Managing forages

By Jason Hartschuh, Ohio CCA Board Chairman, OSU Extension Field Specialist, Dairy Management and Precision Livestock

When should you scout for insect management in forages?

Weather patterns have direct impacts on forage insect pressure. The first challenge to emerge is alfalfa weevil larvae, with peak feeding occurring when growing degree days are between 325 and 575. The larvae make a small hole in the alfalfa leaf. When plants are less than 12 inches tall, one larva per stem is the economic threshold for an insecticide application. After an insecticide application, be sure to scout for insecticide resistance. Pyrethroid resistance in alfalfa weevil has been found in numerous western states, with other states reporting decreased efficacy.

The next major insect challenge to alfalfa is the potato leafhopper (PLH). These insects blow in on southern winds, usually late into the first cutting or during second cutting regrowth. Potato leafhoppers rapidly reproduce, completing a generation in about three weeks, with multiple generations present simultaneously.… Continue reading