Harvest Frequency Effects on Yield, Persistence, and Regrowth Rate Among New Alfalfa Cultivars

Alfalfa (Medicago sativa L.) is among the most important forage crops in the United States and consistently produces high yields and quality, with harvest frequency being one of the most significant factors affecting yield, quality, and persistence. The objective of this research was to determine forage yield, quality, persistence, and regrowth rate among new alfalfa cultivars under four different harvest frequencies for three growing seasons in Kentucky. Five cultivars were placed under harvest frequencies of 25, 30, 35, and 40 days in a split-plot design. The alfalfa cultivars were selected to represent a broad range of plant traits including rapid regrowth, lodging resistance, hybridization, fall dormancy, quality yield, and multi-pest resistance. Few differences were found between cultivars in yield, but the 25-day harvest frequency was among the lowest yielding, and also had the highest plant mortality. Harvest frequency also had a greater effect on regrowth rate than cultivar selection. These results confirmed that a 35-day harvest frequency is optimal for forage yield and stand persistence for most alfalfa cultivars tested in this study.