2018 Crop Protection Guide for Tree Fruits in Washington

Pesticide Resistance Management

Thursday, August 16, 2018

Herbicide Resistance Management

Herbicide resistance management follows the same principles as for insecticides and fungicides.  The best practice is to not spray, and use non-chemical methods for reducing the soil seed bank.  Non-chemical methods include soil cultivation to control emerged plants and bury non-germinated seed, irrigation and water management, mowing, and burning.  When chemical control is necessary, rotations and mixtures should be employed.

Rotation of herbicides among unique modes of action also reduces the risk of resistance evolution, avoiding repeated applications of materials within the same class.  In addition to rotations, mixing herbicides with different modes of action can slow resistance evolution.  It is important, however, when mixing herbicides that they have different modes of action, and that each of the materials be effective against the target weed species. 

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