Vegetable Press 

Vol. 01 No. 6
June 6, 2001

Organic Agriculture Conference

Dr. Rick Snyder
Vegetable Specialist

The Second Annual ACEP Organic Agriculture Conference will be held Tuesday, June 19, at the Duncan Gray Conference Center in Canton, MS.

Registration is from 9 to 10, General Assembly is at 10, and the actual program begins at 10:30 a.m.

The program includes workshops on production and marketing of organic farm products, tour of the medicinal herb project, and the first statewide meeting of the Mississippi Organic Growers' Association.

Registration is $25 in advance or $35 at the door, and includes an organic lunch.

To get to the conference center from downtown Canton, take U.S. 51 north for 10 miles, and turn left on Way Road. The center is on the right about 1 mile down the road. It is located north of exit 124 from I-55. The phone number of the conference center is 601-859-1556.

If you need information or a ride, call your Alcorn Ag Agent. Some Alcorn Ag Agents will have Alcorn State University vans to provide transportation to the conference. Or call Ken Rogers at 601-634-4816 or send email to krogers@lorman.alcorn.edu

Sustainable Vegetable Field Day

Dr. Rick Snyder
Vegetable Specialist

Wayne Gramelspacher, near Vaughan MS, will host a farm field day, Saturday, June 23, from 8:30 a.m. until 12 noon. Attendees will learn about soil nutrition, organic matter, sampling, and variability. Rotation, cover crops, and farm planning for small growers will also be discussed.

The speakers' program, at 9:00, will feature Mr. Gramelspacher, Yazoo Co. Extension Agent Tim Pepper, Alcorn Extension Specialist Ken Rogers, and MAFES Truck Crops Branch Research Scientist Dr. Bill Evans.

Attendees can walk the fields and will have a chance to visit with the speakers throughout the morning. The farm is an alternatively managed 1.5 acre vegetable farm, emphasizing small volumes of many crops produced with minimal off-farm inputs.

This field day is funded as part of a producer research grant from the USDA Sustainable Agriculture Research and Education (SARE) program.

The farm is located off of Highway 16, 5 miles west of I-55 in Yazoo County. Signs to the field day will be posted on Hwy 16. For more information, contact Tim Pepper, County Ag Agent, at 601-746-2453, or send email to timp@ext.msstate.edu .

Monitor 4 Insecticide Cleared for Thrips Control on Field Tomatoes

Dr. J. Pat Harris
Extension Entomologist

Mississippi Division of Plant Industry has approved a special local need registration for Monitor Insecticide from Bayer Chemical Company for thrips control on fresh field tomatoes.

It should be used at 1_ to 2 pints in 25 gallons of water per acre by ground equipment, or 5 to 10 gallons of water by air. Spray at intervals of 7 to 10 days as needed. A total of 5 applications may be made per crop season. Do not apply within 7 days of harvest. This is a good pest management tool to alternate with Spintor for control of thrips.

Monitor 4 is also labeled for control of aphids, beet armyworms, black cutworms, fruitworms, hornworms, leafminers, stink bugs, and variegated cutworms.

Avaunt Cleared for Field Vegetable Use

Dr. J. Pat Harris
Extension Entomologist

DuPont Chemical Company has announced the use of Avaunt (Indoxacarb) for insect control on field vegetables. This product is a water dispersible granule that can be applied as a foliar spray to control several insects. It is cleared only for commercial and farm plantings and will fit well into an Integrated Pest Management (IPM) program.

Avant is cleared on broccoli, cabbage (tight headed varieties only), cauliflower, sweet corn, lettuce (head and leaf varieties), pepper (bell and non-bell), and tomatoes.

It controls primarily caterpillars including beet armyworms, diamondback moth, cabbage looper, imported cabbageworm, fall armyworm, European corn borer, corn earworm, tomato fruitworm, southern armyworm, tomato pinworm, and hornworm.

Rates range from 0.045 to 0.065 pound active ingredient (AI) per acre. Time allowed between last application and harvest is three days on vegetables. See label for specific rates and precautions.

Proclaim Labeled for Some Field Vegetables

Dr. J. Pat Harris
Extension Entomologist

Novartis Chemical Company has a product called Proclaim (Emamectin benzoate) labeled for control of certain lepidopteran (worm) species in head and stem Brassica vegetables, celery, and head lettuce.

