连作杂交晚稻精准条播长秧龄机插的生长及产量特性分析

为明确精准条播(precision drill sowing, PS)在连作晚稻长秧龄机插中的有益效果。本试验以甬优1540为供试品种,设置标准9寸秧盘横向16条(PS-16, 45.7 g盘^–1)和18条(PS-18, 60.5 g盘^–1)精准条播,并以传统撒播(broadcast sowing, BS, 60.5 g盘^–1)作为对照,同期播种,设置20、25、30和35 d 4个机插秧龄,比较分析各播种方式水稻秧苗素质、机插特性、群体生长及产量形成的变化。结果表明:(1)精准条播提高秧苗群体透光性,与撒播相比,精准条播提高了长秧龄秧苗的素质,增加了带分蘖秧苗的比例,其中PS-16秧苗素质最好,带分蘖秧苗的比例最高。(2)与撒播相比,精准条播显著降低机插漏秧率,提高机插取秧2～3株苗比例,PS-16和PS-18间差异不明显。秧龄延长增加机插秧苗伤根程度和伤苗率,降低秧苗存活率,其中PS-16的伤根程度和伤苗率增加幅度最小,机插秧苗存活率最高。(3)机插秧龄延长增加了秧苗缓苗返青天数进而推迟水稻生育期,各机插秧龄下, P...

Analysis on the plant growth and yield formation of double cropping late sea-son hybrid rice in machine transplanting with long seedling age by precision drill sowing

In order to ascertain the beneficial effects of precision drill sowing(PS)in machine transplanting with long seedling age of double cropping late season hybrid rice.In this study,seed of Yongyou 1540(YY1540)was subjected to precision drill sowing of 16 rows(PS-16,45.7 g tray^-1),precision drill sowing of 18 rows(PS-18,60.5 g tray^-1)and traditional broadcast sowing(BS,60.5 g tray-1)in standard seedling tray at the same day.Seedling ages of 20,25,30,and 35 days were set for machine trans-planting to analyze the rice seedling quality,machine transplanting characters,rice population growth,and yield formation be-tween PS-16,PS-18,and BS.The results were as follows:(1)PS improved the light transmittance of seedling population,com-pared to BS,PS enhanced the seedling quality and increased the percentage of seedlings with tillering buds,among the treatments,PS-16 got the best seedling quality and highest percentage of seedling with tillering buds.(2)Compared to BS,PS significantly reduced the missing hill percent and increased the ratio of hills with 2-3 seedlings transplanted,and there was no significant dif-ference between PS-16 and PS-18.Seedling age prolonging increased the root injury degree and seedling injury rate,and de-creased the seedling survival rate after machine-transplanting,in which,PS-16 had the minimal increasing in root injury degree and seedling injury rate,meanwhile PS-16 got the highest survival rate of seedling machine-transplanted.(3)The seedling age prolonging postponed the rice growth duration by increasing the duration of seedling rejuvenation period.Among the seedling age treatments,the shortest period of rejuvenation period was observed in PS-16,and then the growth period minimal delayed in PS-16 with the seedling age prolonging.(4)PS effectively promoted plant tillering,and PS-16 got the best effect.The number of tillers at 10 d after machine transplanting of PS-16 machine was 16.4%and 20.8%higher than that of PS-18 and BS,in average.Seedling age prolonging decreased the tiller number at tillering peak stage,and the tiller number at tillering peak stage was PS-16>PS-18>BS at different seedling age treatments.The productive tiller percentage presented no difference among the sowing methods and seedling ages.(5)Seedling age prolonging decreased the leaf area index and dry matter accumulation by the degree of PS-16PS-18>BS under different seedling age treat-ments,in average.In conclusion,compared to BS,PS could improve the seedling quality,reduce the missing hill percentage in machine transplanting,improve the machine transplanting quality,shorten the seedling rejuvenation period,promote plant tillering,and increase the leaf area index and dry matter accumulation,and then effectively reduce the yield loss of double late season hy-brid rice with long seedling age in machine transplanting,and the benefits of PS-16 were better than that of PS-18.