Analysis Of Tebuconazole's Effect On Maize Emergence Under Chilling Stress

Maize is a warm-season crop.Chilling stress can inhibit the germination of maize seeds,delay the emergence and the growth of seedlings.Consequently,chilling stress can lead to low temperature injury to maize.In order to clarify the mechanism and figure out the resolutions,we analyzed the main factors resulting in low temperature injury to Maize by steriling soil and isolating soil pathogens.Further studies were conducted to determine the infectivity of pathogens and screen suitable fungicides to protect maize from low temperature injury by seed coating method.The results are shown below:Under the experimental conditions,soil pathogens,temperature and coating dosage were the main factors affecting the rate of maize emergence and maize varieties and triazole fungicides had little effect on the rate of maize emergence.Further study showed that if the soil was sterilized,the emergence of maize seeds can be significantly increased up to 95%,and the plant height increased by 52.1%~66.0%,and the seedling fresh weight increased by 129%~178%,and the root weight increased by 103.8%~193.3%.Physiological and biochemical indexes studies also showed that if soil was sterilized,tebuconazole coating benefited their resistance to the low temperature stress.Therefore,soil microorganism is the primary reason of low temperature injury.Pythium ultimum,Fusarium commune and Fusarium equiseti have strong inhibition and infectious activity on the maize root at 10?~25?.Treatments of Fusarium commune and Fusarium equiseti have a slowly growth rate,and they have no significant effect on the germination rate of Maize and no infection of shoot.But stronger inhibitory effect on maize root,shoot and lateral root growth were observed with rising temperature.Pythium ultimum is the primary pathogen causing maize low germination rate and shoot rot.Therefore,the synergistic action of Pythium ultimum,Fusarium commune and Fusarium equiseti contributed to the low temperature injury to maize.Seed treatment of cyazofamid,propamocarb and metalaxyl-M can significantly improve the emergence rate of maize,benefit the growth of Maize Seedlings.Therefore,seed treatment of fungicides can improve the low temperature resistance of maize.In summary,soil pathogens played most important role in low temperature injury to maize.Pythium ultimum is the predominant pathogen.It acts synergistically with other pathogens.seed treatment of fungicides can kill soil pathogens and increase the emergence rate of maize and improve the low temperature resistance of maize.