CULTIVAR-ENVIRONMENT INTERACTIONS IN RED CLOVER
The performance of nine double-cut and three single-cut red clover (Trifolium pratense L.) cultivars was studied at five locations in Atlantic Canada. The single-cut clovers survived relatively well at all locations while the double-cut clovers did not survive well at one location during the first winter. An analysis of data for total dry-matter yield from five environments, i.e., location-year combinations, showed that the single-cut clovers outyielded the double-cut clovers in Newfoundland but yielded lower at the other locations. Among the double-cut cultivars, Florex, Lakeland, Tapiopoly, and Violetta were found to be desirable cultivars because they had a high mean yield and did not yield lower than the population average at any of the five environments. A large cultivar-environment interaction variance was detected for the double-cut cultivars; therefore, at least 15 test environments are required in future trials in order to detect a yield difference of 6% by multiple comparison procedures.Key words: Trifolium pratense L., stability