Even though it may not feel like it, spring has arrived.  Now that a number of vegetable crops are in the ground, we’ve pretty much lost the option to apply preemergent herbicides.  Because of this, we need to focus on selective and directed postemergent herbicide options.  There are a few postemergent herbicide options for vegetable crops.  And even fewer available if you’re looking to control broadleaf weeds, since most vegetable crops are broadleaves.

Grassy Weed Control

Sethoxydim

Sethoxydim goes by a number of trade names with the most commonly available being Poast®.  It provides selective control of grassy weeds such as bermudagrass, crabgrass, and goosegrass.  Sethoxydim is to be sprayed over-the-top of most vegetable crops and a surfactant is required to be tank mixed with this product.

Clethodim

Like sethoxydim, clethodim provides selective control of grassy weeds including bermudagrass and crabgrass, but it does not always control goosegrass.  The most commonly available clethodim containing product is SelectMax®, but like sethoxydim it is off-patent and available under a lot of trade names.  It is to be sprayed over-the-top of most vegetable crops and a surfactant is required to be tank mixed with this product.

Broadleaf and Sedge Weed Control

Halosulfuron

The most commonly available trade name for halosulfuron is Sandea®, but a number of generic products are available.  It controls a variety of weeds including pigweed, wild radish, yellow nutsedge, and purple nutsedge.  Halosulfuron is to be sprayed over-the-top of most vegetable crops and a surfactant is required to be tank mixed with this product.

Bentazon

Bentazon is available in generic formulations, but it is most commonly available under the trade name Basagran®.  It controls broadleaf weeds and yellow nutsedge in legume crops and sweet corn.  Bentazon is to be sprayed over-the-top of most vegetable crops and a surfactant is required to be tank mixed with this product.

Non-selective Herbicides

Non-selective herbicides kill or injure most plants they come into contact with.  Glufosinate, carfentrazone, and paraquat are labeled for weed control in most vegetable crops.  These products are to be used as directed sprays and spray shields and low pressure are recommended to reduce drift.

Surfactants are required to be tank mixed with most of these herbicides.  Surfactants can increase volatility and vaporability, so avoid spraying in the middle of the day during hot days.  Please check the product label for surfactant recommendations and rates.  Always read and follow the label.  Label information can be found on the EPA’s website.  The products listed in this article are commonly used herbicides in vegetable crops.  For a more comprehensive list of products labeled for specific crops please refer to the Vegetable Production Handbook of Florida.  Most, if not all, product labels recommend spraying weeds when they are young and before they flower.  Labels also recommend not spraying when weeds are under drought stress.  When plants are stressed, they limit gas exchange by closing their stomata, which are tiny pores in stems and leaves.  This action reduces a plant’s ability to take up herbicides.

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