The warm, wet conditions found in Region 10 give way to an unfortunately ideal environment for certain pest and disease pressures, including wireworm, seedcorn maggot, rhizoctonia and phytophthora. Keep good record of where these pests are found so that you can prevent yield loss to them in subsequent years. Selecting a variety with good disease tolerance is the best control for phytophthora and rhizoctonia, while a seed-applied insecticide is an ideal way to prevent damage from wireworm and seed corn maggot.
Another area of concern is herbicide carryover, particularly in soybeans. Last year's dry summer and fall has caused a delay in the breakdown of many of the herbicides we use. The wet spring has resulted in stunted, less vigorous plants with a reduced ability to metabolize carryover herbicides. When coupled with the fact that many soybean plants are switching to their nodal root system for their primary source of nutrients, I'm beginning to see quite a few fields with herbicide carryover concerns. Whether it's the heart-shaped soybean leaf caused by acetachlor or the bleached look of a photosynthesis inhibitor, these symptoms are beginning to show up in quite a few soybean fields, especially in the overlaps. I don't expect to see much yield loss due to these carryover situations, but it does add another stressor to the plant at a critical time.
White mold also thrives in seasons of high moisture levels, coupled with high temperatures. Keep an eye out for it later in the season, particularly in soybeans. You can recognize white mold by dead leaves on top of bushy plants, and as it progresses, a white mold appears on the stems. The good news is, many still have time to lessen the damage from this pressure with fungicide. The best time to spray is during R2-R3 stage, when pods first develop.
To learn more about how you can treat and prevent pest and disease pressures in your field, contact me or a Regional Sales Agronomist in your area.