Management of Chili Root Rot Pathogen, Rhizoctonia solani, with Potential Rhizobacteria

Abstract

Chili (Capsicum annuum L.) belongs to the solanaceae family. It is a major vegetable crop grown on a wide scale in Asia. Nearly 20% of Pakistan's total vegetable producing land is utilized for cultivating chili. Various plant pathogens including viruses, fungi, bacteria and nematodes are responsible for causing diseases in chili crop. Among fungal diseases, root rot is an important fungal disease which is caused by Rhizoctonia solani. In the present study, a survey of different localities of Multan district were conducted and plants with prominent root rot symptoms were collected and subjected to characterization. Moreover, the disease incidence and prevalence was calculated in surveyed localities. Highest disease incidence i.e. 20.77% was evident in samples collected from Tatay Pur and the lowest disease incidence (7.59%) was observed in samples of Suraj Miani. Morphological identification of root rot samples was carried out based on growth, shape, color, and hyphae structure and confirmed the association of R. solani. Koch’s postulates were confirmed after pathogenicity test which was accomplished by stem application method. About 10 rhizobacteria were isolated from rhizospheric soils of healthy plants and dual culture technique was used to manage the R. solani mycelial growth under in vitro conditions. Our results revealed that rhizobacteria 7 (RB7) exhibited the highest inhibition percentage 54.81% while the lowest inhibition percentage i.e. 40% was evident using rhizobacteria 4 (RB4) compared to control. This study helped us to provide the alternatives to the chemical fungicides that could be explored under field conditions against root rot disease as they are ecofriendly and has less impact to the human life.