Effects Of Maize Roborant And Uniconazole On Plant Height And Yield Of Hybrid Maize Zhenghong 311

With Hybrid Maize Zhenghong311 as materials,in the low altitude region Ya'an(600m),high altitude region Xichang(1590m).Studies were conducted on the effects of maize roborant and unicoazole on plant height,ear height,accumulated amount of dry matter and yield,in the early jointing stage and small bell-mouth stage,with differdnt concentrations,and the relation among the plant height,ear height,accumulated amount of dry matter and yield.The results were as follows:1.Maize roborant and uniconazole applied at early jointing stage and small bell-mouth stage had certain effects of reducing plant height and ear height.The decreasing amplitudes were differdent,because of the kinds of plant growth regulators,applied time,concentrations and places of cultivation.Overall,the effects of reducing height of maize roborant were more remarkable than that of uniconazole.The effects of reducing height of small bell-mouth stage were more remarkable than that of early jointing stage.The effects of reducing height of high concentration were more remarkable than that of low concentration.The effects of reducing height of Ya'an were more remarkable than that of Xichang.2.The grain yields were decreased,because maize roborant and uniconazole applied at early jointing stage had removed the growth of stems and leaves and reduced the plant height and ear height.The concentration thicker,the yield lower.The main reason of yield reducing in Ya'an was the reduction of thousand-grain-weight.That of Xichang was the reduction of row number per ear.Yield reduced by maize roborant applied at small bell-mouth stage in Xichang.But yield increased by maize roborant applied at small bell-mouth stage in Ya'an,because of lower plant height and lodging less.3.In Ya'an and Xichang,the SLA,LAR and LAI increased.But the LWR and accumulated amount of dry matter per maize reduced.Those means the photosynthesis of maize leaf will reduce by applying maize roborant and uniconazole unreasonably,which is the physiological basis of effects of maize roborant and uniconazole on the yield.4.The results mean that there was a certain environmental effect in the effects of maize roborant and uniconazole on plant height and yield.Maize roborant and uniconazole shall be applied in line with the local conditions.In Ya'an,spraying 1.5mg/l maize roborant at small bell-mouth stage can offer protection from lodge,because of higher plant.In Xichang,there is more sunshine,and plant is lower to Ya'an.So there is no need to apply maize roborant and uniconazole only if the place can make maize overgrow.In this case,spraying 1.5mg/l maize roborant is right.5.With different ecological environment,the compositions of yield in Ya'an and Xichang were different.In Ya'an,compared with Xichang,there were bigger row number per ear,smaller thousand-grain-weight and grain number per row.Its direction of high yield was increasing the thousand-grain-weight and grain number per row to promote its grouting.That of Xichang was increasing the row number per ear and grain number per row.