Excellent economic thresholds have been established for the control of alfalfa weevil and alfalfa varieties that are susceptible to the potato leafhopper. If the economic threshold value is reached, take action by harvesting the crop, if time to do so, or apply a labeled insecticide that has a harvest restriction that is not going to delay harvest date. Watch vegetation for signs of leaf disease. If disease is limiting yield, quality and stand persistence, you will want to select resistant varieties in the future. Harvest quality hay.
Legumes are generally of higher quality than grasses and timeliness of harvest is essential.
You will want to complete harvest by the time legumes are in early flower and grass seed heads are fully extended, but before pollen shed. Harvesting hay in Indiana can be a challenge, but several technologies can reduce the risk of rain-damaged hay. While they can be useful in determining harvest date, don't get caught up in striving for a suggested quality level without regard to the incoming weather system's rain percentage. I'd rather harvest a day or two early in a good window of opportunity rather than risk waiting an extra day because the targeted quality level was not reached. Don't harvest alfalfa past early September.