David Owens, Extension Entomologist, owensd@udel.edu
Soybean
Its about time soybeans might receive a herbicide application. It is tempting to tank mix an insecticide with it, but after testing herbicide pyrethroid tank mixes on 9 field site years with large field-size, sprayer-wide strip trials, we have never seen a significant yield response. Remember, vegetative soybeans can take a real beating without losing yield potential (many studies have shown that the true yield limiting defoliation before R1 is greater than 50%.
Alfalfa
Scout alfalfa for potato leafhopper. Varieties with glandular trichomes are much more resistant to PLH than those that are not. Guidance and threshold tables can be found here: https://www.udel.edu/content/dam/udelImages/canr/pdfs/extension/sustainable-agriculture/pest-management/Insect_Control_in_Alfalfa_-2023.pdf. There are quite a few materials labeled for leafhopper. Alfalfa at bud stage can be harvested a bit early. Alfalfa in bloom should be scouted for blister beetles.