Effect of Boron and Nitrogen Application on Seed Production of Lotus uliginsus

Four rates or boron (B) and 2 rates of nitrogen (N) were applied to a mature stand of lotus 11ligi11os11s Schk. cv. Grasslands Maku before flowering, on 10 November 1988. The 2 rntes of N (40 and 80 kg N/ ha) were either applied once or applied at 5 and 10 kg N/ha respectively, at weekly intervals for 8 weeks. N did not increase seed yields. Weekly applications of N significantly (P<0.05) decreased seed yields by 28%. B at 0.91 kg/ha increased seed yields by 7% but this increase was not significant. While seed yields in some tropical legumes may benefit from N application, Grasslands Maku does not benefit. Rather, seed yields are depressed. The application of B did not significantly change seed yields, but more research on B may be needed in areas where B availability is thought to be low.