, to the roots. Thus, any environmental condition
or disease (such as a vascular wilt or root rot) that impedes the flow of
water in the vascular system also places undue stress on the host.
Symptoms of plants with long-term water stress (at either extreme)
include leaf wilt, yellowing, scorch, or premature drop, a decline in
vigor, progressive branch dieback, and eventual death.
From a pathogen perspective, moisture extremes have a similar
impact. Although too much water in the soil deprives pathogens of
oxygen, too little water impedes pathogen survival and the infection
process. Free moisture on leaf or root surfaces is necessary for germination, penetration, and dispersal of fungal spores to new hosts.
Indeed, most pathogenic fungi grow best in a damp environment.
Powdery mildews are a notable exception, thriving in humid rather
than wet conditions.
Pathogenic fungi secrete enzymes into leaf or root tissues to
macerate, or soften up, host cells, releasing nutrients that are taken up
by the fungus as food. Free moisture is needed to help move the
enzymes out of the fungus and to let the nutrients flow back in. Some
species of fungi with very thin walls require a continuous supply of
water to prevent desiccation.
Water is also important for the infection process, which is a series
of steps that includes spore germination, penetration through the host
SEE WATER AND DISEASE ON PAGE 2
VOL. 8 NO. 1
PAGE 1
New Jersey DEP
Drought Information
New Jersey Drought Webpage
www.njdrought.org
New Jersey Drought Hotline
1-800-448-7379
Fax: 609-633-1495
3/7/02 - Drought emergency in effect
throughout entire state. No water restrictions issued. ‘Region specific’ restrictions
will be announced early next week. ❏
Rutgers Lab Services
❖ The Plant Diagnostic Laboratory
and Nematode Detection Service provides accurate and timely diagnoses of
plant problems. For sample submission
instructions and forms, visit our web site
at: http://www.rce.rutgers.edu/
plantdiagnosticlab/submissions.html.
Forms may also be obtained from your
local county Rutgers Cooperative Extension office or via fax request (732/9321270).
❖ The Rutgers Soil Testing Laboratory
performs chemical and mechanical
analyses of soils. For More Information
please write or call us: Rutgers Soil
Testing Laboratory, P.O. Box 902,
Milltown, NJ 08850, 732/932-9295, Fax:
732/932-9292 or visit us on the web at:
http://www.rce.rutgers.edu/soiltestinglab/
index.html. ❏
Plant & Pest
Advisory
2002 Schedule
T
hank you for subscribing to the
Plant & Pest Advisory. The
Landscape, Nursery & Turf edition will be
published biweekly on Thursdays for the
2002 growing season from March 7 to
August 22, with monthly issues from
September to November. ❏
PAGE
2
WATER AND DISEASE FROM PAGE 1
epidermis, and fungal growth within the plant tissues. The pathogen
can be particularly vulnerable to drying while it is in the process of
trying to infect the plant. For aerial plant pathogens, free moisture and
high relative humidity is important for infection of leaf and other
above-ground tissues (such as petals, stems, branches, or fruit). This
process requires a period of continuous leaf wetness, and this “duration
of leaf wetness” varies with the fungus. For example, spores of Venturia
inaequalis, the pathogen that causes apple scab, require 9 hours of
continuous leaf wetness to infect leaves and fruit. It stands to reason,
therefore, that irrigation strategy and amount of natural rainfall would
have a great impact on the development of this disease.
For fungi that attack roots, free moisture is also required for the
infection process. In addition, water in soil pores is needed for the motile
spores (called zoospores) produced by a group of common soil pathogens
(the water molds) to swim toward healthy roots. Finally, moisture, in the
form of rain, splashing, and running water, is important for the dispersal of
spores of all kinds of fungi to the roots or foliage of new hosts.
Managing Water in the Nursery: The clue is to think like
a plant and a spore!
Moisture management in the nursery is important from both a plant
health and a pathogen point of view. Too much or too little moisture
during production can have equally devastating results. Some points to
keep in mind include:
● As a rule, avoid prolonged periods of leaf wetness. If using overhead
irrigation, water to minimize the length of time foliage stays wet.
Water during early morning hours or water during warmer, breezier
periods when rapid drying is likely to occur. Consider using drip
irrigation or aimed microemitters that do not place moisture on foliar
surfaces.
