播种期、秧龄及施氮量对杂交粳稻春优84产量及生产特性的影响

摘要

Field experiment was conducted using Chunyou 84 ( Oryza sativa,japonica) with five sowing dates ( May 10th,20th,30th and June 9th,19th), five seedling age (20,25,30,35 d and 40 d) and nitrogen fertilizer levels (150.0, 187.5, 225.0, 262.5 and 300.0 kg N· hm-2) to study the effects of different sowing dates, seedling age and nitrogen rates on cumulative rates of dry matter , main agronomic characters and yields .The objective of the experiment is to clarify the related high-yield cultivation techniques of hybrid japonica rice Chunyou 84 in Jinhua and provide technical support and theoretical basis for high-yield cultivation .The results showed that along with the delaying of sowing dates , the growth process of Chunyou 84 was correspondingly delayed , growth stages were significantly shortened .The yield of Chunyou 84 was the highest when the sowing date was on May 10th, the decreasing range of yield increased with the delaying of sowing date .The yield of Chunyou 84 was the highest when the seedling age was 20 d, the yield remarkably declined after the seedling age of 25 d.When the seedling age increased, the spikelets number per panicle and the number of effective panicles of Chunyou 84 decreased.The dry matter distribution in panicles significantly declined as the increasing of nitrogen application at the maturity stage . The results indicated that the N 4 treatment got less dry matter distribution in panicles and yield than the N 3 treatment, which indicated that excessive nitrogen application was not helpful for raising the grain field .The reasonable sowing date for Chunyou 84 as single cropping late rice was May 10th-20th,proper early sowing date was helpful for raising the yield .The optimal seedling age that Chunyou 84 can get higher yield was in the range of 20-25 d, the yield significantly decreased after the seedling age of 25 d.The optimal N application for Chunyou 84 was 262.5 kg N· hm-2 , the excessive N application decreased the yield .%以杂交粳稻春优84为材料，通过播种期（5月10日、5月20日、5月30日、6月9日、6月19日）、秧龄（20，25，30，35，40 d）和氮肥（150.0，187.5，225.0，262.5，300.0 kg N· hm-25个氮素水平）多因素试验，研究不同播种期、移栽秧龄和氮素施用量对春优84各生育期干物质累积、产量及产量构成因子的影响。结果表明：春优84随着播种期的推迟生育进程相应推迟，生育期缩短，在5月10日播期产量最高，随着播种期推迟减产幅度加大；春优84在20 d秧龄产量最高，秧龄超过25 d产量显著下降，秧龄增加会降低有效穗数和每穗粒数，导致产量降低。春优84的秧龄弹性较大，可作为连作晚稻种植的潜力；增施氮肥有利于提高春优84成熟期干物质在穗部的分配比例，施氮量过多导致穗部干物质分配比例下降，产量降低。春优84在金华地区作单季晚稻种植的适宜播种期为5月10-20日，适期早播有利于产量提高，移栽秧龄以20～25 d为宜，超过25 d产量减产明显，最佳施氮量为262.5 kg N· hm-2，过量施氮容易导致减产。