Study On The Pathogen Of Faba Bean Fusarium Wilt And Their Control In Changshu Of Jiangsu Province

In Changshu of Jiangsu recent years, Fusarium wilt harmed faba bean greatly,generally 10-30% faba bean were aggressed,the most was 40%. In order to protect faba bean from Fusarium wilt well, this research first studied the main species' pathogen of faba bean Fusarium wilt in Changshu of Jiangsu.The second screened the best fungicide against Fusarium in vitro,and composited this fungicide with B.subtilis B-916 in a good proportion.The control effect of the compound fungicide in field was studied in Nanjing and Changshu.Anothermore,the regulation to B-916 by tebuconazole on plate and in different soil was known to some extend. All the results were as following:(1) 100 wilt broad bean samples were obtained from Changshu of Jiangsu province in 2000 and 2001,and 94 Fusarium monoconidial strains were isolated.The author identified them and studied their virulence to faba bean,and found Fusarium oxysporum, F.avenaceum, F.moniliforme and F.equiseti were the main pathogen of broad bean Fusarium wilt, Fusarium oxysporum , F.equiseti., F.avenaceum and F.moniliforme had virulence from strong to weak in proper order.The anthor researched the Fusariums' sporulation and their virulence,and no striking correlation was found.The anthor inoculated faba bean with cotton wilt pathogens and inoculated cotton with faba bean Fusarium,and knew cotton wilt pathogen could aggress faba bean, and faba bean Fusarium pathogen did harm to cotton.(2)In the second part, 10 fungicides were used to inhibite Fusarium,and tebuconazole and prochlora against Fusarium spp.f.sp.fabae in vitro better than the others;more study were done, tebuconazole was choosen to composite with Bacillus subtilis B-916.The best compound fungicide,named TB,have the equal volum of 10000 ug/ml tebuconazole solution and of B-916 culture Iiquid(2xl010cfu/ml).(3) The effect was 42.91-57.76%,average 52.21% produced by TB seed treatment on faba bean Fusarium wilt in seedling stage,and that was 29.66-65.48%,average 46.61% inNanjing and 25.57-57.39%,average 44.67% in Changshu by TB seed and root treatment on the disease in the grown stage,a little worse than in seedling.TB treatment made product more 18.64-45.10% than control.Different root treatments didn't make great difference.Although tebuconazole of TB was reduced halfly, its effect and product was similar to that by tebuconazole singlely.The effect of B-916 was not good.If TB was used too much,it did harm to emergence,20-40gTB per 10kg seed was a good choice on this reseach.(4)In order to know some mechanism of tebuconazole and B-916 used together,the regulation to B.subtilis by tebuconazole on plate and in different soil were researched. On plate,0-lug/ml tebuconazole helped B.subtilis B-916 mutiply.Tebuconazole helped B.subtilis B-916 colonize and survive around faba bean roots in all three soil.The best was in natural soil,the second in natural soil inoculated with Fusarium spp.,and the last one in sterilized soil.The results in this reseach helped comprehensive protection against faba bean Fusarium wilt. It gave theoretical base for fungicide and technique against this disease.