Tips For Tomato Weed Control

Weed control in tomatoes is always important, but when you consider some common weeds are hosts of pests and disease, it is even more critical. Weeds such as nightshade and voluntary tomatoes are hosts to threats like sweet potato whitefly, bacterial spot, and other viruses.

According to a report by William M. Stall, UF/IFAS horticulturist, control of these weeds is necessary to help control such pests. He suggests thinking of weed control in terms of the entire farm, not just actual crop areas such as row middles. Weed hosts can flourish in ditches, fence rows, and fallow fields. These weeds can serve as a reservoir for reinfestations of crops. 

Disking is probably the least expensive weed control procedure for fallow fields. Where weed growth is mostly grasses, clean cultivation is not as important as in fields infested with nightshade and other disease and insect hosts. In the latter situation, weed growth should be kept to a minimum throughout the year. If cover crops are planted, they should be plants that do not serve as hosts for tomato diseases and insects. Some perimeter areas are easily disked, but berms and field ditches are not, so some form of chemical weed control may have to be used in these areas.

“We are not advocating bare ground on the farm as this can lead to other serious problems, such as soil erosion and sand blasting of plants,” states Stall. “However, where undesirable plants exist, some control should be practiced, if practical, and replacement of undesirable species with less troublesome ones, such as bahiagrass, might be worthwhile.

“Certainly fence rows and areas around buildings and pumps should be kept weed free, if for no other reason than safety. Herbicides can be applied in these situations, provided care is exercised to keep them from drifting onto the tomato crop. Field ditches and canals present special considerations because many herbicides are not labeled for use on aquatic sites. Where herbicidal spray may contact water and be in close proximity to tomato plants, for all practical purposes, growers probably would be wise to use diquat only.”

Nightshade Nightmare

In his report, Stall notes that nightshade has become one of the most problematic weeds facing Florida tomato growers. It has developed varying levels of resistance to some post-emergent herbicides in different areas of the state.

Best control with post-emergence (directed) contact herbicides is obtained when the nightshade is 4 to 6 inches tall, rapidly growing, and not stressed. Two applications of approximately 50 gallons per acre using a good surfactant are usually necessary.

With post-directed contact herbicides, several studies have shown that more than 60 gallons per acre will actually dilute the herbicides and therefore reduce efficacy. Good leaf coverage can be obtained with volumes of 50 gallons or less per acre. A good surfactant can do more to improve the wetting capability of a spray than can increasing the water volume.

Postharvest Pointers

It is all about good field sanitation in tomato production, which starts with fast and complete dessication of tomato vines after harvest. In season, the large canopy of tomato plants makes it more difficult for pesticide penetration, thus lending itself to whitefly survival.

Sweet potato whitefly populations will continue to grow until tomato vines are killed. It is advised that growers continue spraying for whiteflies until the crop is destroyed. Gramoxone Inteon (paraquat, Syngenta Crop Protection) and Firestorm (paraquat dichloride, Chemtura Corp.) are labeled for postharvest desiccation of tomato vines. Follow the label directions.

Stall concludes that turning off irrigation and letting vines die is a poor choice over rapid dessication.

Leave a Reply

4 comments on “Tips For Tomato Weed Control

  1. As a market farmer, I would like to see
    more articles of interest to small farmers
    growing for farmers markets.
    Also, we would probably use more pesticides if they were available in small
    farm quantities instead of 2 1/2 gal. jugs.

  2. As a market farmer, I would like to see
    more articles of interest to small farmers
    growing for farmers markets.
    Also, we would probably use more pesticides if they were available in small
    farm quantities instead of 2 1/2 gal. jugs.

