VARIETY, FERTILIZER, MANAGEMENT INTERACTIONS IN ALFALFA

Abstract

An experiment was conducted for the purpose of studying over a 4-year period the interactions to be found among four alfalfa varieties differing in winter hardiness and wilt reaction, six fertilizer treatments differing quantitatively and qualitatively, and three management systems differing in the frequency and timeliness of cutting.In the second crop year hardiness was the main factor in determining both yields and stands; bacterial wilt was of somewhat less importance. In the third crop year wilt became the main factor. Varieties differed significantly in their reaction to potash, to phosphorus and to the severity of cutting treatments. Phosphorus helped the winter-hardy varieties more than the non-hardy, whereas potash was of greater benefit to the winter-susceptible varieties.The management system which included a September clipping was detrimental to all varieties and particularly to the less hardy ones, DuPuits and Ranger. Only with the hardy varieties, Vernal and Grimm, was it feasible to attempt to compensate by the addition of fertilizers for the mismanagement involved in untimely cutting.