● Avoid excess moisture in potting mix. In addition to its harmful
effects on the host, too much water promotes the activity of both
water mold (e.g., Pythium and Phytophthora) and non-water mold
(e.g., Rhizoctonia, Fusarium, and Thielaviopsis) soil pathogenic fungi.
Excess water is also conducive to the growth of anaerobic bacteria
which produce by-products that are toxic to plant roots.
● Use a balanced potting mix with properties of aeration and moisture
retention that are appropriate to the size of the container. In mixes
that do not drain well, a perched water table is created at the bottom
of the container, which encourages the growth of microorganisms
and pathogens and deprives roots of oxygen.
● When using hydrophobic components in mix, such as ground bark or
peat, avoid extreme drying of the pot. Rewetting such mixes is
difficult; water from overhead sprinklers simply channels around the
rootball and drains away.
● Some woody ornamentals are prone to edema. Edema, or corky,
blister-like outgrowths on the lower surface of leaves, occurs during
cloudy periods with abundant moisture. In such conditions, when
more water is supplied to leaf tissues than is lost during transpiration,
the cells that line leaf stomates (where gas exchange occurs) become
too full and burst. Ornamentals especially prone to edema are
Camellia, Hedera, Hibiscus, Ligustrum, Pittosporum, and Taxus.
● Diseases (particularly Phytophthora root rot) can be spread when
pathogen-infested pond water is used for irrigation. Avoid using
pond water if possible, and do not allow runoff water from growing
areas to drain directly into irrigation ponds. ❏
VOL. 8 NO. 1
DEP Changes
Pesticide Regulations
Rhabdocline Needlecast
of Douglas Fir
Ann Brooks Gould, Ph.D., Plant Pathology
W
e’ve received a number of reports the past
few weeks on the incidence of Rhabdocline
needle cast of Douglas fir in Christmas tree plantations.
The weather during the infection period in many
locations last year was ideal for disease development.
This disease is of great concern to Christmas tree
growers in New Jersey, and with good reason. Severely
affected trees lose a large portion of their needles, and
this can represent a significant loss to the grower,
especially on trees almost ready for sale.
To diagnose Rhabdocline needlecast, look for redbrown spots surrounded by green tissue on last year’s
growth. In many plantations, this symptom is evident
now. A week or two before budbreak, orange fruiting
bodies develop on the lower surface of affected
needles. Once the fruiting bodies are mature, they
rupture and release abundant spores during wet
weather. Spores, which are blown by wind and rain to
nearby trees, infect expanding buds. Symptoms on
newly infected needles do not appear until the following fall or winter. Rhabdocline needlecast is influenced
by high humidity, so lower branches, shaded branches,
or branches on the northeast side of the tree are more
severely affected.
Trees with the disease can serve as a source of
inoculum for new growth this season, so it is important
to use aggressive control measures in blocks where the
disease has occurred. For best results, remove old and
severely infected trees now. Branches on trees that are
less severely infected (less than 30% of branches
affected) should also be pruned now during dry
weather. If possible, a burning permit should be
obtained so that infected tissue can be incinerated.
Chlorothalonil (Bravo or Daconil) is labeled for
control of Rhabdocline needlecast. Begin sprays when
the first 10% of the trees in the planting first break bud
(or the candles are about 1/2 inch long). The second
spray goes on one week later, and the third spray goes
on two weeks after the second spray. A fourth spray
three weeks later may be necessary if rainy spring
weather persists. Add a spreader sticker to enhance
coverage. Other compounds labeled for control
include benomyl (apply two times at 4-week intervals),
Kocide (apply at 1- to 2-week intervals), Spectro (apply
at 2- to 3-week intervals), or mancozeb (Junction).
Refer to label for timing and rates. For all fungicides,
thorough coverage is essential. For further information
on Rhabdocline needlecast, refer to Rutgers Cooperative
Extension fact sheet FS183, available through your
county extension office. ❏
VOL. 8 NO. 1
George Hamilton, Ph.D., Pest Management
I
n November of 2001, the New Jersey Department
of Environmental Protection put into place several
changes to the New Jersey Pesticide Control Act. In this
issue we will cover the changes that affect who must
have a private applicators license to apply pesticides;
how a commercial pesticide applicator license is
obtained; and who must have a commercial pesticide
operator registration (now referred to as a commercial
pesticide operator license) to apply pesticides and how
that license is obtained.
