INTERACTION OFCULTIVAR, SOWING DATE AND SOWING RATE ON LODGING, YIELD AND SEED WEIGHT OF BUCKWHEAT

Two buckwheat (Fagopyrum esculentum Moench.) cultivars, Tokyo and Tempest, were grown in 1971, 1972 and 1973 at 8.5, 17, 34 and 68 kg/ha sowing rates and at early, mid- and late June sowing dates. Tempest lodged more than Tokyo, particularly in 1971. Yield generally declined with each delay in sowing. In 1971, yield increased with each increase in sowing rate, while in 1972 there was no difference due to rate. In 1973, yield increased to the third rate and levelled out to the fourth. Therefore, a sowing rate of over 34 kg/ha may be required to assure good yields each year. Seed weight tended to decrease with delay in sowing but was not affected by sowing rate.