It is a selective insecticide that must be ingested by worms to be most effective. Affected worms become paralyzed and stop feeding shortly after ingesting Proclaim and thus cease causing plant damage. Worms die in 2 to 4 days.

Head and stem vegetables include cabbage, broccoli, cauliflower, brussels sprouts, chinese cabbage, chinese broccoli, cavalo broccoli, chinese mustard, cabbage, and kohlrabi. For control of beet armyworm, cabbage webworm, corn earworm, cross-striped cabbageworm, diamondback moth, fall armyworm, and imported cabbageworm, use 2.4 to 4.8 oz. per acre. For soybean looper and cabbage looper, use 3.2 to 4.8 oz. per acre. The rates are the same for those pests attacking head lettuce and celery. See label for complete details. Proclaim is a restricted use pesticide.

Tomato Yellow Leaf Curl Virus:
First Observation In Mississippi

Dr. David M. Ingram, Extension Plant Pathologist
Dr. Alan Henn, Extension Plant Pathologist
M.V. Patel, Extension Plant Pathologist
Dr. Pat Harris, Extension Entomologist
Andy Milling, IPM Technician

Recently a greenhouse tomato producer in Newton, County, Mississippi contacted Mississippi State University Extension Specialists concerning tomato plants with chlorotic leaves in the terminal. Initially, this was thought to be an environmental problem with incompletely burned heater gases causing the observed symptoms. However, several weeks later, more plants began to show up with similar symptoms. Somewhere between 70-100 plants were removed from the greenhouse and destroyed.

Extension Plant Pathology Specialists visited the greenhouse on the second occasion and observed more severe interveinal chlorosis and upward cupping of leaves in the top of plants. Symptomatic plants were generally located in a couple of bays at the west end of the greenhouse range. The symptoms observed were consistent with those caused by a virus. Samples were collected and sent to a virology diagnostics service in Indiana. The lab was instructed to conduct a comprehensive scan for the more common tomato viruses (approximately 12). Results from the lab came back positive for a whitefly-transmitted Gemini Virus. Tomato Yellow Leaf Curl (TYLCV) and Tomato Mottle Viruses are in this group. Further investigation revealed that the grower had minor problems with whiteflies during the month of December and January, but populations were not considered destructive.

Additional samples were collected and sent to a diagnostics lab in Florida for further determination of the exact virus responsible for the observed symptoms. Two tests were conducted (1) inclusion bodies and (2) Polymerase Chain Reaction (PCR). Inclusion bodies are tests that take tissue samples and subject them to specific stains that attach to virus-induced particles inside the cells. The virus particles can then be observed directly with light microscopy. Each inclusion body has a particular size, shape, location, and staining characteristics. A trained diagnostician can identify the virus group, or in many cases, such as Tomato Yellow Leaf Curl, the specific virus, using this test. The PCR test is a more complicated chemical test that matches a known unique part of the Tomato Yellow Leaf Curl Virus nucleic acid to unknowns. Each of these tests conducted in the Florida lab came back positive for TOMATO YELLOW LEAF CURL VIRUS.

This is the first report of this virus disease in Mississippi. The virus has been reported in Florida, Georgia, and southern Louisiana in field tomatoes. The source of the virus for the Mississippi infections is not known at this time. It may be possible that white flies carried in a shipment of plant material from one of the regions mentioned above "jumped" ship on the interstate, since this greenhouse operation is within a few hundred yards of a major highway. This fact will probably never be determined.

This is a destructive disease of field tomatoes, with reports from Louisiana already this spring of complete devastation to entire fields. The virus is transmitted by the silverleaf whitefly. Whiteflies can acquire the virus from infected plants after feeding for 15-30 minutes. The larvae can acquire the virus but only adults can transmit the virus. The virus is not passed from the adult to its progeny. The whiteflies can remain infective for about 10-12 days. Symptoms usually develop in about 2-3 weeks. The virus is not transmitted in seeds of tomato.

Symptoms observed in the Mississippi greenhouse tomato operation were generally more mild than those reported to occur in field tomatoes. Mild to severe interveinal chlorosis and upward cupping of leaves were the predominant symptoms observed in terminals of greenhouse tomatoes. No symptoms have been observed on fruit in greenhouse tomatoes, and flowering and yield do not appear to be affected based on our observations at this time. Field tomatoes are reported to have leaves with chlorotic margins that are smaller, cupped, thick, and rubbery. Flowers are reported to abscise resulting in no fruit production.