Upcoming issues will cover changes regarding
areawide notifcation, service vehicles, record keeping,
storage areas, outdoor notification, and schools.
Changes to Definition of Private Pesticide
Applicator
In the past, only those farmers who either applied or
supervised the application of restricted use pesticides
needed to have a pesticide license. The new change
now requires that farmers who apply or supervise the
use of any pesticide, general or restricted use, must now
have a private applicator license. The only exceptions
are as follows:
1. Farmers who apply pesticides under the supervision
of a licensed private applicator who is employed by
the same farm at the same physical location, or
2. Farmers who already have a commercial applicators
license with the proper category certification(s), or
3. Farmers who apply general use pesticides to produce an agricultural commodity worth less than
$2,500 annually on land that they either own or
rent, or
4. Farmers who apply only “minimum risk” pesticides
as defined in N.J.A.C. 7:30-2.1(m)5, or
5. Farmers who have experience in using agricultural
pesticides to produce an agricultural commodity and
only use general use products. This final exemption
expires November 19, 2003.
This new change means that even if you are applying or supervising the application of products such as
carbaryl, diazinon or Bacillus thuringiensis on agricultural crops you must have a private applicators license.
The implications of this change means that several
grower groups, such x-mas tree growers, vineyardists and
organic growers, will now have to obtain licenses if they
apply or supervise the use of EPA registered pesticides.
If you need to obtain a private applicators license
because of the new requirement, please be aware that
the process for getting a license has not changed. The
first step is to obtain the “Private Applicator Manual”
SEE PRIVATE APPLICATOR ON PAGE 4
PAGE 3
PRIVATE APPLICATOR FROM PAGE 3
and informational sheet explaining the procedure for
signing up to take the exam from your local County
Cooperative Extension office. Once you have studied
the manual and are ready to take the exam follow the
procedures outlined in the pamphlet to register for the
exam.
Changes to Obtain Commercial Pesticide
Applicators License
In the past, a commercial pesticide applicator
license was obtained by:
● acquiring the CORE pesticide applicator training
manual, and the appropriate Pesticide Applicator
Category manual(s) for the type(s) of work you would
do, and
● studying the manuals on your own, and
● registering to take the CORE and Category(s) exams
needed for the type of work you would be doing.
Once you passed the CORE and Category exams
and paid the license fee, you became a licensed commercial pesticide applicator.
Today, the process has been slightly changed. In
addition to the items listed above, to be eligible to take
the CORE exam, a prospective commercial pesticide
applicator must complete a DEP approved basic pesticide training course. Once the course is completed the
applicant can register and take the CORE exam.
Once you have passed the CORE exam and prior to
taking the required Category(s) exams the applicant must
complete a minimum of 40 hours of “on the job”
training sufficient to competently perform the functions
of any applications the applicant may become involved
with. During this period the applicant must be instructed in the recognition, biology and infestation signs
of the pests to be controlled and perform or observe a
minimum number of applications under the direct
supervision of a licensed commercial pesticide applicator for each category the person will be licensed. The
number of applications required varies depending on
the type of work being performed. The only deviations
from this process are as follows:
● Category 10 is exempt from “on-the-job” training
requirements since training is required related to the
specific category for which Category 10 applications
will be made.
● Category 11 requires “on-the-job” training in aerial
pest control only and is exempt from the “on-the-job”
training requirements for other categories.
If 40 hours of “on-the-job” training is deemed unavailable by DEP the Department may allow:
● the substitution of an internship from an approved
trainer, company or school and successful completion
of an approved category training course that covers
the recognition, biology and infestation signs of the
pests to be controlled, or
● submission
of an affidavit attesting to proof of one
year of work experience in the category desired.
If 40 hours of “on-the-job” training or an internship
is deemed unavailable by DEP the Department may
allow successful completion of a DEP approved correspondence course or on-line interactive computer
course to satisfy the training requirements.
Once the “on-the-job” training is completed, the
applicant can register to take the required category
exam(s) by submitting the required application form
complete with proof of successful completion of the
“on-the-job” training.
Changes to Commercial Pesticide Operator
Registrations
In the past, a commercial pesticide operator license
was needed to apply general or restricted use pesticides
unless:
● the person was a licensed commercial pesticide
applicator, or
● the person worked under the direct supervision of a
licensed commercial pesticide applicator that was
always present at the application site.
