不同生育期温光条件对直播稻产量的影响

在江苏苏南太湖稻区的常熟市(N 31.4°)、苏中里下河稻区的姜堰市((N 32.3°)及苏北淮北稻区的东海县(N 34.5°),分别以不同类型粳稻品种为材料,通过分期播种试验,比较研究不同生育期温光条件对江苏上述不同生态区直播稻产量的影响。结果表明,在本研究设置的播期范围内,随着播期的推迟,各生态区不同熟期类型品种水稻的产量均呈极显著下降趋势,但变化程度略有不同,表现为晚熟品种大于早熟品种,过迟播种导致各生态区部分类型品种不能安全成熟。产量构成因素随播期的推迟按变化程度的大小分为两类,变化较小的一类为千粒重和穗数,变化较大的一类为结实率和每穗颖花数,后者是导致产量极显著下降的主要原因。总颖花量、结实率和产量与抽穗前以及全生育期的积温和光照时数呈显著或极显著相关,各生育期温光条件对千粒重的影响不显著。

EFFECTS OF TEMPERATURE AND SUNLIGHT CONDITIONS ON THE YIELD OF DIRECT SEEDING RICEIN DIFFERENT GROWTH STAGES

Taking late-maturing medium japonica rice, early-maturing late japonica rice and medium-maturing late japonica rice in Taihu rice district in Changshu (south of Jiangsu province, N 31.4?), medium-maturing medium japonica rice, late-maturing medium japonica rice and early-maturing late japonica rice in Lixiahe rice district in Jiangyan (middle of Jiangsu province, N 32.3?),early-maturing medium japonica rice, medium-maturing medium japonica rice and late-maturing medium japonica rice in Huaibei rice district in Donghai (north of Jiangsu province, N 34.5?) as experimental materials, the effects of temperature and sunlight conditions on the yield of direct seeding rice in different growth stages and different ecological regions of Jiangsu were comparatively studied by the test of sowing date. The results showed that in the sowing date set in the study, when the sowing date delayed, the yields of direct seeding rice of different maturity typein different ecological regions reduced very significantly,and the difference of changing degree different with late-maturing varieties was higher than that with early-maturing varieties, and in three ecological regions some types could not mature when the sowing date was too late. The changing degree of yield components along with the delayed sowing date could be divided into two groups that the group with small changes was 1000-grain weight and panicles, and the other was spikelets per panicle and filled grain percentage which was the main reason of yield reducing. It showed significant or very significant correlation between total spikelets, filled grain percentage, yield and accumulated temperature and illumination hours of whole growth stages, the effect of temperature and sunlight conditions in different growth stages on 1000-grain weight was not significant.