Control of TYLCV is very difficult. Control of viruliferous whiteflies is the only method of preventing spread of this disease. Insecticides labeled for use in greenhouse tomatoes are limited to just a few compounds. More choices are available for field tomatoes. For information on insecticides that are labeled for whitefly control refer to Extension Publication 1861 (for greenhouse tomatoes) and Extension Publication 554 (for commercial field tomatoes).

Recommendations for control from Florida are:

Keep whitefly populations low especially in the first half of the season.

Use Admire in transplants (field tomatoes only) as soon as possible.

Use chemical control throughout the growing season.

Delay plantings of fall tomatoes.

Rogue infected plants as soon as symptoms are visible.

Place infected plants in plastic bags and tie shut to prevent spread of whiteflies.

Plow under fields immediately after harvest.

Use UV-reflective mulches to reduce landing of whiteflies.

Use whitefly and virus-free transplants.

Make sure greenhouses are sealed as tightly as possible to prevent entry of whiteflies.

MEMO

TO: Vegetable and Fruit Growers
FROM: Dr. Richard G. Snyder, Vegetable Specialist
RE: Farmers' Market in Crystal Springs this Summer

As part of the Crystal Springs Tomato Festival, to be held on Saturday, June 30, a Farmers' Market will be held downtown in Railroad Park. At this time, I would like to solicit growers who will have produce ready to sell by late June.

Any locally grown produce is acceptable. In late June, this might include tomatoes, bell peppers, hot peppers, summer squash, snap beans, southernpeas, butter beans, cabbage, sweet corn, cucumbers, okra, greens, watermelons, cantaloupes, herbs, shiitake mushrooms, etc.

Fruit crops can also be sold. These might include blueberries, peaches, blackberries, etc.

You don't have to be a full time grower to participate in this one-time Farmers' Market. If you have enough surplus from your garden and would like to sell it, you are welcome to join in.

All of the vendors who sold produce in last year's Farmers' Market did very well and most sold out.

There are, however, two requirements: 1) All produce for sale MUST be grown in Mississippi. Please do not bring fruits or vegetables from other states. 2) You must fill out and return the application to be allowed to sell your produce.

There is no fee for participants. Please fill out the application below and return it to:

Dr. Rick Snyder, Vegetable Specialist, Truck Crops Research & Extension Center, P.O. Box 231, Crystal Springs, MS 39059, or fax it to (601) 892-2056. Applications need to be turned in by June 15.

More information on the Tomato Festival can be found on the internet at http://www2.msstate.edu/~ricks/cstomato/tomfest.html .

Application to Participate in the
Crystal Springs Farmers' Market
June 30, 2001

 

Name:____________________________________________

Address:__________________________________________

Town, State, Zip:____________________________________

Phone:____________________________________________

List Vegetables You Intend to Sell:

 

 

 

List Fruits You Intend to Sell:

 

 

 

Other (cut flowers, honey, preserves, etc.):

 

 

 

Return this application to Dr. Rick Snyder, Vegetable Specialist, Truck Crops Research & Extension Center, P.O. Box 231, Crystal Springs, MS 39059, or fax it to 892-2056. Please return by June 15.

 

Calendar of Coming Events

June 19 - Second Annual ACEP Organic Agriculture Conference, Canton, MS. See article above for information.

June 23 - Sustainable Vegetable Field Day. See article above for information.

October 12 & 13 - Fall Flower & Garden Fest; Truck Crops Experiment Station, Crystal Springs, MS.

Dr. Richard G. Snyder
Vegetable Specialist
Truck Crops Research & Extension Center
Mississippi State University
P.O. Box 231
Crystal Springs, MS 39059
PHONE: (601) 892-3731
Fax: (601) 892-2056
Email: RickS@ext.msstate.edu

Web Pages:

Central Mississippi Research & Extension Center
http://www.msstate.edu/dept/cmrec/ 

North Mississippi Research & Extension Center
http://www.msstate.edu/dept/nmrec/

Greenhouse Tomato FAQ
http://www.msucares.com/crops/comhort/greenhouse.html

Vegetable Resource Page
http://www2.msstate.edu/~ricks/

Organic Fruit and Vegetable Web Page
http://www.msstate.edu/dept/cmrec/organic/ 

Greenhouse Tomato Short Course
http://www.msstate.edu/dept/cmrec/GHSC.htm

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