Today, in addition to the exclusions listed above, an
operator license is not needed if the person is:
● applying pesticides denoted as “minimum risk” by EPA
under 40 CFR 152, or
● exempted under N.J.S.A. 13:1F-1a. Examples of this
exception includes municipal or county inspectors
who use only general use pesticide as flushing agents,
such as pyrethrum sprays, to check for insect infestations during the normal course of their job.
DEP has also changed the process for obtaining a
commercial operator license. In the past, a form was
filled out by the applicant and his licensed supervisor
that certified the applicant had had the necessary
training to become a commercial pesticide operator.
Today, anyone who wishes to become licensed as a
commercial pesticide operator and has never been so
before must:
1. complete a DEP approved commercial pesticide
operator training course, and
2. complete a minimum of 40 hours of “on the job”
training sufficient to allow the operator to competently perform the functions of a commercial pesticide operator. During this period the operator must
perform or observe a minimum number of applications under the direct supervision of a licensed
commercial pesticide applicator. The number of
applications required varies depending on the type of
work being performed.
Once the approved commercial pesticide operator
training course is completed, the operator can apply to
DEP for a commercial pesticide operator license by
submitting a completed Operator Application Form to
DEP. Applications for commercial pesticide operator
SEE COMMERCIAL OPERATOR ON PAGE 5
PAGE
4
VOL. 8 NO. 1
NOFA Announces First-Ever
Standards for Organic Land Care
October, 2001 Press Release
o help meet the growing demand for organic lawn and
yard care, the Massachusetts and Connecticut Chapters
of the Northeast Organic Farming Association (NOFA) have
created Standards for Organic Land Care: Practices for Design
and Maintenance of Ecological Landscapes. The NOFA Standards are the first of their kind, and are expected to become a
model for organic land care throughout the United States. The
NOFA Organic Land Care Committee, consisting of land care
professionals, scientists, educators, and activists, worked for
two years to write the Standards. According to Kim Stoner,
Ph.D., the chair of the Committee, “these Standards are just as
rigorous as those set for organic agriculture by Connecticut and
Massachusetts NOFA chapters, but they have also been
adapted to address the special issues and challenges of designing and maintaining landscapes.”
The 60-page Standards spell out recommended, allowed,
and prohibited practices to conform to organic standards. The
Committee developed a 30-hour course to certify land care
professionals in organic landscape management. The graduates
of this course will make up the NOFA list of accredited organic
land care professionals. Programs for the public are being
planned for spring 2002 to highlight the benefits of organic
land care methods and materials. Also, a survey will soon be
underway to identify which garden centers and chain stores in
Massachusetts offer organic soil amendments and materials for
sale to consumers. The survey results and list of accredited
professionals will be included in the upcoming “A Citizen’s
Guide to Organic Land Care”.
The Organic Land Care Committee’s mission is: education
of land care professionals and concerned citizens in the
practice of organic land care, with the goals of maintaining soil
health, eliminating synthetic pesticide and synthetic fertilize
use, increasing landscape diversity, and improving the health
and well-being of the people and web of life in our care.
Printed copies of the Standards are now available for $20 each
from NOFA/Mass, 411 Sheldon Road, Barre, MA 01005; (978)
355-2853; www.massorganic.org.
For more information about the Organic Land Care Standards or to be notified of courses and publications, please
contact Marilyn Castriotta, Organic Land Care Program Administrator, at (781) 646-6322 or castriotta@aol.com.
To subscribe to the gnf, send an e-mail to
majordomo@umassextension.org. In the body of the message,
type: subscribe gnf. Leave the subject field blank. To
unsubscribe, send an e-mail to
majordomo@umassextension.org. In the body of the message,
type: unsubscribe gnf. Leave the subject field blank.
Submitted by Jim Willmott, Camden County Agricultural
Agent. ❏
T
VOL. 8 NO. 1
Nursery & Greenhouse
Film Recycling
N
ew Jersey’s 2002 nursery and greenhouse film collection and recycle
program will be held for the 6th year. This year’s
program has been expanded to include collection from out-of-state growers.
