Identification Of Root Rot Pathogen Of Cucuminum Cyminum L. And Inhibiting Effect Of The Mixture Of Bacillus Sp. And Pesticide On It And Their Field Trial Of Disease-control

The root rot was the most important root disease of Cucuminum cyminum L.. In recent years, this disease happened seriously and affected economy benefits of planting region. Biological control was as an active field and showed good applied future. The isolation and identification of root rot pathogen of Cucuminum cyminum L. were studied in this paper. At the same time, the control efficacy of biological bacillus and low poison pesticide mixed against root rot of Cucuminum cyminum L. was tested and the field trials of control effect were hold. The results were as follows:1. The isolation and dynamics of identification of root rot pathogen of Cucuminum cyminum L.Fusarium oxysporum, Fusarium solani (mart.) Sacc., Rhizoctonia sp. and a kind of unknown pathogen belonged to Deuteromycotina were isolated and identified. After the wound inoculation, the incidence of root rot diseases of a kind of unknown pathogen which belonged to Deuteromycotina showed a higher value of 70%, F. oxysporum, F. solani and Rhizoctonia were 50.9%, 43.2%and 11%, respectively. The incidence of root rot diseases of its mixture inoculation was 100%. The test of isolation and identification of the pathogen and pathogenecity showed that the root rot of Cucuminum cyminum L. was caused by a complex infection of F. oxysporum, F. solani, Rhizoctonia and a kind of unknown pathogen belonged to Deuteromycotina.2. The control effect of Bacillus subtilis B1, B2 and Baclillus sp.B6, B8 mixture up a low poison pesticide on root rot pathogen of Cucuminum cyminum L. and several pathogens.Using growth rate, the pesticides and its concentrations were chosen from six pesticides, which had good inhibitive effect to pathogens and had no effect on the growth of Bacillus subtilis B1, B2 and Baclillus sp.B6, B8. They were iprodione, mancozeb and thiophanate-methyl. The control effect of the mixture in the given concentration range on several pathogens was tested. The results were as follow:(1) The control effect of Bacillus subtilis B1, B2 and Baclillus sp.B6, B8 mixed low poison iprodione on the unkown pathogen were different. Compared with using single iprodione the inhibitory rate of iprodione of 0.4μl/ml and 0.8μl/ml improved 23~35 percentage points. Compared to single biological bacillus, its inhibitory rate increased 2 ~ 13 and 25 ~ 31 percentage points. The cooperation of biological bacillus and iprodione had good inhibitive...