Selection Of Fresh Maize Varieties For Soybean Corn Strip Co Mpound Planting

The soybean and corn belt composite planting technology has been piloted in China for many years,with more than 467,000 hm2 planted in the country,and the planting mode and planting technology are relatively mature.It can promote the sustainable development of fresh corn industry to clarify the quality of fresh corn under soybean-corn strip compound planting.In this experiment,12 fresh corn varieties and soybeans,CN1,WN1,WN6,AZ60,WN11,WN2018,WN2000,WN12,TYM,L-1,L-2and BY1,which were mainly planted in Northwest Hebei,were used as experimental materials.According to the row ratio of corn to soybean 2:4.Intercropping,compared with fresh corn monocroping,studied the plant performance of different fresh corn varieties and soybeans,and analyzed crop yield,yield components and advantages of intercropping.The main research results are as follows:1.The growth period of 12 fresh food maize varieties was between80～102d,and the effective accumulated temperature during the growth period was between 1026.4～1289.3℃·d,all of which could be planted and harvested normally in northwestern Hebei.The seeding-emergence time of each variety was 13-16D,the seedling emergence of BY1 was the earliest,and that of TYM was the latest.There was a big difference in the time between emergence,jointing and tasseling.L-1 needed only 12 days from jointing to tasseling,while WN2018 and WN2000 needed 26 days.The silk-harvest time of each variety was between 21 and 28 days.TYM,L-1,L-2,BY1 were early maturing varieties（80～85d）.CN1 was a medium ripe variety（89 d）.WN1,WCN6,AZ60,WN11,WN2018,WN2000 and WN12belong to the late maturing varieties（96～102d）.The yield of late maturing varieties was higher,and the plant performance was better than that of middle and early maturing varieties.2.In terms of agronomic characters,the plant height of each variety from seedling stage to harvest stage was 18.37～298.10 cm under strip composite planting,WN2000 was the highest and L-1 was the lowest.Stem diameter from seedling stage to harvest stage was 0.74～3.05cm,among which WN2018 and WN2000 had the largest stem diameter,followed by WCN6,and L-2 had the smallest stem diameter at harvest.The leaf area index from seedling stage to harvest stage was 2.82～13.50.LAI of all varieties at seedling stage-jointing stage-tasseling stage showed an increasing trend under strip composite planting,and LAI from jointing stage to tasseling stage was the fastest increasing period of leaf area index.From tasseling stage to harvest stage,LAI of TYM,L-1,BY1 and WN14 all varieties began to decline,while LAI of other varieties still showed an upward trend.In terms of photosynthetic characteristics,WN1,WCN6,WN2000 and WN2018 among the 12 fresh food maize varieties had higher SPAD value,Pn,Tr and Gs,but lower Ci,which showed better photosynthetic performance than other varieties.3.In terms of quality,the soluble sugar content of different varieties under strip composite planting ranged from 3.32%to 22.27%.The soluble protein content was between 4.76 and 7.56 mg·g^-1.Starch content ranged from 20.42%to 67.35%.The content of soluble sugar in the grains of fresh maize varieties was between 6.07%and 16.41%.The soluble protein content was 6.14-8.94 mg·g^-1.Starch content was 24.79%～70.56%.The contents of soluble sugar,soluble protein and starch in the grains of WN1,AZ60 and WN2018 were high,which were 8.35%,7.62mg·g^-1and60.71%,respectively.Therefore,WN1,AZ60 and WN2018 had the best comprehensive traits of quality.4.The grain yield of soybean and corn in intercropping was significantly lower than that of control than that of soybean and corn in monoculture.The yield of fresh fruit ear in WN1,WN2018 and WN2000was higher,reaching 13978.83 kg·hm^-2on average.4.The indexes of edible ear and straw feeding quality of fresh maize were evaluated by systematic cluster analysis,and three varieties WN2000,WCN6 and WXN2000 with the best edible quality and two varieties WCN6 and WXN2000 with the best feeding quality were selected.The comprehensive evaluation results were more accurate and had practical significance for variety screening.In conclusion,WN1 and WN2018 varieties of fresh corn had good plant performance,excellent quality and yield,and were suitable to be used as soybean-fresh corn zonal compound planting in northwest Hebei Province.