Rotations for pest resistance management

Dec.8, 2011 - Issue 28

A quick explanation of why rotation matters for pest management: Lack of crop diversity can increase the density of pests in a field. The higher the population of a pest in a field, the higher the risk of developing resistance to the pesticides (herbicide, fungicides or insecticides) used for controlling the pest in those fields. Why? The genetic coding for resistance to pesticides is found in very low numbers within a pest population, but the higher the density of the pest, the more likely a resistant individual will be present. The goal of resistance management, regardless of the class of pest, is to maintain that frequency of resistant individuals at a very low level within the total population. Once the frequency of that resistant type makes up the majority of the total population the chemistry that it is resistant to will no longer provide effective control. By the time resistance in the pest population becomes obvious, it may be too late to manage effectively.

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