Does this scenario sound familiar? One young farmer related the story recently.
“My dad won’t let me start planting soybeans until other neighbors have planted beans. Our neighbors are mostly old-school and don’t plant soybeans until up in May. Dad says if we plant first like I want to, we will get all of the insects. Is that true? If so, what insects would we most likely get in the soybeans? Most importantly, does it make sense to delay planting soybeans just to avoid these insects?
The panel of Indiana Certified Crop Advisers answering this question this month are: Jesse Grogan, agronomist with LG Seeds, Lafayette; Greg Kneubuhler, owner of G&K Concepts, Harlan; and Tom Stein, manager of the Boswell and Templeton branches for Ceres Solutions.
Here are their thoughts on holding off planting soybeans because of the increased potential for more insects in the field. All three agronomists note that in general, planting soybeans early — from mid-April through early May — tends to provide the largest yield potential.
Grogan: You get the highest yields in soybeans usually by planting in the last week of April into early May. Insects that attack earliest-planted fields are those that overwinter as adults, such as the bean leaf beetle. These insects are effectively controlled by systemic insecticides in seed treatments such as Cruiser and Poncho.
Early-planted soybeans are most likely to benefit from a seed-applied insecticide, usually combined with a fungicide package. Rescue insecticide treatments are also an option when insects are identified and causing damage to emerging soybean plants. Do not delay planting to avoid insects. Yield potential from timely planting is more important.
Kneubuhler: The risk of increased insect issues would be a very minor concern of mine relative to planting date. In our opinion, the opportunity of yield improvement by planting early far outweighs the risk of insects.
Typically, the early-planted beans may see higher bean leaf beetle feeding. However, we can handle a fair amount of defoliation that early in the season before warranting any kind of treatment. It’s always good management to have a solid scouting program, but I would never let the threat of insects delay my soybean plantings.
Stein: Yes, that is true that if you have the earliest-planted soybeans in the area, your fields may attract insects early in the season. The first-planted soybeans in the area will be more susceptible to insects that have overwintered such as bean leaf beetles.
I would not delay planting to avoid these insects. What I would do is use an Integrated Pest Management approach as the most economically sound way to protect yield potential while limiting environmental hazards and input costs. An IPM approach utilizes field scouting, pest monitoring, host resistance, biological control and chemical control when thresholds of a pest are reached.