Incidence of Fusarium udum Butler on pigeonpea cultivars at seedling stage in sterilized and unsterilized soil.

摘要

Fusarium wilt caused by F. udum Butler is one of the major diseases of pigeonpea in tropics and subtropics Disease incidence is highly influenced by soil microbial flora/fauna and cultural practices. The study on incidence of F. udum was undertaken at seedlings stage in sterilized and unsterilized soil in pots. Inoculum of F. udum was added at 6 g colonized sorghum grains per kg soil. Un-inoculated soil served as control. The observations revealed that in sterilized soil, cultivar Bahar showed significantly higher (24.58%) mortality of plants than cultivar ICP 11290 (12.53%). Similarly, in unsterilized soil, the incidence of F. udum was significantly higher (22.50%) in cultivar Bahar than cultivar ICP 11290 (19.66%), as compared to control (10.00%) and (16.67%), respectively. The plant mortality in both cultivars started 4 weeks after sowing in both type of soils, but in sterilized soil, maximum incidence was recorded at week 6 and then diminished in cultivar Bahar. While, in cultivar ICP 11290 incidence was found to be constant from weeks 5 to 7. Conversely, in unsterilized soil cultivar ICP 11290 showed sigmoid trend, while, cultivar Bahar exhibited almost reverse trend in the mortality at weeks 5, 6 and 7. This suggests that ICP 11290 is less susceptible and wilt suppression depends upon the microbiological status of the soil.