不同生育期干旱对水稻生长和产量的影响

EFFECTS OF DROUGHT ON RICE GROWTH AND YIELD IN DIFFERENT GROWTH STAGE

盆栽条件下研究了干旱对晚稻生长和产量的影响。结果表明,各生育期不同程度干旱都会影响水稻产量,减产最大的时期是孕穗期(53.3～67.4％)和灌浆期(35.2～54.8％),为水稻的需水临界期,但孕穗期短期干旱(断水10天)在所有处理中减产最少;生殖生长期干旱明显降低颖花分化,增加颖花退化和小穗不实,分化期干旱还显著延迟生育进程,分化期断水20天,延迟抽穗13～15天,灌浆期干旱导致植株早衰、灌浆不完全,结实率和千粒重显著降低;分蘖期干旱对产量影响相对较小,但明显抑制分蘖发生,降低有效穗10～30％。文中还讨论了孕穗期需水特点和干旱延迟抽穗对晚稻的不利影响。

The effects of drought on the growth and grain yield of late season rice were studied under pot condition. The results indicated that: drought stress occured at any growth stage would reduce the rice grain yield, yield loss were greatest when drought stress were imposed at booting and filling stages (33.3~67.4% and 35.2~54.8% respectively), but a short time diought (10 days without watering) at booting stage resulted in least yield loss in all treatments, At reproductive stage, drought stress significantly reduced the spikelet differentiation and caused large amount of spikelet degeneration and sterility, postponed the panicle development process especially at differentiation stage, when water was withdrawn after 20 days, the heading would be delayed by 13~15 days, Drought stress occured at filling period led to precocity of the plants, sparing grain, and a decrease of the setting percentage and 1000-grain weight, the g;ain yield was recuced less water stress occured at tilling stage, but the tilling was severely inhibited and the panicle numbers plant were reduced 10~30%, The characteristic of water demand at booting stage and the adverse effects of drought on delaying headig in late season rice were also discussed.