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
CitrusNominees Sought For Florida Agricultural Environmental Leadership Award
January 26, 2015
Honor recognizes those developing and adopting environmentally innovative farming practices. Read More
CitrusIncreased Global Trade Opportunity Equals New Threats For Crops [Opinion]
January 26, 2015
Despite expanding business abroad, Florida Agriculture Commissioner Adam Putnam says he's confident in the protocols in place to prevent entry of invasive pests and disease. Read More
CitrusShopping For UAVs? Here Are 2 To Consider
January 25, 2015
Check out a couple of high-flying options from Altavian. Read More
OrangesScientists Center On Sweet Spot For Processed Oranges
January 24, 2015
Unique approaches and techniques being employed to sustain and squeeze more out of critical research. Read More
BerriesIf You Could Plant Any Type Of Fruit, Consider A Caneberry [Opinion]
January 23, 2015
Raspberries or a blackberries present some berry good options. Read More
NutsNew Nut Industry Equipment
January 23, 2015
These new products are designed to make a nut grower's life easier. Read More
FruitsJiffy Pumped To Introduce New Produce Propagation System
January 23, 2015
PreGro concept to make its debut at Fruit Logistica. Read More
Apples & PearsSurvey: Positive Indicators For Biocontrols In U.S. Horticulture, Agriculture
January 22, 2015
Preliminary results of a survey conducted in December 2014 of more than 850 readers across six Meister Media Worldwide titles Read More
CitrusAsian Citrus Psyllid Marches North In California Citrus Belt
January 22, 2015
Part of one of the richest agricultural areas in the U.S., Fresno County, has been quarantined. Read More
Apples & PearsReal-World Solutions Highlight First Biocontrols 2015 Conference & Tradeshow
January 22, 2015
Topping the inaugural event's marquee are presentations on “Driving Crop Quality and Productivity Using Biocontrols” by representatives from two of the largest produce growing organizations in the country. Read More
The Latest
CitrusNominees Sought For Florida Agricultural Environmental …
January 26, 2015
Honor recognizes those developing and adopting environmentally innovative farming practices. Read More
CitrusIncreased Global Trade Opportunity Equals New Threats F…
January 26, 2015
Despite expanding business abroad, Florida Agriculture Commissioner Adam Putnam says he's confident in the protocols in place to prevent entry of invasive pests and disease. Read More
CitrusShopping For UAVs? Here Are 2 To Consider
January 25, 2015
Check out a couple of high-flying options from Altavian. Read More
OrangesScientists Center On Sweet Spot For Processed Oranges
January 24, 2015
Unique approaches and techniques being employed to sustain and squeeze more out of critical research. Read More
BerriesIf You Could Plant Any Type Of Fruit, Consider A Canebe…
January 23, 2015
Raspberries or a blackberries present some berry good options. Read More
NutsNew Nut Industry Equipment
January 23, 2015
These new products are designed to make a nut grower's life easier. Read More
FruitsJiffy Pumped To Introduce New Produce Propagation Syste…
January 23, 2015
PreGro concept to make its debut at Fruit Logistica. Read More
Apples & PearsSurvey: Positive Indicators For Biocontrols In U.S. Hor…
January 22, 2015
Preliminary results of a survey conducted in December 2014 of more than 850 readers across six Meister Media Worldwide titles Read More
CitrusAsian Citrus Psyllid Marches North In California Citrus…
January 22, 2015
Part of one of the richest agricultural areas in the U.S., Fresno County, has been quarantined. Read More
Apples & PearsReal-World Solutions Highlight First Biocontrols 2015 C…
January 22, 2015
Topping the inaugural event's marquee are presentations on “Driving Crop Quality and Productivity Using Biocontrols” by representatives from two of the largest produce growing organizations in the country. Read More
Food SafetyStill Plenty On The Plate Regarding Food Safety Moderni…
January 22, 2015
Almost two years after originally being proposed, four revised rules are still being picked over. Read More
MarketingFlorida Citrus Commission Probes Federal Marketing Orde…
January 21, 2015
Meeting to be scheduled for March to vet possibilities. Read More
Insect ControlExceptional Care Needed When Taking On Common Blossom T…
January 21, 2015
Learn how to identify, the survival and spread, as well as management methods for this insect pest of vegetables. Read More
VegetablesTakeaways From The 2015 Empire State Producers Expo
January 20, 2015
From crop protection pointers to potato breeding, there was no shortage of learning opportunities at the New York show. Read More
NutsNo More California Walnuts For China
January 20, 2015
Although China stopped buying California walnuts, exports to India are on the rise. Read More
NutsMeet The IPM Expert: Emily J. Symmes, UC Cooperative Ex…
January 20, 2015
Area IPM Advisor Emily Symmes helps growers preserve profits, quality and environmental stewardship through sound IPM practices. Read More
NutsSustainability Seminars Planned
January 20, 2015
Almond Board of California hosts modules on grower/huller management practices. Read More
CitrusBayer CropScience Launches Latest Insecticide, Sivanto
January 20, 2015
New product delivers precision pest control to preserve the health of plants and protect fruit and vegetable crops. Read More