There are many soybean fields this year that have great yield potential. Looking at fields for disease and insect pressure has proven that insect feeding is there and they can greatly damage your yields. According to Jared O’ Connell, Global Marketing Manager for BASF, the global crop loss caused by insects equals $470 billion each year. A figure toping a 39% loss from diseases and insects, compared to a 13% loss attributed to weeds.
In recent field scouting, we have seen an invasion of Japanese Beetle on not only soybeans, but corn too. These larva feed off the roots of grass plants and cover crops, so if you have cover crops, make sure to watch for beetle pressure. Treatment should be considered at 20% leaf defoliation for reproductive growth stage soybeans. Later planted fields are at a greater risk. Use products with a quick knockdown and pay attention to residual. Japanese beetles are mobile and residual control will not last as long. They also tend to feed on the bottom of the plant so using an adjuvant can help spray go deeper into the canopy.
Been Leaf Beetle was also just found in early planted bean fields in Logan County, Ohio. There was significant defoliation which will affect bean quality and yield. An important thing to remember about adult been leaf beetles is that they can transmit the bean pod mottle virus which can cause green stem and delay harvest.
Another insect to watch for this year is the Grasshopper. Several species will feed on soybean foliage and typically move into fields during July and August. They may also feed on and damage soybean pods. Treatment may be necessary if you have 40% or more defoliation before soybean flowering. Most of us are at the flowering to pod stage now which can be greatly affected if there is 15% defoliation and 25% from pod to grain fill.
It is important to scout your fields right now because this is the typical time insects can rob you of your yield potential. It doesn’t take much damage from pests to reach an economic threshold justifiable for an insecticide application. Insecticides can easily be added to your fungicide applications. For any help on field scouting or insecticide recommendations, please don’t hesitate to call us and we can direct you to a local Associate Partner.