大麦不同播种密度和不同播种期叶面积动态及经济性状的表现

对沪麦4号6个不同播种密度、沪麦4号和舟麦1号7个不同播种期的各生育期叶面积指数及若干经济性状进行测定。结果表明,沪麦4号在土壤较肥沃的水田,各生育期群体叶面积指数以基本苗17.2万/亩处理最高,理论产量以基本苗13.0和17.2万/亩两处理较高;在土壤较瘠薄的旱地,群体叶面积指数则以基本苗21.6万/亩处理最高,理论产量以基本苗16.2和21.6万/亩两处理较高。在各播期中,早播群体发展较快。亩产量均随播种推迟而下降,且11月25日(沪麦4号)、11月5日(舟麦1号)以后播期的亩产量剧降。认为,在土壤肥力较低时,沪麦4号亩播量10kg,基本苗18～20万/亩为宜;土壤肥力较高时,亩播量应控制在5.0～7.5 kg,基本苗8～12万/亩范围。在南宁,沪麦4号播前期不应迟于11月下旬,舟麦1号不应迟于11月上旬。

DYNAMICS OF LEAF AREA AND ECONOMIC CHARACTERS IN DIFFERENT SOWING NORMS AND SOWING TIME FOR BARLEY

The leaf area indexes(LAIs)at different growth stages and some econom- ic characters were determined for six sowing norms of FB4 and seven sowing dates of FB4 and ZB1,respectively.The results showed that FB4 in the fertile paddy field,the LAI at each growth stage was the highest in the density of 172 000 seedlings per mu,and the theo- retical yields were higher in two densities,i.e.13000 and 172000 seedlings/mu,than those in other densities.In the poor upland field,the LAI at each growth stage was the highest in the density of 216000 seedlings per mu,and the theoretical yields were higher in densities 162000 and 216000 seedlings/mu than those in other densities.In date test,ear- ly sowing increased LAI quickly.The decrease of yield was accompanied with the delay of sowing,and only very low yield were recorded while sowing after 25 Nov.(FB4)and 5 Nov.(ZB1).It was regarded that the optimal seed quantity or density of crop population of FB4 was 10kg/mu or 180000-200000 seedlings/mu in lower soil fertility,and 5.0- 7.5kg/mu or 80000-120000 seedlings/mu in higher soil fertility.In Nanning,the optimal time for sowing should be before 25 Nov.for FB4 and before 5 Nov.for ZB1.