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Vegetable IPM Updates Archive
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Timing the Chemigation of Vegetable Herbicides (November 25, 2015)
Some of the herbicides used on vegetables can be applied through the sprinkler system. Sprinklers are designed to apply water , not herbicides, and care must be used to avoid poor weed control or crop injury. Timing of the application is especially important and varies with each herbicide. Prefar, for instance, sticks strongly to the soil and it takes a lot of water to move it into the soil where the roots can contact it. Kerb, on the other hand, does not adhere very well to the soil and it is easily leached below the germinating weed seeds if put on too early. Prefar does not have any postemergence activity and must be applied before the weeds germinate. Kerb has early postemergence activity on small weeds and can still kill them after germination. Dacthal can be chemigated on direct seeded and transplanted cole crops. It adheres strongly to fine textured soils and does not work well if the soil is too dry when chemigated. If soil moisture is present at application there will be less soil surface to tie up the herbicide and control will be better. The dinitroaniline (yellow) herbicides adhere strongly to fine textured soil and should be mechanically incorporated on direct seeded vegetables or severe crop injury can occur. These include Balan, Prowl and Treflan and , in general, they should not be applied through sprinkler systems.

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