Exploration The Pathogenic Factors Of Melon Root Rot And Development Of Trichoderma Fertilizer

Melon root rot has become one of the main root diseases for melon and greatly serious in recent years.The pathogens of melon root rot in Tangshan were isolated and identified based on their morphological and molecular biological identification.And then according to the pathogenic conditions of melon root rot pathogens,Trichoderma fertilizer was developed to control melon root rot,and control effect in the pot.The main results were as follows:1.The melon root rot pathogens were isolated and identified in Tangshan Three kinds of pathogenic strain of melon root rot were isolated from typical diseased plants collected from melongreenhouse in Tangshan City Hebei Province.After morphological and molecular biological identification,the pathogenic strains were identified as Fusarium semitectum,Fusarium verticillioides and Fusarium solani.F.verticillioides was the dominant pathogen of melon root rot in Tangshan City.2.Study on the influencing factors of melon root rot pathogen growth characters By measuring the colony diameter and spore production of pathogens under different culture conditions,the optimal growth conditions of three kinds of melon root rot pathogens were summarized as follows:The optimum growth temperature of F.semitectum is 25?to 30?,humidity is 50%,pH value of 5,the optimal carbon sources for simple sugars.The optimum growth temperature of F.verticillioides is 20?to 25?,humidity is 70%-80%,pH value of 6,the optimal carbon sources for simple sugars.The optimum growth temperature of F.solani is20?to 25?,60%humidity,5 pH,the optimal carbon sources for simple sugars.The EC₅₀ values of the four fungicides against the pathogen were all as follows:seminal metronidazole roxidization>azoxystrobin>nail cream oxamphenicol>oxamphenicol.3.Determining the fertilizer fermentation conditions of Trichoderma and measuring the control efficiency on melon root rot The fermentation conditions of Trichoderma fertilizer were as follows:at 28°C,pH value under natural condition,the water content of Trichoderma solid culture substrate is 50%,the initial inoculum size is 12%,add of 3 g/L ammonium nitrate.And the fermentation culture is carried out for 6 days.When the application rate of Trichoderma fertilizer was 50 g in the field,the control effect on melon root rot was 94.12%,and the effect on melon plant growth promotion was the most obvious;in the seven treatments seted up for the control effect of Trichoderma fertilizer on melon root rot disease,the emergence rate of the treatment group without Trichoderma fertilizer CK?pathogen inoculation control?was only 32%,demonstrated that Trichoderma fertilizer could promote melon emergence and growth;in the three groups of treatments only applied Trichoderma fertilizer without pathogen inoculation,the plants were not affected,indicating that the pathogen could infect at the seed to seedling stage of melon and affect plant growth.