氮磷用量对杂种小麦C6-38/Py85-1群体生长及产量的影响

在大田条件下研究了不同氮、磷用量对杂种小麦群体生长及产量的影响.结果表明，在试验供肥范围内 (N112.5～337.5 kg·hm^-2，P₂O₅ 90～270 kg·hm^-2)，杂种的群体总茎数(PS)、群体干物重（PDW）、叶面积指数（LAI）、光合势（PP）和作物生长率（CGR）均以低肥处理低.高肥处理的PS和PDW高于中肥处理，高肥处理的LAI、PP和CGR分别于挑旗、拔节和开花期之前高于中肥处理，之后低于中肥处理.在低、中肥处理下，杂种各生育时期PS的离中优势（H_m）为负值，高肥处理冬前期、拔节期、开花期和成熟期分别为6.3％、49.7％、4.2％和10.8％；LAI的H_m除灌浆期中肥处理比高肥处理高3.8％、PDW的H_m除成熟期中、高肥处理间差异不显著外，其余各时期两性状的优势值高肥处理均极显著高于中肥处理；PP和CGR的Hm均以低肥处理最低,分别于拔节至挑旗期和挑旗至开花期之前高肥处理高于中肥处理，之后中肥处理高于高肥处理.杂种的籽粒产量及其H_m均以低肥处理最低，中肥处理的产量比高肥处理高216.2 kg·hm^-2;中肥与高肥处理之间产量的H_m差异不显著.

Effects of nitrogen and phosphorus application rate on population growth and grain yield of hybrid wheat C6-38/ Py85-1

This paper studied the effects of different nitrogen and phosphorous application rates (112.5-337.5 kg N x hm(-2) and 90-270 kg P2O5 x hm(-2)) on the population growth and grain yield of hybrid wheat C6-38/Py85-1 under field condition. The results showed that the total number of population stems (PS), population dry weight (PDW), leaf area index (LAI) , photosynthetic potential (PP) and crop growth rate (CGR) were the lowest under low fertilization rate (112.5 kg N x hm(-2) and 90 kg P2O5 x hm(-2)), PS and PDW were higher under high fertilization rate (337.5 kg N x hm(-2) and 270 kg P2O5, hm(-2)) than under medium fertilization rate (225 kg N hm(-2) and 180 kg P2O5 x hm(-2)), and LAI, PP and CGR were higher under high than under medium fertilization rate before flagging, jointing, and anthesis stage, respectively, but in adverse after these stages. Under low and medium fertilization rates, PS had no mid-parent heterosis (Hm), while under high fertilization rate, it had the positive values of 6.3%, 49.7%, 4.2% and 10.8% at before winter, jointing, anthesis, and maturing stages, respectively. The Hm of LAI and PDW increased significantly with increasing fertilization rate, except that the Hm of LAI was 3.8% higher under medium than under high fertilization rate at filling stage while that of PDW had no significant difference between these two fertilization rates at maturing stage. The Hm values of PP and CGR were the lowest in the whole growth period under low fertilization rate, and lower before jointing-flagging and flagginganthesis stage but higher after these stages respectively under medium than under high fertilization rate. The grain yield and its Hm of the hybrid wheat were the highest under medium fertilization rate, lower under high fertilization rate, and the lowest under low fertilization rate. The grain yield under medium fertilization rate was 216.2 kg x hm(-2) higher than that under high fertilization rate, but its Hm had no significant difference between these two fertilization rates.