Ravichandra, N. G.PUSHPALATHA, R.2020-09-182020-09-182019-08-08Th-12337https://krishikosh.egranth.ac.in/handle/1/5810151488Root-knot nematode, Meloidogyne enterolobii was reported for the first time on guava in 2016 from Karnataka and is emerging as a major threat to commercial production of guava across India. Several fungi associated with M. enterolobii infested guava rhizosphere increased the wilting of guava plants. Investigations were carried out on isolation and identification of nematode and major pathogenic fungi associated with nematode infested guava rhizosphere, screening popular guava cultivars for their reaction to M. enterolobii and management using various treatments viz., Purpureocillium lilacinum, Pochonia chlamydosporia, Fluopyram, Fluensulfone, Bacillus velezensis, Pseudomonas fluorescens, Bacillus pumilus and Carbofuron 3G under field condition. Among the several fungi, Fusarium solani was predominant in the rhizosphere of guava infested with M. enterolobii. Among eight guava cultivars (Lalit, Allhabad Safeda, Sardar, Arka Mridula, Arka Poorna, Arka Rashmi, Arka Kiran and Arka Amulya), it was observed that Lalit and Allahabad Safeda were moderately resistant to M. enterolobii with root knot indices of 3.0 at 60 days after nematode inoculation. Under field condition, new nematicide Fluopyram 400 SC@500g a. i. ha-1 (0.23 mL L-1 plant-1) at monthly interval was effective in reducing the nematode population in soil (650/ 200 cc) , root (99.33 / 5 g) and maximum reduction of galls (13.33/ 5 g of root) and egg masses (14.00/ 5 g of root) over control ( 1033.33/ 200 cc, 260/ 5g of root, 27.33/ 5 g of root, 29.67/ 5 g of root respectively).EnglishThesis