Effect Of Different Plant Growth Regulators On Yield And Agronomic Traits Of Maize

Effects of spraying periods and spraying concentration of5different plant growth regulators (JinDele, Dun Tianbao, Kangmei, Yi Xili and Kang Fengli) on Photosynthetic characters, morphologicalindexes and yield of thin planting, big ear-type hybrid maize Liaodan526, Liaodan145and Liaodan527were studied. The results showed as below:一Effect study of plant growth regulators at different spraying periods1Trial designPlanting densities of three hybrids were all4000per mu and regulating periods of5plant growthregulators were leafage6, leafage9and leafage12in the test. Spraying concentration was accordancewith the recommended standards by the manufacture.2Morphological indexesPlant height and ear height of Liaodan526were decreased at Dun Tianbao, Yi Xili and KangFengli treatments. Stem diameter of Liaodan526was thickened by using Jin Dele, Dun Tianbao, Yi Xiliand Kang Fengli, and length of node of that at base was shortened by using that4chemical regulators.Compared with ck, the plant height and ear height of Liaodan527were decreased by using chemicalregulators except Kangmei treatment. While stem diameter of Liaodan527was thickened by usingKangmei, and length of node of that at base was shortened by using that chemical regulator. Comparedwith ck, plant height and ear height of Liaodan145were decreased by spraying chemical regulators.Stem diameter of Liaodan145was thickened by using Jin Dele, and length of node of that at base wasshortened by using that plant growth regulator.3Photosynthetic rate and LAIThe results showed Photosynthetic rate (Pn) and LAI of ear leaf of Liaodan526, Liaodan145andLiaodan527were increased by spraying plant growth regulators at seed filling stage. The highest valuesof Pn and LAI of ear leaf of Liaodan526were using Yi Xili at leafage12. The highest values of Pn andLAI of ear leaf of Liaodan145were using Kang Fengli at leafage6and9, respectively. The highestvalues of Pn of ear leaf of Liaodan527were using Jin Dele at leafage6.4Yield componentsYield data showed that Kangmei and Jin Dele would improve yield significantly in suitablespraying period of5plant growth regulators. yield of Liaodan526was increased significantly byspraying Kangmei plant growth regulator at leafage9(the proportion was15.5%), that of Liaodan145was increased significantly by spraying Kangmei plant growth regulator at leafage6(the proportion was15.5%), and that of Liaodan527was increased more by spraying Ji Dele plant growth regulator atleafage6(the proportion was16.6%).二Effect research on chemical regulators at different spraying doses1Trial designPlanting densities of5hybrids were all4000per mu and regulating periods were leafage9,6concentration gradients were0ml per mu(ck),20ml per mu,25ml per mu,30ml per mu,35ml per muand40ml per mu of5plant growth regulators in the test. 2Morphological indexesPlant height and ear height of Liaodan526, Liaodan145and Liaodan527were decreased withdose of plant growth regulator increased except Kangmei treatment. Length of node of Liaodan526atbase was shortened with dose of Dun Tianbao increased. Stem diameter of Liaodan145was thickenedwith doses of Yi Xili and Kang Fengli increased, and length of node of that at base was shortened withthat. Length of node of Liaodan527at base was shortened with doses of Jin Dele and Kang Fengliincreased.3Photosynthetic rate and LAIThe results showed Pn of ear leaf of Liaodan526, Liaodan145and Liaodan527was expressedincreased first, then decreased with dose of plant growth regulator increased.4Yield componentsYield data showed that yield of Liaodan526was increased significantly by spraying Kangmeiplant growth regulator at20ml666.7m-2(the increased proportion was13.9%), that of Liaodan145wasincreased significantly by spraying Kangmei plant growth regulator at35ml666.7m-2(the increasedproportion was21.0%), and that of Liaodan527was increased significantly by spraying Kangmei plantgrowth regulator at25ml666.7m-2(the increased proportion was17.9%).