Study On The Introduction And High-Yield Cultivation Techniques Of American Spring Maize Varieties Suitable For Harvest

Maize has become the first grain crop in our country.With the shortage of rural labor force and the rising cost,it is very important to raise the harvest level of spring maize and select and introduce some varieties suitable for mechanized harvest.In order to prevent the extension of maize mechanical harvest due to the lack of suitable harvest resources and variety selection and evaluation system in China,in this study,11 n spring maize varieties and 7 domestic spring maize varieties suitable for mechanical harvesting were selected from three aspects: mechanical harvesting,water-tight interaction and ecological adaptability,through the investigation and analysis of agronomic traits,stem strength,mechanical grain harvest quality,physiological and biochemical indexes and yield,the varieties were comprehensively screened and evaluated.The main findings are as follows:(1)There was a significant positive correlation between yield and ear drop rate and yield loss rate in 18 spring maize varieties during mechanical grain harvest,there was a significant negative correlation between grain moisture content,crushing rate,impurity rate and falling rate.The piercing strength,crushing strength and bending strength of the same maize plant stem decreased with the increase of above-ground joints.The varieties19251,19351,16092,14007,S57 × S79,S81 × S59-1,19569 showed good yield,leaf area index,dry matter accumulation,agronomic traits,lignin,cellulose,hemicellulose content and SPAD value,it can be further studied in Inner Mongolia.(2)The grain yield was significantly decreased under moderate water stress and high density,and the effect of moderate water stress was greater than that of high density.Under normal irrigation with M 5 level,the yield of 19251,19351,16092,14007,S57 × S79,dika159 and KWS9384 were lower than that of M 8.Under normal irrigation with M 8 level,the yield of 19251,19351,16092,14007,S57 × S79,dika 159 and KWS9384 were lower than that of M 8,the yields of S58 × S79,S61 × S79,S59 × S79,S81 × S59-1 and 17237 were lower than those of M5.Under moderate stress,the SPAD values of all varieties showed a decreasing trend,and under high density planting,the decreasing range of SPAD values was less than that under water stress.The content of lignin and cellulose in the third internode of stem base increased with the increase of planting density,while hemicellulose content decreased with the increase of planting density.The soil bulk density of normal irrigation area was lower than that of drought stress area.Under the same water gradient,the soil bulk density of the same variety at M5 level was higher than that at M8 level.The order of varieties selected in two years was: 19251 > 19351 > 16092 > 14007 > deca 159 >KWS9384.(3)The total yield and dry matter accumulation of the four ecological regions were as follows: Chifeng,Wuyuan,Sarazzi,Jalaid Banner.The varieties with good ecological adaptability were 19251,16092,14007,19351.The varieties with middle ecological adaptability were S81 × S59-1,dika 159,S57 × S79,KWS9384,17237.The ecological adaptability of S58 × S79,S61 × S79 and S59 × S79 was poor.