杂草防除对双季直播优质晚籼稻产量和稻米品质的影响

为了探明杂草防除对双季直播优质晚籼稻产量形成和稻米品质的影响，以优质常规稻美香占2号（MXZ2）和优质杂交稻泰优871(TY871)为材料，设置化学除草剂除草（CW）和不除草（NW）2种处理。与NW处理相比，CW处理下MXZ2和TY871分别增产75.71%和76.00%，增产原因主要是有效穗数和穗粒数显著增加。与NW处理相比，CW处理总体能够改善直播稻的加工和外观品质，且胶稠度显著降低7.65%～8.03%。CW处理显著提高直播晚稻稻米淀粉峰值黏度、热浆黏度、崩解值和最终黏度，消减值显著下降，提升了稻米的适口性，而NW处理显著降低了MXZ2的回复值，对垩白粒率、直链淀粉和蛋白质含量无显著影响。总体来说，化学除草剂除草显著提高直播优质晚稻的产量，对直播优质晚稻的加工品质有显著改善作用，同时降低稻米垩白度和胶稠度。此外，化学除草显著影响稻米淀粉RVA谱特征值，有利于蒸煮与食味品质的改善。

Effects of Weeds Control on the Yield and Quality of Double- Cropping Direct-Seeded High-Quality Late Indica Rice

In order to investigate the effects of weeds control on the yield formation and quality of double- cropping direct-seeded high-quality late indica rice, high-quality inbred rice Meixiangzhan 2 (MXZ2) and high- quality hybrid rice Taiyou 871 (TY871) were used as materials, the field experiment with two treatments of chemical herbicide weeding (CW) and non-weeding (NW) were conducted. Compared with NW treatment, the grain yields of MXZ2 and TY871 under CW treatment increased by 75.71% and 76.00%, respectively, mainly due to the significant increase in the effective panicles and the spikelets per panicle. Compared with NW treatment, CW treatment could generally improve the processing quality and appearance quality of direct-seeded rice, and the gel consistency significantly reduced by 7.65% and 8.03%, respectively. CW treatment significantly increased the starch peak viscosity, hot viscosity, breakdown value and final viscosity of direct-seeded late rice, decreased the setback value, and improved the palatability of cooked rice. However, NW treatment significantly reduced the consistence of MXZ2, and did not differ on the chalkiness grain rate, amylose content and protein content. In all, spraying chemical herbicides for weed control significantly increased the yield of direct-seeded high-quality late rice, and it could significantly improve the processing quality of direct-seeded high-quality late rice, while reduced the chalkiness and gel consistency of rice. In addition, chemical weed control significantly affected the values of rice starch RVA profiles, which was beneficial to the improvement on cooking and eating quality.