Study On Growth Redundancy And Control Measures Of Maize High - Yielding Populations

To find out different plant type of maize high-yielding growth redundancy of leaf and redundancy degree,then basis on this to explore control measures of leaf growth redundancy.This study selects three kinds of different plant type of high-yielding maize varieties in guizhou: compact-type corn Qianxing201, semi-compact-type corn Shundan6,flat-type Zhongdan808 as material.Planting in different densities and cutting different levels of leaf,researched effects of cutting leaf on yield and growth,and determine the redundancy degree of leaf. And by fertilization and regulator to regulate leaf growth.The main results were as follows:1 The relation between LAI on spinning tasseling stage and yield 2Qianxing201: Y =﹣380.42L2 + 4483.18 L- 2874.52-380.42, when LAI reached 5.91 yield is the largest;Shundan6: Y =-284.97 L2+ 284.97 + 518.38 L, it is most productive when LAI was 6.20;Zhongdan808: Y =-546.11 L2 + 546.11 + 518.65 L, it is most productive when LAI was 4.41.2 Effects of cutting leaf under different of densities on maize growth and yield① YieldQianxing201 under the 75000 plants/hm2 high density, not cut leaf and cutting 1/4 treatment have no significant difference, under 45000 plants/hm2 and 60000 plants/hm2, no cutting > cutting 1/4 > cutting 1/2 processing. Shundan 6 under density of 37500 plants/hm2, cutting 1/4 processing is significantly higher than no cutting, under density of 52500 plants/hm2, there is not significant difference between cut leaves a quarter treatment and not cut leaf, under 67500 plants/hm2 yield of cut leaf processing was significantly lower than not cut processing.Zhongdan 808 under the low density of 30000 plants/hm2 no cut leaf is significantly higher than leaf cut processing, under 45000 plants/hm2 and 60000 plants/hm2 higher density, cutting 1/4 processing and no cut treatment had no significant difference.② Photosynthetic performance.Chlorophyll relative content Ear-leaf chlorophyll relative content of 3 varietiesd after cuttng leaf of 15 d and 30,which influenced by the density is small, and 30 d is lower than 15 d. Modest cut leaf treatment and not cut leaf difference was not significant under a certain density, and sometimes higher than no cut processing.Photosynthetic rate and stomatal conductance 3 varieties under different density with different cut lesf processing,ear leaf photosynthetic rate and stomatal conductance changes are similar.After cutting leaf treatment, photosynthetic rate and stomatal conductance of 3 kinds of varieties was development.③ Accumulation of dry matter and NPKDry matter accumulation Dry matter accumulation of stem and spinke under different density, cutting leaf treatment and no cutting treatment was not significant, and under a certain density moderate shear leaf is beneficial to dry matter accumulation transfering to stem..The accumulation of NPK 3 varieties under different density, on the whole, through different cutting leaf processing, accumulation of N、P、K in stem and spink,not cut leaf treatment had no significant difference with cutting leaf treatment.④ Antioxidant enzyme activity and membrance peroxidationThe soluble protein content,SOD activity and POD activity, on the whole, cutting 1/4 processing and not cut cut treatment are no significant difference;while the MDA content in general will not significantly higher or lower because of the shear blade processing.3 Corn leaf growth redundancy and three kinds of plant type corn leaf growth redundancy Corn leaf growth redundancy is defined as: 100-100×effective photosynthetic LAI/maximum LAI, effective photosynthetic LAI refers to the maximum yield corresponded the minimum LAI.Leaf of three kinds of plant type maize existence growth redundancy,but the performance under the different density was different. Compact type Qianxing201 under 75000 plants/hm2 density, redundancy degree was 11.47%, Semi-compact type Shundan6 under the density of 37500 plants/hm2 and 52500 plants/hm2,the redundancy degree respectively were 21.67% and 5.14%,Horizontal type Zhongdan808 under the density of 45000 plants /hm2 and 60000 plants/hm2 redundancy degree were 20.20% and 22.34%.4 Effects of control measures on Qianxing201 yieldOn the basis of the fertilizer rate, by adjusting the fertilization ratio at different development stages, regulate the leaf growth, to increase production.Qianxing201 : Elongation stage fertilize N 20%, bell stage fertilize N 30%, spinning tasseling stage fertilize N 20%,which was beneficial to the improvement of the compact-type corn Qianxing 201 final yield.The regulator Huangjinyu growth regulating results on Qianxing201 is not obvious.