A comparison of New Zealand and overseas white clover cultivars under grazing in New Zealand

A large number of white clover cultivars bred both in New Zealand and overseas are available for use by New Zealand pastoral farmers. Unfortunately, there is little published data on the merits of these cultivars under New Zealand conditions. Data from a series of trials established in the Manawatu between 1996 and 2005, containing a range of cultivars from Europe, the Mediterranean, North and South America and New Zealand were used in a meta-analysis to assess the general adaptive yield and persistence potential of these contrasting cultivar types. All trials were maintained over two to four years, and revealed significant cultivar effects. Overall, New Zealand bred cultivars showed better adaptation than overseas cultivars in these New Zealand-based trials. However, overseas cultivars containing Mediterranean germplasm, particularly from southern France, Italy and Syria exhibited beneficial features in the trials, and many recently bred New Zealand cultivars contain germplasm from these origins. In addition to using the appropriate parent germplasm when developing cultivars, it is equally important to evaluate and select under local conditions in competition with grass under grazing over multiple years. New Zealand farmers may benefit from an industry-wide benchmarking system for white clover cultivars, possibly by incorporation into the Forage Value Index.