Featured Stories
Operation Outdoor Freedom participants
CitrusFlorida Proud To Be Home Of The Brave [Opinion]
May 25, 2015
Operation Outdoor Freedom invites wounded service members and veterans of the U.S. military to enjoy recreational activities in state forests and on private lands. Read More
OrganicDavid Peri of Peri & Sons Receives Outstanding Agriculturalist Award
May 22, 2015
David Peri, president of Peri & Sons Farms, has been named the 2015 Nevada Outstanding Agriculturalist Award by the University Read More
FruitsQ&A With Penn State’s New Young Grower Alliance Coordinator
May 22, 2015
Erin Dugan recently joined Penn State University extension as a specialty crop innovations program manager and Young Grower Alliance coordinator. Read More
FruitsHow To Start A Young Grower Association
May 22, 2015
You have recently returned to your family’s business. You have friends and family you can tap for their knowledge and Read More
Tomato bug
Insect ControlStop Tomato Bugs From Sucking Your Crops Dry
May 21, 2015
Learn how to identify, the survival and spread, as well as management methods of this vegetable pest. Read More
UF/IFAS developmental biologist Dennis Gray looks at the progress of grapevines in a vineyard.
Crop ProtectionResearcher Using ‘Precision Breeding’ To Create Disease-Resistant Winegrapes
May 20, 2015
Breakthrough would mean significant savings on pesticide and fungicide sprays. Read More
Spraying indoor citrus
Protected AgricultureInterest Continues To Grow In Protected Citriculture
May 20, 2015
Inside move could put producers in prime scoring position. Read More
Expansion groundbreaking for Southwest Florida Research and Education Center
CitrusSouthwest Florida Research And Education Center Embracing New Expansion
May 20, 2015
A 7,000-square-foot addition to the UF/IFAS facility will house labs and offices for potential new faculty members. Read More
storm clouds
CitrusSouth Florida Rainy Season Could Wind Up On Drier Side
May 20, 2015
National Weather Service anticipating El Niño to play a hand in possible below-normal conditions. Read More
Food SafetyProduce Safety Alliance Offers Course To Become A Certified Trainer
May 20, 2015
The Produce Safety Alliance (PSA) has announced dates for their first two Train-the-Trainer courses this June. The first of the Read More
The Latest
Operation Outdoor Freedom participants
CitrusFlorida Proud To Be Home Of The Brave [Opinion]
May 25, 2015
Operation Outdoor Freedom invites wounded service members and veterans of the U.S. military to enjoy recreational activities in state forests and on private lands. Read More
OrganicDavid Peri of Peri & Sons Receives Outstanding Agri…
May 22, 2015
David Peri, president of Peri & Sons Farms, has been named the 2015 Nevada Outstanding Agriculturalist Award by the University Read More
FruitsQ&A With Penn State’s New Young Grower Alliance Coo…
May 22, 2015
Erin Dugan recently joined Penn State University extension as a specialty crop innovations program manager and Young Grower Alliance coordinator. Read More
FruitsHow To Start A Young Grower Association
May 22, 2015
You have recently returned to your family’s business. You have friends and family you can tap for their knowledge and Read More
Tomato bug
Insect ControlStop Tomato Bugs From Sucking Your Crops Dry
May 21, 2015
Learn how to identify, the survival and spread, as well as management methods of this vegetable pest. Read More
UF/IFAS developmental biologist Dennis Gray looks at the progress of grapevines in a vineyard.
Crop ProtectionResearcher Using ‘Precision Breeding’ To Cr…
May 20, 2015
Breakthrough would mean significant savings on pesticide and fungicide sprays. Read More
Spraying indoor citrus
Protected AgricultureInterest Continues To Grow In Protected Citriculture
May 20, 2015
Inside move could put producers in prime scoring position. Read More
Expansion groundbreaking for Southwest Florida Research and Education Center
CitrusSouthwest Florida Research And Education Center Embraci…
May 20, 2015
A 7,000-square-foot addition to the UF/IFAS facility will house labs and offices for potential new faculty members. Read More
storm clouds
CitrusSouth Florida Rainy Season Could Wind Up On Drier Side
May 20, 2015
National Weather Service anticipating El Niño to play a hand in possible below-normal conditions. Read More
Food SafetyProduce Safety Alliance Offers Course To Become A Certi…
May 20, 2015
The Produce Safety Alliance (PSA) has announced dates for their first two Train-the-Trainer courses this June. The first of the Read More
GrapesMatthew Fidelibus To Be Recognized For Extension Work
May 20, 2015
The American Society of Enology and Viticulture (ASEV) recently announced that Western Fruit Grower™ magazine contributor Matthew W. Fidelibus, of Read More
Apples & PearsGrants Available For Farmworker Education
May 19, 2015
Grants are available for farmworkers and their families interested in attending adult educational programs through the Washington Apple Educational Foundation Read More
Fruits$10 Million Available For California Water Conservation…
May 19, 2015
Applications for the California Department of Food and Agriculture’s (CDFA) California State Water Efficiency and Enhancement Program (SWEEP) are now Read More
CitrusBad Weather Or Not, Preparation Always On Radar For Flo…
May 19, 2015
You cannot prevent a natural disaster from taking everything you have, but you can lessen the blow if and when it happens. Read More
Sweet CornGrower, Marketer Team Up To Launch Line Of Single-Serve…
May 19, 2015
Next Level Fresh, LLC announced the introduction of Fresh Life Harvest Whole Ear Gourmet Sweet Corn. The concept was developed Read More
CitrusSave Your Greenhouse Structures From Storms
May 19, 2015
Make sure your protected agriculture components are prepared for whatever may blow this way. Read More
FruitsGreen Fruitworm Numbers High In Pennsylvania
May 19, 2015
In their latest insect report, David Biddinger and Grzegorz Krawczyk, tree fruit entomologists discuss the timing of pest control applications Read More
Apples & PearsApple Scab Alert
May 18, 2015
Kari Peter of Penn State University Extension warned growers of possible apple scab and fire blight infections following the rainy Read More