Boron nutrition of perennial ryegrass, cocksfoot, and timothy

摘要

Abstract Perennial ryegrass (Lotium perenne L.), cocksfoot (Daclytis glomerala L.), and timothy (Phleum pralense L.) were grown in pots with 7 rates of boron (B) to determine if deficiency or toxicity developed in these grasses. No yield response or deficiency symptoms occurred even though B concentrations were only 6-12 ppm in the control plants. B toxicity symptoms occurred at high application rates in ryegrass and timothy for 3 cuts and cocks foot for 2 cuts. Timothy yields were reduced by B toxicity for 2 cuts but ryegrass and cocksfoot yields were reduced only at the first cut. Ryegrass and timothy plants had toxicity symptoms when they contained more than 39-42 and 47 ppm B respectively. It was not possible to establish a precise threshold value for cocksfoot but it was between 34 and 63 ppm B. It is concluded that if B is required for the clover component of established pastures there will be no detrimental effect on the grasses at the recommended application rate.