Grazing‐Tolerant Alfalfa Cultivars Perform Well under Rotational Stocking and Hay Management

Abstract

Grazing‐tolerant alfalfa (Medicago sativa L.) cultivars are developed using continuous stocking with beef cattle (Bos taurus) during screening and selection. Alfalfa is mainly recommended for use in hay making and under rotational stocking rather than continuous stocking. Performance of alfalfa cultivars selected under the specificity of intensive, continuous stocking in recommended management systems is unknown. This study was conducted to test survival and performance of alfalfa populations selected with continuous stocking against their parental cultivar germplasms (‘Apollo’, ‘Diamond’, ‘5432’, and ‘Florida 77’) at two Georgia locations (Eatonton and Tifton) under the following management conditions: grazing to close stubble heights (5–7 cm) with continuous stocking, grazing to close stubble heights (5–7 cm) with rotational stocking (7 d grazing and 28 d rest), and standard hay harvesting. At Eatonton, plant survival was similar (52–53%) for the rotational stocking and hay harvest treatments, with all entries in these treatments exhibiting better survival than in the continuously stocked treatment (38%). At Tifton, stand survival improved as management changed from continuous stocking (24%) to rotational stocking (46%) to hay harvest management (63%). At both test locations, grazing‐tolerant entries demonstrated higher plant survival rates than parental populations when averaged across all management treatments. Dry matter yields of the grazing‐tolerant entries were no different, or were higher during 1 yr at Tifton, than their parental populations. It is therefore a good strategy for producers practicing continuous stocking, rotational stocking, or hay making to use grazing‐tolerant cultivars rather than cultivars not selected for grazing tolerance.