不同封闭期对上农四倍体黑麦草鲜草刈获量与产种量的影响

INFLUENCE OF DIFFERENT CLOSING DATES ON FRESH GRASS AND SEED YIELDS OF SHANGNONG TETRAPLOID RYE GRASS(Lolium multiflorum L.)

秋播上农四倍体黑麦草产种量的高低，受多个因素的影响。本研究在春后刈获一次鲜草的条件下，对５个不同封闭期进行比较，结果表明：为避免早春倒伏影响产种量，留种田都应刈获一次鲜草；早春适宜的封闭期应掌握在３月中旬黑麦草拔节前；若为获取更多鲜草量，在黑麦草拔节后再封闭．产种量将随封闭期的延后而迅速下降。

Seed yields of Shangnong tetraploid rye grass (Lolium multiflorum L.)areaffected by many factors. The influence of 5 different closing dates on yields of seeds andfresh grass cut once in spring was studied. Results from the experiment are as follows:1. The grass plants left to run to seed must be cut once to avoid plant lodging which willdecrease seed yield.2. The optimum closing date is during the second ten days of March before elongation.3. The seed yield is reduced sharply as the closing date is delayed until after elongation,though the fresh grass yield may be higher.