Biocontrol potential of Gliocladium virens against damping off inducing pathogens in Amaranthus hybridus

Abstract

Damping-off disease is caused by several soil-borne fungi such as Pythium ultimum and Rhizoctonia solani, which infect seedlings and cause them to ‘damp off’ or collapse and decay. The aim of this study was to evaluate the biocontrol potential of Gliocladium virens against damping off inducing pathogens in Amaranthus hybridus. Infected leaves of Amaranthus hybridus were collected from some selected farmlands in Lapai Local Government Area of Niger State, Nigeria. The fungal species were isolated from the plants with damping-off symptoms using the agar pour plate method. The isolation of fungal species from goat dung and chicken droppings was conducted using the serial dilution agar plate method. Isolates were identified using morphological characteristics features from the mycological atlas. Pythium ultimum and Rhizoctonia solani were associated with the plants and upon testing the pathogenicity of these isolated fungi on the plants, the severity of the disease was 85 to 100%. The fungus Gliocladium virens was identified from the two composted manures. Amaranthus hybridus seeds treated with Gliocladium virens produced plants that have significantly increased plant height (45.67cm) than untreated seeds (27.10cm). Higher stem girth was observed when the seeds were treated with Gliocladium virens (8.21cm). This was significantly different from the stem girth in plants from untreated seeds (4.12cm). Number of leaves produced per plant was significantly increased in plants from treated seeds (23.54) and decrease in plants from untreated seeds (13.17). From the result of this study, it could be concluded that, Gliocladium virens when seed coated, is a potential biological agent in controlling damping-off diseases and this will help the general public towards eradicating vegetable diseases.