MID-SEASON SOYBEAN DISEASES ARE MAKING AN ENTRANCE INTO FIELDS
Jul 31, 2020
Are you seeing an occasional wilted plant out in a soybean field? Over the last few weeks, mid-season soybean diseases, including Phytophthora began making their entrance into fields within Agtegra territory. A unique characteristic of Phytophthora is that the disease can potentially kill plants from the time of planting nearly until harvest – mostly, coming in one of the two following stages:
Unfortunately, foliar fungicides are not effective for this mid-season disease. To best manage mid-season Phytophthora, select soybean varieties with robust genetic packages for resistance genes, high field tolerance ratings and to the extent possible, improve aeration and drainage in soils.
- SEEDLING STAGE: Water molds like Pythium and Phytophthora are most prevalent when soybean seeds are planted in an overly wet soil. These diseases send out mobile spores to infect seedlings causing significant stand losses. The difference between these Pythium and Phytophthora is their preferred temperature. Pythium succeeds in cold and wet conditions, where Phytophthora prefers a slightly warmer soil. Water molds like these can be combatted with seed treatments like CruiserMaxx Vibrance® and by working with your Agtegra Agronomist to select a soybean variety with effective, and possibly multiple Phytophthora resistant genes.
- MID-SEASON: Phytophthora is likely to remain in the warmer soil and possibly infect plants as seed treatments begin to wear off. Entering through the roots, Phytophthora can work its way up the stem giving the plant a wilted look. In addition to wilting, a chocolate brown coloration of the lower stem with infection ending in a very clear line between brown and green are key identifying characteristics.
Unfortunately, foliar fungicides are not effective for this mid-season disease. To best manage mid-season Phytophthora, select soybean varieties with robust genetic packages for resistance genes, high field tolerance ratings and to the extent possible, improve aeration and drainage in soils.