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
A soil map is an excellent starting point when planning an orchard. (Photo credit: David Eddy)
Citrus
August 31, 2016
Ag Robots And Drones May Be A $10 Billion Market By 2022
A new report analyzes how the robotic market and technology developments will change the business of agriculture. Read More
caution tape close-up with impatient individual standing behind it
Citrus
August 30, 2016
USDA Offices Closed After Unspecified Threat
Agency locations in five states shuttered due to anonymous, but serious messages. Read More
Cosmis Crisp apples planting FEATURE
Fruits
August 30, 2016
Fresh Fruit Isn’t Always Fresh Picked [Opinion]
It’s important we educate consumers on what fresh fruit means. Read More
Photo credit: USDA
Fruits
August 30, 2016
Farmworker Overtime Expansion Sent To California Governor’s Desk
Allied industries say new regulation is burdensome when coupled with increase in minimum wage. Read More
Tamarixia radiata is a predatory wasp that attacks the nymphs of Asian citrus psyllid. (Photo credit: CDFA)
Insect & Disease Update
August 30, 2016
Parasitic Wasps Released In Fight Against Asian Citrus Psyllid
Release in residential areas a proactive move against threat of citrus greening. Read More
sweet corn field shot Gordon
Sweet Corn
August 30, 2016
Abbott & Cobb Forms Licensing Agreement With Syngenta
The long-term agreement involves licensing Abbott & Cobb’s patented SuperSeedWare technology to Syngenta Seeds for use in sweet corn varieties.  Read More
Cut sugarcane in South Florida
Citrus
August 30, 2016
Scientists Fervent To Find Cure For Deadly Sugarcane Virus
Now spreading to sorghum, yellow leaf malady could infect millions of crops from Florida to Texas. Read More
2-spotted spider mites
Crop Protection
August 30, 2016
New Biopesticide Available From BioWorks
Mycoinsecticide has quick knockdown effect and multiple modes of action. Read More
(Photo credit: Wikimedia Commons)
Citrus
August 30, 2016
Monsanto And Bayer Merger Talks Advancing
Sources says companies have addressed initial issues from initial conversation. Read More
honeybee
Fruits
August 30, 2016
Minnesota Governor Restricts Neonicotinoid Use
Executive order issued to reverse, minimize negative impact on bees and other insect pollinators. Read More
The Latest
Citrus
August 31, 2016
Ag Robots And Drones May Be A $10 Billio…
A new report analyzes how the robotic market and technology developments will change the business of agriculture. Read More
Citrus
August 30, 2016
USDA Offices Closed After Unspecified Th…
Agency locations in five states shuttered due to anonymous, but serious messages. Read More
Fruits
August 30, 2016
Fresh Fruit Isn’t Always Fresh Picked [O…
It’s important we educate consumers on what fresh fruit means. Read More
Fruits
August 30, 2016
Farmworker Overtime Expansion Sent To Ca…
Allied industries say new regulation is burdensome when coupled with increase in minimum wage. Read More
Insect & Disease Update
August 30, 2016
Parasitic Wasps Released In Fight Agains…
Release in residential areas a proactive move against threat of citrus greening. Read More
Sweet Corn
August 30, 2016
Abbott & Cobb Forms Licensing Agreem…
The long-term agreement involves licensing Abbott & Cobb’s patented SuperSeedWare technology to Syngenta Seeds for use in sweet corn varieties.  Read More
Citrus
August 30, 2016
Scientists Fervent To Find Cure For Dead…
Now spreading to sorghum, yellow leaf malady could infect millions of crops from Florida to Texas. Read More
Crop Protection
August 30, 2016
New Biopesticide Available From BioWorks
Mycoinsecticide has quick knockdown effect and multiple modes of action. Read More
Citrus
August 30, 2016
Monsanto And Bayer Merger Talks Advancin…
Sources says companies have addressed initial issues from initial conversation. Read More
Fruits
August 30, 2016
Minnesota Governor Restricts Neonicotino…
Executive order issued to reverse, minimize negative impact on bees and other insect pollinators. Read More
Fruits
August 30, 2016
Western Growers Opens AgTech Innovation …
Startup companies can apply to compete for ag industry resources. Read More
Berries
August 29, 2016
New Source For High And Low Tunnel Berry…
TunnelBerries project offers resources for growers, Extension agents, and those interested in berry production under cover. Read More
Apples & Pears
August 29, 2016
Public Comments Now Accepted For ‘Arctic…
APHIS releases determination to extend deregulation to third release from Okanagan Specialty Fruits. Read More
Potatoes
August 29, 2016
U.S. Potato Exports Reach Second Highest…
Prospects for continued growth in exports look good but the strong dollar and increased competition will continue to moderate this growth. Read More
Food Safety
August 29, 2016
10 Takeaways From The Center For Produce…
A couple of the key points from the symposium include knowing the importance of sampling irrigation water sources correctly and knowing the difference between validation and verification. Read More
Apple Grower of the Year
August 27, 2016
Rock Steady U.S. Apple Crop Forecast
USApple predicts 2016 output will be just slightly higher than in 2015. Read More
Grapes
August 27, 2016
Managing Water In California Vineyards
National viticulture symposium provides insights into estimating vineyard irrigation requirements. Read More
Grapes
August 26, 2016
Model Vineyard Looks To Maximize Concord…
Watching Michigan ‘‘Concord’’ grape growers struggle with stagnant and sometimes declining prices, a team of researchers at Michigan State University Read More
[gravityform id="62" title="false" description="false"]