Blue Diamond Almond Facts September-October 2022

Central Valley are connecting certain types of “new” pest pressures with the rise of the adoption of cover crop. As with any pest management system, there are many potential variables involved. A few factors must be briefly considered in this discussion while researchers investigate: First, things are rapidly evolving with the cessation of organophosphate insecticides. This means, in part, that when growers in the past would utilize this kind of chemical for pest control, other populations of pests were unintentionally kept at bay. At least, that is the initial thinking of the UC IPM system. 5 Now, with organophosphate materials out of play, populations of unseen pests inflicting such damage are rapidly rising. It is premature to suggest at this early stage that these pressures somehow need to be solely laid at the feet of cover crops implementation and adoption. Secondly, with roughly a decade of warm drought years, pest populations are increasing with temperatures. As it warms, pests are looking for three things — food/water, a mate, and a home. Certainly, a cover crop can harbor unwanted pests, just like your trees. However, initial data from growers suggests this is usually due to factors that

are out of the direct control of the almond operator. For example, when properties contiguous to almond orchards have certain annual row crops harboring pests, are cut in the annual rotation, the pests move to find food/water, a mate, or cover for a new home. The bottom line on this issue today is that we must work to adapt to new pest pressures. When implementing a cover crop program, we need the foresight to know that pest changes can become an issue — just as we must do when making other major changes to an orchard management system. A great example of a grower with drip who was able to watch the rain and catch it at the right time in October, producing cover crop bloom at almond bloom.

This grower needs a gold star. They timed the planting perfectly to coincide with fall rains. Brassica came up with almond bloom, then the grower did a high mow at leaf out to let the grass, peas, and bell come up. Taken last year in drought with a drip system!

5 As an example, see UC IPM’s work on the stink bugs in almonds:



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