Participating growers can take film to one of
three collection sites (see below). Each film
collection site has specific procedures that must
be followed when film is transported to the site,
as well as it’s own collection dates and tipping
fees. Contact the sites to determine the particular procedure that must be followed.
For additional information on the nursery &
greenhouse film recycling program, growers can
contact the New Jersey Nursery & Landscape
Association at 609-291-7070 or Karen Kritz at
the New Jersey Department of Agriculture at
609-984-2506 or e-mail
Karen.Kritz@ag.state.nj.us.
The following are the collection sites:
Cumberland County Solid Waste Complex
Deerfield, NJ
856-825-3700
Contact: Dennis DeMatte, Jr.
East Coast Recycling Associates
Millville, NJ
856-327-888
Contact: George Glenn III
Burlington County Occupational Training Center
Mt. Holly, NJ
609-267-6889 ext. 160
Contact: Kevin Carducci or Stephen Paulo
COMMERCIAL OPERATOR FROM PAGE 4
licenses can be obtained by contacting the DEP
Pesticide Control Program at 609-984-6601 or
on the internet at http://www.state.nj.us/dep/
enforcement/pcp/. Once the application is
submitted the applicant should undergo the
“on-the-job” part of the process. Remember that
the supervising commercial pesticide applicator
is responsible for keeping and maintaining
records of the ”on-the-job” training for each
commercial pesticide operator under his/her
supervision.❏
PAGE 5
Plant & Pest Advisory
18 College Farm Road
Cook College
New Brunswick, N.J. 08901-8551
Rutgers Cooperative Extension - NJAES
U.S. DEPARTMENT OF AGRICULTURE
Rutgers -The State University of New Jersey
PLANT & PEST ADVISORY LANDSCAPE NURSERY & TURF EDITION CONTRIBUTORS
RCE Specialists and Staff
Bruce B. Clarke, Ph.D., Turf Pathology
Ann B. Gould, Ph.D., Ornamentals Plant Pathology
Steven Hart, Ph.D., Weed Science
Joseph R. Heckman, Ph.D., Soil Fertility
Albrecht Koppenhofer, Ph.D., Turfgrass Entomology
James A. Murphy, Ph.D., Turf Management
George J. Wulster, Ph.D., Floriculture
Richard J. Buckley, Coordinator, Plant Diagnostic Laboratory
RCE County Agricultural Agents and Program Associates
Atlantic, Charlene H. Costaris (609-625-0056)
Bergen, Joel Flagler (201-599-6162)
Burlington, Raymond J. Samulis (609-265-5050)
Camden, James Willmott (856-566-2900)
Cumberland, James R. Johnson (856-451-2800)
Essex, Jan Zienteck, Program Coordinator (973-353-5958)
Gloucester, Jerome L. Frecon (856-881-4191)
Hunterdon, Winfred P. Cowgill, Jr. (908-788-1338)
Mercer, Annette Capp, Program Associate (609-989-6830)
Middlesex, William T. Hlubik (732-745-3443)
Monmouth, Richard G. Obal (732-431-7261)
Morris, Pedro Perdomo (973-285-8307)
Ocean, Steven Rettke, Program Associate IPM (732-349-1246)
Somerset, Nick Polanin (908-526-6293)
Union, Madeline Flahive-DiNardo (908-654-9854)
Warren, William H. Tietjen (908-475-6505)
Newsletter Production
Jack Rabin, Associate Director for Farm Services, NJAES
Cindy Rovins, Crop Management Communications Editor
Rutgers Cooperative Extension (RCE)
provides information and educational
services to all people without regard to sex,
race, color, national origin, disability, or age.
RCE is an Equal Opportunity Employer.
Pesticide User Responsibility: Use pesticides safely and follow instructions on
labels. The pesticide user is reponsible for
proper use, storage and disposal, residues
on crops, and damage caused by drift. For
specific labels, special local-needs label
24(c) registration, or section 18 exemption,
contact RCE in your County.
Use of Trade Names: No discrimination or
endorsement is intended in the use of trade
names in this publication. In some instances a compound may be sold under
different trade names and may vary as to
label clearances.
Reproduction of Articles: RCE invites
reproduction of individual articles, source
cited with complete article name, author
name, followed by Rutgers Cooperative
Extension, Plant & Pest Advisory Newsletter.
For back issues, visit our web site at: www.rce.rutgers.edu/pubs/plantandpestadvisory