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后季稻的有效分蘖期短,幼穗分化期短,依靠分蘖争足穗或主攻大穗,都受到客观条件的限制。因此,保证密度插足基本苗数,就成为争多穗,夺取平衡增产的中心环节。近年来,后季稻的产量一直徘徊在六、七百斤水平。上海郊区以晚粳类型品种当家,穗大粒重,对增产是有利的。一般的每穗实粒数在40粒以上,千粒重可达27克左右。可是,有效穗数偏少,只有30万左右,严重影响后季稻产量的进一步提高。后季稻有效穗数不足,原因是多方面的,由于秧苗素质差、肥料施不足、插秧过深以及季节拖得过晚等因素造成稻亩晚发,致使早期分蘖少,分蘖成穗率不高。而更重要的
The effective tillering stage of late rice is short, and the differentiation of young panicles is short. It is limited by the objective conditions to rely on the ability of tillers to fight the spikes or the main big spike. Therefore, to ensure that the density of seedlings inserted into the basic number, it has become a multi-spike, to win the balance of the central part of production. In recent years, the output of post-season rice has been hovering at the level of six or seven hundred pounds. Shanghai suburbs to the type of late japonica varieties, spike large grain weight, is conducive to yield. The average number of grains per panicle in more than 40, 1000 grain weight up to 27 grams. However, the number of effective spikes is small, only about 300000, seriously affecting the further improvement of the yield of the latter part of rice. The number of effective panicles after the late rice is insufficient for many reasons. Due to poor quality of seedlings, inadequate fertilizers, excessive transplanting, and too late seasons, the number of late panicles is so low that the number of early tillers is small and the rate of tillering is not high. And more important