Interaction Effects of Density and Pruning on Spatial and Temporal Distribution of Bolls of SCRC 28

Li Haitao; Yang Zhongxu; Li Qiuzhi

doi:10.14083/j.issn.1001-4942.2016.09.010

Abstract：Insect -resistant cotton general fine pruning usually results in serious premature aging and low labor efficiency.Under the condition of low density,the cotton plant is tall and loose,the boll number per plant was high and that per unit area was low.The cotton plant is short and tight under the condition of high density,and there are many rotten bolls at the bottom.In this study,the effects of different densities and pruning methods on spatial and temporal distribution of bolls of SCRC 28 were researched by split plot experi-ment design.The results showed that under the condition of low density,the total number of pre -summer bolls,summer bolls,early autumn bolls and late autumn bolls was obviously higher than that under the high density condition,and the difference was significant.For different pruning methods,the bolls mainly formed in summer and early autumn.The number of summer bolls and early autumn bolls of simplified pruning treat-ment was slightly less than that of other treatments.With the increase of density,the roll number on the low-er,middle and upper layers of cotton plant decreased on different levels.The interaction of density and prun-ing had bigger influences on the longitudinal distribution of bolls.The higher the density,the less boll number on the lower layer of cotton plant under fine pruning and simplified pruning treatment.In the density range of (30 000 ~45 000)plants/hm2 ,the boll number on the lower layer of cotton plant under open -centered pruning treatment showed the trend of firstly increased and then decreased.The change of density had little in-fluence on the horizontal roll forming under different pruning treatments.When SCRC 28 was cultivated in density of 30 000 plants/hm2 with open -centered pruning method,the boll distribution on time and space was more reasonable,and it was more likely to form high quality bolls and improve the level of cotton.