Integrated Crop Management News

Earlier this spring, we discussed using the PEAQ method (Predictive Equations for Alfalfa Quality) to help determine when to harvest first crop alfalfa. Looking at the PEAQ measurements made around the state, we are getting close to taking the first crop alfalfa.

This growing season, delayed planting, combined with continued cool and wet conditions have taken their toll on crops that were planted in the brief periods of optimum weather. Given that there is already delayed emergence, and the wet and cool weather patterns are expected to continue, we could very well see continued delayed growth and development of crops. This means that we can also expect reaching grain fill later in the growing season, which creates a window of opportunity for plant diseases to impact total yield.

Nitrogen (N) fertilization for this year’s Iowa corn crop has been complicated by frequent and sometimes excessive rainfall from late last fall through this spring. Many farmers who normally apply N in the fall couldn’t, and spring preplant N application and corn planting has been challenging in many areas with the wet and extended cold soil conditions. Therefore, many farmers are uncertain about the N availability for corn, early post-emergence assessment of soil N supply, and the potential for supplemental sidedress N application.

Keep alfalfa weevils in mind while scouting for stands and evaluating for winter injury. A recent ICM News article gave some great tips for assessing winter injury and providing additional resources. Adult alfalfa weevils become active and start laying eggs as soon as temperatures exceed 48°F. Alfalfa weevil eggs develop based on temperature, or accumulating degree days, and hatching can start around 200-300 degree days.