Study On Occurrence, Disease Resistance And Chemical Control Of Fusarium Head Blight Of Wheat In Hebei Province

Fusarium head blight(FHB) is the main disease in the wheat-growing area along Yangtze river in China. Because of the weather getting warmer, the melioration of the planting and irrigation conditions, FHB occurrence area has been constantly enlarging from Yangtze river area to north in recent years. Now it is a threat to the wheat production of Hebei Province.One hundred and fifteen wheat samples were collected from 24 counties of Handan, Xingtai, Hengshui, Shijiazhuang and Baoding city of Hebei province. Paper-roll-testing method was used to detect the FHB infection on grains, and the pathogens from the infected grains were isolated. Results showed that the samples from Xinle, Pingshan, Luancheng, Nanhe, Longyao and Xingtai counties were seriously infected by FHB. Whereas those from other counties were slightly infected. Based on the isolation and identification of the pathogen, Fusarium graminearum was identified as the main pathogen of Fusarium head blight in Hebei province. The isolation frequency was as high as 91.93%.The resistance test of wheat genotypes from Hebei province and Europe to FHB was conducted in the field. Results showed that the genotypes of Hebei province had higher resistance to FHB, especially the genotypes of BAINONG 8717 and BAINONG 63, whereas the European genotypes had lower resistance. The same situation was on leaf blotch of wheat. However, the genotypes from Hebei did not show as much resistance to powdery mildew and leaf rust as European ones.Resistance of Hebei genotypes currently used or will be used to mycotoxin by means of suppression of radical growth method was tested in the laboratory. Results showed that resistance of AIFENG 11, HENONG 859, NC 2, HUAGUOSHAN 8, HENONG 822, ZHONGMAI 9, HUA 5022, LANLIAO WHEAT, LANGYA.N 7, XIAOSHAN 230, 60836 was the same level as the resistant control SUMAI 3. But the mycotoxin resistance of SHIXIN 703 was significantly better than that of SUMAI 3.Chemical control experiment was conducted in the field during the flowering stage of wheat for the controlling of FHB. Results showed that every fungicide treatment had some control efficacy to FHB and resulted in the increase of the yield. For all the treatments, the mixture of ALERT and CHARISMA (0.5+0.75) L/ha was the best for yield increase and the treatment of CARAMBA 1.2 L/ha or HORIZON 1 L/ha was the best to control FHB. However, Bumper super was the suitable one for both the controlling of FHB and the increasing of the yield. Moreover, every fungicide treatment had good control effect onwheat leaf rust.Inhibitory effects of fungicides to Fusarium graminearum were tested by means of mycelial growth inhibition method. Among 4 fungicides, carbendazime and tebuconazole had the stronger inhibitory effects with the EC50s 2.80 g/ml and 13.33 nl/ml, respectively. The best proportion of the mixture of the two fungicides was tested by using Horsfall method. Results showed that the mixture of carbendazime and tebuconazole with EC50 20:80 had synergistic effect. Greenhouse experiment showed that the control effect reached as high as 94.29% with the mixture at 1200 times of dilutions.