Studies On Chemical Treatments Of Watermelon And Muskmelon Seeds For Bacterial Fruit Blotch

Bacterial fruit blotch(BFB) occurred in most provinces in China.Seed borne is an important preliminary infection source of the disease. A great deal of investigation has indicated that once the fruits are infected, the disease is very difficult to control.Therefore,chemical treatment techniques of seed borne is an important mean to control the disease. But there were no ideal chemicals and treatment techniques to treat the infected seeds of watermelon and muskmelon for controlling BFB.Therefore, seed chemical treatment techniques for BFB were carried out as follows:Indoor pesticide screening tests were carried out for pathogens of watermelon and muskmelon bacterial fruit blotch by inhibitory zone method. The test results of63kinds of pesticides indoor showed that:72%agricultural streptomycin sulfate SPX (Hua Bei) and other10kinds of pesticides on strains plsbtw20from watermelon and strains plsb23from melom showed good indoor antibacterial effect and their inhibition zones on the pathogens were over than10.0mm in diameter; Sensitivities of two strains to same pesticide were different. Pesticides such as agricultural streptomycin sulfate72%SPX (Shijiazhuang Winton), agricultural penicillin50%WP (Shandong Yongxiang), cupric hydroxide53.8%WG (Huizhou in Motion) had significant inhibitory effect on strains plsbtw20, but no inhibitory effect on plsb23; At the same time, we also found there were very different effects on the pathogen that same pesticides come from different producers.Taking all factors to consider, agricultural penicillin50%WP, agricultural streptomycin72%SPX, erythromycin, enrofloxacin, new phytomycin90%SPX, mancozeb50%WP, xiJunShaXing50%WP and hydrochloric acid36%were choosed to treat seeds of watermelon and muskmelon further.The result of pesticide treatments for seeds of watermelon and muskmelon for BFB showed that although pesticides including agricultural penicillin50%WP, mancozeb50%WP, XiJunShaXing50%WP and erythromycin had good indoor inhibitions on pathogens but seedlings incidences of BFB were very high after watermelon seeds treated with these pesticides. Enrofloxacin had a excellent effect indoor and low incidence of seedlings, but there were serious injuries on seedlings which all of seedling cotyledons turn yellow and growth were inhibitoried seriously. Pesticides such as New Phytomycin90%SPX and agricultural Streptomycin72%SPX had no bad effects on germination of watermelon seeds and low seedling incidences. While seeding incidences with hydrochloric acid36%was significantly lower than that of control, but the emergence of watermelon seeds and seedling growth were inhibitoried in some extent, it should be popularized carefully.