EFFECTS OF GIBBERELLIN ON FORAGE YIELDS OF SIX GRASS AND LEGUME SPECIES

Abstract

Foliage of three grasses and three legumes, grown in a greenhouse, was treated with gibberellin solution and yield response evaluated. In general, the first cut yields of these grass and legume species were increased by gibberellin. With legumes the maximum yields were obtained at the highest rate of application. Maximum yields of grasses were obtained with rates less than the highest. Generally speaking there were reductions in second-cut yields of the grasses and legumes tested with higher rates of gibberellin. Treatment of the foliage with gibberellin decreased root weights m every case.There were significant negative correlations between total top and root weights of all species, except two in which there were no correlations. The per cent protein of all grass and legume species was decreased with gibberellin treatments. However, because of increased dry matter, highest yields of protein were generally obtained with treatments producing highest dry matter yields. The per cent ground cover of the species treated decreased progressively with increased rates of gibberellin.