The Efficient Fungicides Screening Of Controlling Chinese Jujube (Zizyphus Jujuba Mill.) Tiepi Disease

Recently, jujube Tiepi disease becomes more and more serious in many jujube-planting areas. In our research, the symptoms characteristics on the diseased fruits were described, lots of diseased tissues were isolated and the fungicides for controlling the disease were selected in the lab. And then the fungicides which were chosen from the lab had be tested in orchard.Disease symptoms: At the beginning stage of the disease, there was one or two yellow spots which were not regular on the shoulder or the middle part of the fruits, then the area of the sports grown larger and large, the color of spots become brown and dark brown. At the same time the spots sink slightly. Later, the spots become more and more wrinkled until wizened. The sarcocarp diseased look like sponge and taste bitter greatly.Using growth rate method, twenty-three Chinese herb were tested for their toxicity to three pathogens of the jujube Tiepi disease in lab. The result showed that Rhus Chinensis and Agastache rugosus gave a strong inhibition to Alternaria alternate (Fr.) Keissler and Fusicoccum sp with the rate of inhibition more than 90%. Seven ones were chosen which have good restraining effect to Phoma destructiva Plowr. They were Stemona sessilifolia, Coryclalis yanhusuo, Coptischinensis, Cinnamomum, Agastache rugosus, Rhus Chinensis and Polygonatum sibiricum and all of them were good with rate of inhibition more than 90% too. In addition, Stemona sessilifolia, Coryclalis yanhusuo, and Coptischinensis were the most effective Chinese herb which one could inhibit mycelia growth completely.Eight fungicides were tested for their toxicity with growth method and inhibition zone method. The main results showed as following.With growth method 80%dithaneWP and 25% difenoconazoleEC were chosen with good controlling effect and lower cost to Alternaria alternate (Fr.) Keissler.. Two fungicides that 50% carbendazimWP, and 80% dithaneWp were chosen with strong inhibition and lower cost to Phoma destructiva Plowr. At the same time that 25%difenoconazoleEC, 80% dithaneWP and 50% carbendazimWP were chosen with higher inhibitive rates and lower cost to Fusicoccum sp.With inhibition zone method the same fungicides were chosen to control mycelial growth of Alternaria alternat (Fr.) Keissler. 70%MancozebWP, 10%difenoconazole WG and 25%difenoconazoleEC were significant to restrain the growth of Phoma destructive Plowr when 70%MancozebWP, 50%carbendazimWP and 10% difenoconazoleWG were chosen for good controlling effect to Fusicoccum sp. with this method too.According to the result of experiment in lab, that 25% difenoconazoleEC, 80% dithaneWP, 50% carbendazimWP and the compound of 80% dithaneWP and 50% carbendazimWP were chosen for controlling the disease in field. The results showed that the compound of 80% dithane and 50% carbendazim had best control efficacy to jujube Tiepi disease in field.