Effects Of Cultivation Measures On Silique Shatter And Lodging In Rapeseed

In rapeseed production,silique shatter and lodging are the main factors causing yield loss.The experiments were conducted in the experimental field of Huazhong Agricultural University in 2014-2016,to study the effect of density,removal leaves and nitrogen,phosphorus,potassium,the 3 cultivation measures on silique shatter resistance index(SSRI),lodging index and yield components in rapeseed.1.The experiment was applied using three varieties(Zhongshuang 11,Huayouza 9hao and Huahang 901)and four plant densities(15 × 104 hm-2,30 × 104 hm-2,45 × 104hm-2and 60 × 104hm-2)to study the effect of densities on SSRI of difference branches and main stem,stem lodging site and yield.Results showed that:(1)With the increase of plant density,the SSRI decreased in main stems of Zhongshuang 11 and Huahang 901,while the SSRI increased firstly and then decreased with the increase of density in Huayouza 9 hao,the highest SSRI was at 300,000 plants hm-2.(2)The SSRI of the branches was smaller than that of the main stems.In the same density,the SSRI increased firstly and then decreased with decreased branch height;For the same branch,SSRI decreased with the increased density.In order to improve the accuracy of the SSRI identification,we should identify the SSRI of the siliques from the highest or lowest branch.(3)With the increased plant density,the plant height and branch height increased,while root crown diameter decreased,stem lodging site firstly increased and then decreased,with the highest value at300,000 plants hm-2 densities.(4)The yield of the three varieties reached the maximum at the planting density of 450 000 plants hm-2.2.In this experiment 0,1,3,and 5 green leaves were removed at the closure period,bud period and blooming period,using Huayouza 62.The SSRI related traits,lodging index,yield and yield components were evaluated.The results showed that:(1)The effective silique number per plant,the number of seed per silique,the 1000-seed weight and the yield was decreased after removal leaves in closure period and bud period;The effective silique number per plant was not significantly affected after removal 1 and 3leaves in blooming period,while the number of seed per silique,the 1000-seed weight and yield increased,when compared with the treatment without leaf removal(CK),removing 5leaves in blooming period increase the number of seed per silique and the 1000-seed weigh,but decreased the effective silique number per plant and the yield.(2)Leaves removal increased the weight of and water content the silique,and also affected the biochemicalcomposition of the silique,which can reduce the silique shatter.Removal 3 leaves in blooming period had the greatest effect on silique shatter resistance.(3)Leaf removal significantly reduced plant height,above ground fresh weight,root crown diameter and branch number,while significantly increased branch height,and stem lodging index.In rapeseed breeding,rapeseed varieties that leaves shredded early during the flowering can be cultivated to increase lodging resistance and shatter resistance.3.Varieties with different SSRI(Huashuang 5 hao,Huhang 901,Huayouza 62 and Fengyou 520)were used for N,P,K experimental material.The different fertilizers combinations of N(0,180 and 360 kg hm-2),P(0,120 and 270 kg hm-2)and K(0,150 and 300 kg hm-2),were applied to research the effect of N,P and K on yield and SSRI in rapeseed.The results showed that:(1)The amount of N,P and K had a significantly effect on the yield of four varieties,nitrogen fertilizer has the greatest impact on yield,and the yield was the highest at N2(360 kg hm-2).(2)The difference of SSRI among different varieties under N,P and K was significantly,and the SSRI of four varieties were as follows:Huahang 901>Huashuang 5 hao >Huayouza 62>Fengyou 520.(3)The treatments were divided into three groups: The four varieties obtained high shatter resistance under N2P1K1 and N1P1K1 combinations,middle shatter resistance under N2P0K1 and N2P1K2 combinations,and low shatter resistance under N0P0K1 and N0P0K2 combinations.(4)N,P,K treatment affected the silique shatter resistance index mainly by changing the dry weight of silique and lime lignin content.