Research On The Technology Of Controlling Continuous Cropping Obstacles Of Chrysanthemum

Chrysanthemum (Chrysanthemum morifolium (Ramat.) Kitamura) originated in China, and it is one of the most important ornamental plants with its rich color and inflorescence types, occupying an extremely major market share of cut flowers and flowering pot plants in the world and some of them have high medicinal value. With chrysanthemum production promotion and accumulation of planting years, the fusarium wilt causes a large area of chrysanthemum incidence of death and serious sever in qualityof chrysanthemumunder continuous cropping systems, the continuous cropping obstacles had became the most significant problems. Here,3 kinds of chrysanthemum(Chrysanthemum morifolium ’Youxiang’,Chrysanthemummorifolium’Jinba’andChrysanthemum morifolium Tzvel. cv. Chuju)with seriouscontinuous cropping obstacles had been selected to doing field experimentapplied with carbendazim, dazomet and bio-organic fertilizer under actual production conditions. The disease incidence,control rate,root activity, soil enzymes activity had been measured in order to analyze the effects. The total DNA from rhizosphere soil had been extracted for RT-PCR and PCR-DGGE, in order to analyze the soil microflora. The main results and conclusion were listed as follow:(1) The effects of bio-organic fertilizer(BOF), fungicide(carbendazim MBC) and BOF combined with MBC application on quality and soil enzymatic activities of Chrysanthemum morifolium ’Youxiang’ in continuous cropping systems were investigated. The results showed that bio-organic fertilizer and fungicide application could effectively prevent the occurrence of fusarium wilt disease of cut chrysanthemum, Thecontrol rate of MBC, MBC+BOF and BOF was 100%,100% and 92.0%; bio-organic fertilizer application was more effect on root activity, the root activity of treatmentBOF and MBC+BOFhad increased 78.1%,70.2%compared with CK;bio-organic fertilizer application wasalso effect on soil enzymes activity and quality(shoot height, stem diameter, leaf SPAD value, ray floret number, shoot fresh weight) improvement of cut chrysanthemum, while fungicide application was responsible for soil enzymatic activity suppression,but weaker than the activation of bio-organic fertilizer on them. Treatment MBC+BOF show the best quality improvement among three treatments.(2)The effects of bio-organic fertilizer(BOF), fungicide(carbendazim MBC),fumigant (dazometDAZ)and BOF combined with MBC and DAZ application on quality, soil enzymatic activities and soil microflora of Chrysanthemum morifolium’Jinba’in continuous cropping systems were nvestigated.The results showed that:carbendazim,dazomet and bio-organic fertilizer could effectively prevent the occurrence of fusarium wilt disease of cut chrysanthemum, thecontrol rate of MBC, DAZ, MBC+BOF, DAZ+BOF, BOF was 93.75%,83.86%,80.82%,84.31%,52.51%; bio-organic fertilizerappli cation was more effect on chrysanthemum quality,treatment DAZ+BOFshow the best quality improvement among five treatments;3 kinds of rhizosphere soil enzymatic activity had been increased by using bio-organic fertilizer,dazomet and carbendazim were responsible for urease activitysuppression and sucrase activity activation;5 treatments could increase the B/F value,MBC, DAZ, MBC+BOF, DAZ+BOF and BOF had increased 33.01%,80.58%,196.12%,92.23%,109.71% compared with CK by RT-PCR; all treatments could suppress the diversity,abundance and richness of rhizosphere soil fungi,bio-organic fertilizer could increase the diversity,abundance and richness of rhizosphere soilbacteria by PCR-DGGE;3treatmentswhich applied with bio-organic fertilizer(MBC+BOF, DAZ+BOF and BOF) had bright bands identified as Bacillus subtilis, showed its could survive inrhizosphere soil and take advantage of niche.(3) The BOF was applied both in nursery and transplanting of Chrysanthemum morifolium Tzvel. cv. Chuju in continuous cropping systems, the root activity, total flavonoids, yield and main physiological indicators of chrysanthemum had been measured in order to investigate the effects of controlling continuous obstacles.The results showed that:BOF could significantly increase the total flavonoids andyield, the main physiological indicators such as shoot height, stem diameter, crown diameter, root/shoot ratio and shootfresh wt. also had been increased.Treatment BOF+BOFshow the best improvement among three treatments, the yield,total flavonoids,leaf SPAD value and nitrogen contents had increased 34.71%,95.71%,73.76%,97.22%compared withCKn+CKf.