Study On Grain Filling And Dehydration Rate Of Suitable Maize Harvesting

With the increasing trend of Agricultural dualization,rural hollowing,and aging of farmers,the full mechanization of corn planting has become an inevitable trend.The mechanized corn harvest requires a proper maturity period of the corn and a low moisture content in the grain to ensure high and stable yield.Mechanized corn harvesting requires proper maturity and low moisture content of the grain.Grain dehydration rate and grain moisture content at harvest are important indicators for judging whether corn varieties are suitable for mechanized harvesting.Increasing grain dehydration rate and reducing moisture content are of great significance for cultivating suitable harvest varieties.In this study,12 maize inbred lines of early maturity,middle early maturity,middle maturity and middle late maturity were selected,and 6×6 incomplete double-row hybrid combinations were combined according to different maturity periods.Twelve backbone inbred lines and their hybrid combinations were analyzed for grain filling rate,dehydration characteristics,grain moisture content and combining ability at harvest,and their relationship with yield.The results are as follows.1.The results of corn grain filling characteristics research show that:(1)The grain filling rate of corn is a single-peak curve with S shape.The accumulation initiation potential and filling rate of early-maturing inbred lines are higher than other maturing periods,and the effective filling period is short,and the time to reach the maximum filling rate is early.(2)The theoretical maximum 100-grain weight of the inbred line J1590 is the largest,which is 32.15.JD212 has the advantages of a long active grouting period(26.34d)and a long effective grouting period(32.78d).(3)Early maturity(type hybrid)combination 6F576×PHGJ4 theoretical maximum 100-grain weight and maximum weight gain in each period,combination JD212×PH6WC has the longest active time of grouting;medium-early maturity combination TH23A×Z58 has the largest 100-grain weight and JD206×J1590effective grouting The longest duration of the period;the medium-combination combination J9D207×Z58 has the largest 100-grain weight and the longest duration of the effective grouting period of JD212×J1590;2.The research results of corn grain dehydration characteristics show that:(1)The water content of the early-maturing inbred lines began to decrease rapidly at 20 days after pollination,and the water content of the mid-early-maturing inbred lines decreased rapidly after 25 days of pollination.Both the mid-and late-maturing inbred lines continued to decline slowly.(2)The dehydration rate of the early maturing inbred lines is faster at 30-40 days after pollination,and the dehydration rate of the mid-early inbred lines is faster at25-35 days after pollination.The dehydration rate of the mid-to-late hybrids is 25-35days after pollination Faster.3.Yield performance and its correlation with grain filling rate and dehydration characteristics(1)Among the 36 hybrid combinations,the highest yield combination is J9D207×Z58(14950.6Kg/hm~2).The highest yield of the middle-mature group is 12550.53Kg/hm~2,and the remaining order is:middle-late-mature>middle-early-mature>early-mature.Therefore,the middle-mature type is selected for improvement,and it is easy to obtain a relatively high-yielding hybrid combination.(2)Correlation analysis results show that the grain filling rate of early-mature,middle-early-maturity,and middle-late-maturity hybrid combinations are significantly positively correlated with yield,and the medium-maturity hybrid combination is significantly positively correlated with yield.Dehydration rate is related to yield,and grouting rate is related to dehydration rate but not significant.4.Combining ability analysis of grain filling characteristics,dehydration characteristics and yield(1)The grouting characteristics Combining power shows that:the inbred line J1590 duration of grouting fast increase period,average rate of grouting fast increasing period,and general combining ability of maximum theoretical 100-grain quality are higher.The combination of TH23A×PHGJ4,JD205×J1590 maximum theoretical 100 The special combination of grain quality is high.(2)Combining power of dehydration characteristics showed that the dehydration rate of early maturing inbred lines 6F576 generally had the highest combining effect value,and the moisture content of the grain during harvesting generally had the smallest combining effect value.The maximum combination effect value of the combination of JD206×PH6WC grain dehydration rate is 12.38,and the minimum combination combination effect value of the combination of 6F576×KW5G321 and grain moisture content at harvest is-14.50.(3)Analysis of yield combining ability shows that:PHGJ4 output generally has a maximum combining ability effect value of 8.48,indicating that it has greater utilization value in increasing yield.The combination of J9D207×PH6WC and TH23A×PHGJ4 has a special combination with high output.