Study On The Prevention And Control Of Apple Replant Disease By Allium Fistulosum Rotation After Dazomet Fumigation

The experiment was carried out at the National Apple Engineering Center Experimental Station of Shandong Agricultural University,College of Horticulture,Shandong Agricultural University and State Key Laboratory of Crop Biology in 2015 and 2017.The experiment took 27 years of apple orchard soil as the cultivation substrate and Malus hupehensis Rehd.seedlings as test materials.Under the condition of potting for two years,the Allium fistulosum rotation after dazomet fumigation was studied for soil environment and Replantation of Malus hupehensis Rehd.In May 2015,the following treatments were performed: the old apple orchard soil was rotated Allium fistulosum;the soil of the old apple orchard was fumigated with a concentration of 0.2‰ of dazomet soil in the soil weight;the Allium fistulosum rotation after dazomet fumigation;the soil was compared with the soil of an old apple orchard.In May 2016,the seedlings of Malus hupehensis Rehd.were uniformly planted and the effects of different treatments on the seedlings of Malus hupehensis Rehd.were studied for two years(2016-2017).The results show: 1?Rotation Allium fistulosum can increase the amount of bacteria in the soil,and the fumigation of dazomet significantly reduce the number of bacteria and fungi.The results of two years in August 2015 and August 2016 showed that compared with the old apple orchard soil,the number of fungi in soil treated with rotation Allium fistulosum was reduced by 15.1% and 10.2%,the number of bacteria increased by 20.0% and 21.2%,Compared with the dazomet fumigation,The number of fungi in the Allium fistulosum rotation after dazomet fumigation was reduced by 37.1% and 41.9%.The gene copy number of Fusarium proliferatum was reduced by 22.3% and 34.0%,and the number of bacteria decreased by 27.1% and 54.4%,respectively.2?The treatment of Allium fistulosum rotation after dazomet fumigation significantly changed the soil fungal community structure.The results of principal component analysis of T-RFLP(PCA)and cluster analysis showed that,the Allium fistulosum and dazomet fumigation treatment changed soil fungal community structure,and Allium fistulosum rotation after dazomet fumigation changed significantly.3?Allium fistulosum rotation could increased the soil enzyme activity.Compared with CK,the soil enzyme activity(urease,surcease,catalase,phosphatase)was increased by 23.4%,5.1%,29.8%,12.8%.Compared with dazomet fumigation those indices were improved 18.8%,15.2%,52.4%,40.0%.4?The treatment of Allium fistulosum rotation after dazomet fumigation can significantly promote the growth of replantated Malus hupehensis Rehd..in July 2016,compared with dazomet fumigation,the plant height,stem diameter,fresh weight,dry weight and root activity of M.hupehensis Rehd.seedlings with a Allium fistulosum rotation after dazomet fumigation were increased by 34.5%,19.5%,34.0%,46.5%,20.6%.those indices were improved 29.9%,28.4%,21.8%,24.8%,26.5% in July 2017.5?The treatment of Allium fistulosum rotation after dazomet fumigation can significantly promote the activity of anti-oxidative enzymes and photosynthetic efficiency in the leaves and roots of M.hupehensis Rehd..Compared with the dazomet fumigation,the respiration rate of the roots of the M.hupehensis Rehd.in July 2016 and July 2017 respectively increased by 20.6% and 26.5%,and the activity of SOD increased by 16.9%.18.2%;POD activity was increased by 21.8% and 29.9%;CAT activity was increased by 19.1% and 16.9%.