The Study Of High-Efficient Pod Canopy Of Oilseed Rape

The experiments were carried out on the experimental field of crop cultivation and physiology key laboratory,YanZhou University from 1999 tolOOl.The effects of nitrogen,fertilizer and density were studied.and the distribution of pod number,seed number per pod,1000-seed weight,pod weight in space of different type pod canopy were studied,hybrid rape (Brassica napus L) Qingyou No.2 and double-low hybrid (Brassica napus L) Ningyou No.l as material.The change of the productivity per pod area (PPA),the component of main raceme and branches ,the difference of starting and terminating pod of all branches.The main results were as follows:1. Analyzed the relation of starting and terminating pod of branches and their yield of different type pod canopy,made clear that the starting and terminating pod of high efficient-pod canopy should be uniform.2. The pod qualities in different layers were different.In upper 30cm space of efficient pod canopy.the proportion of invalid pods were less, large and medium pods were more.seed number per pod was more, seed number per pod of high layers had fewer difference, 1000-seed weight and PPA was high.The experiment showed that if pod in upper 30cm spaces were up 65%,they often acquired high yield.3. The secondary branches should be properly increased basied on morderate total numbers of main raceme and branches and steady numbers of primary branches.In this experiment,the moderate total numbers of main raceme and branches were 180000-200000,the main raceme,primary branches and secondary branches were6500-7500,800000-900000,900000-1000000.4. The relative of starting and terminating pod of the main raceme and each branches is a important indices.The productivity of all brnaches was significanty positively related to the starting and terminating pod.The branches with high starting and terminating pod lay in the middle and upper layers can receive better light.They had high productivity and often became high-efficient branches.The productivity of a high-effective btanch made up 7% of whole or more.The starting pod of high-efficient effective branches should be higher than the main raceme ,and the terminating pod below the main raceme should be not go beyond 10-15cm.If the starting and terminating pod of all branches were high,the proportion of high effective branches were large.the photosynthetic efficiency of total pod canopy was high too.