Growing Season Pains

Now that planting and replant is finally coming to an end, we’re focusing on nutrient deficiencies, weed control and pests. Here’s what we are keeping an eye on.

Nitrogen management
Excessive rainfall in early planting season has caused growers to question how much nitrogen (N) was lost. Soil sampling and measuring the concentration of nitrate- and ammonium-N remaining in the root zone can indicate if the plant or soils are N deficient. Providing N on a timely basis (V4-V6 stage) is critical for maximizing yield potential. Last week’s edition of the Purdue Pest and Crop Newsletter has an extensive article on sampling and assessing current soil N availability. Call us to discuss your specific situation as the N cycle is highly complicated. Also, look out for sulfur deficiency, which can cause striping or yellowing of corn leaves.

Weed control
Be aggressive on weeds and scout fields thoroughly for outbreaks. Avoid applications during windy, hot conditions. When assessing plant maturity for herbicide safety, use leaf collar as well as plant height, as much of the corn is shorter than normal due to the early season stresses. Always read and follow label directions. 

Insect pests
Corn rootworm hatch is underway and will continue for several weeks. In about two weeks, you will be able to dig up and inspect for larvae and feeding scars on the roots. Scout non-Bt corn for European corn borer (ECB) first-brood injury when corn is in the whorl stage and foliar injury is present. Treat if at or above the well-developed thresholds for this insect, taking into account feeding damage, number of live larvae, and expected corn price. We continue to find Asiatic garden beetle grub in northeastern Indiana on light-textured soils. Watch for increasing levels of potato leafhoppers on alfalfa and apply insecticide based on the recommended threshold for your area.

Double cropping
Wheat harvest is underway in Kentucky and southern Indiana and southern Ohio.  Many growers will soon be planting double crop soybeans. The rule of thumb for double crop soybeans is to increase the seeding rate by 5 percent each week after May 20. Planting narrower rows decreases the days to canopy closure and increases the yield potential. We recommend a population of at least 220,000 plants/acre and 7.5 inch or 15 inch rows as a general guideline for double crop soybeans.

As you’re making management decisions, please give us a call with any questions

Terry, Dan, Rod and Dennis