Singh, V. K.Singh, Vivek2021-07-072021-07-072020-12-21Singh Vivek 2020. STUDIES ON WILT INCIDENCE AND CULTURAL VARIABILITY OF Fusarium oxysporum f.sp. udum OF PIGEONPEA COLLECTED FROM DIFFERENT DISTRICTS OF BUNDELKHAND REGION OF U.P. M.Sc. Thesis. 33p.https://krishikosh.egranth.ac.in/handle/1/5810170180Pigeon pea Cajanus cajan (L.) is an important pulse crop grown throughout India. Fusarium udum is the most important disease of this crop. Survey was conducted of pigeonpea growing areas of 4 districts in Bundelkhand region of Uttar Pradesh during 2019-20. The average disease incidence ranged between 3.25% to 49.00% from district to districts. The average incidence percentage of wilted plants in Chitrakoot district was 39.06% followed by Banda district 25.67%, Hamirpur district 15.99% and Mahoba district 14.64% respectively. Fusarium udum was found constantly associated with the root samples. This indicates that this fungus, a well known wilt pathogen, was primarily responsible for the wilt disease of pigeonpea. Pathogenicity of Fusarium udum was tested on pigeonpea variety ‘Bahar’ all isolates of F.udum showed the typical wilting symptoms and proved Koch’s postulates. The height and number of leaves was maximum in mahoba isolates followed by hamirpur, banda and chitrakoot isolates. The maximum wilting was recorded in chitrakoot isolate followed by banda, hamirpur, and mahoba isolates. Chitrakoot isolate of F.udum was found more pathogenic and caused higher wilt incidence than other isolate. All the isolates differed in their radial growth colony characters on both solid media. It was found that PDA was the best medium in compare to PSA. The chitrakoot isolate was fast growing followed by banda, hamirpur and mahoba isolates. Sporulation was moderate to excellent in different isolates. The highest radial growth was observed in chitrakoot isolate on PDA while minimum radial growth was observed on PDA in mahoba isolate. However, the maximum radial growth was a recorded on PSA in chitrakoot isolate and minimum radial growth in mahoba isolate. Micro conidia are single or bicelled, hyaline, mostly curved, ovoid to fusoid and scattered and measure 3.80-9.12 x 0.98-2.10μm. Macro conidia which are hyaline, thin walled, falcate with a distinct foot cell, and an apical cell that decreases in width towards the tip. The most distinguishing characteristic of the macro conidia are their strongly curved or hooked apices and measure 11-21.12 x 1.95 to 3.78μm.EnglishThesis