高产棉花太阳辐射能利用率及干物质分配规律研究

通过对1988～1989年高产棉花栽培试验结果进行分析发现,棉花的太阳辐射利用率在叶面积系数小于2.0时随叶面积系数的增加而线性增加,大于2.0时增加变缓。从生育时间看,7月中旬前太阳辐射利用率指数上升,7月中旬至8月底相对稳定在1.2～1.4克/兆焦左右,9月以后又不同程度线性下降。生长季内子棉太阳辐射经济效率1988和1989年分别为0.14和0.15克/兆焦。收获指数与最大叶面积系数呈显著负相关;盛花期之前棉株各器官之间的同伸关系或明显,盛花期后器官的生长相互间无明显的确定性关系。如能调节密度与叶面积系数的关系,使得既提高5～6月的辐射能利用率,同时使7～8月叶面积系数维持在3.0～3.5的适宜范围内,9～10月群体又不早衰,则有利于获得高产。

STUDIES ON SOLAR RADIATION ENERGY-USE EFFICIENCY AND DRY MATTER PARTITION IN COTTON WITH HIGH-YIELD

Analyses on data of field experiment under high-yield cultural management in 1988 and 1989 showed that the solar radiation energy-use efficiency of cotton increased linearly with leaf area index (LAI) increased when LAI was below 2.0 and increased slowly when LAI was above 2.0. It meant that solar radiation energy-use efficiency increased in mid July, main- tained at 1.2 to 1.4 g/MJ untill the end of August and decreased linearly after September. The economic efficiency of solar radiation energy-use by seed cotton were 0.14 and 0.15g/ MJ within the season in 1988 and 1989, respectively. It also showed that the harvest index was significantly negative with the highest LAI during the growth season. Before the peak flower and boll-forming stage, the organs of plant showed a significant coherent growth and there were no obviously determinate relationships between organ development after flower and boll--forming stage. If the relation between plant density and LAI are adjusted to make the solar radiation energy-use efficiency in May and June increase, and LAI are maintained at 3. 0 to 3.5 during July and August, and the plant population are kept not getting early senes- cence, the high yield will be obtained.