Abstract:
This study evaluated the efficacy of Trichoderma virens solid formulation against
Athelia rolfsii and assessed biocontrol ability, viability, plant growth promotion and
yield enhancement ability. Symptomatic cowpea plants were collected from the
faculty field, Faculty of Agriculture, Anuradhapura for pathogen isolation. Along
with pathogenicity test and dual plate assay, pot and field experiments were
conducted under controlled environment and open field conditions respectively. A.
rolfsii was applied to the crown area of seedlings (6 × 105 CFU) using agar disc
method. Trichoderma virens was applied with spore suspension at a concentration of
7 ×108 spore mL-1 at seeding and 3 ×106 spore mL-1 in 3-week intervals. The efficacy
of T. virens was tested in a pot trial with eight treatments: T1: only soil, T2: A. rolfsii
and only soil, T3: A. rolfsii and T. virens only, T4: A. rolfsii and full DOA
recommendation, T5: A. rolfsii with full DOA and T. virens, T6: A. rolfsii and half
DOA, T7: A. rolfsii, T. virens with half DOA, and T8: A. rolfsii and carbendazim.
Plant growth parameters and yield components were meticulously recorded.
Additionally, CFU and disease incidence were monitored. Data analysis was
conducted using repeated mixed effect model, three-way and four-way ANOVA
models in SAS studio version 9.0 software. The pathogen was confirmed
morphologically and molecularly as A. rolfsii. Pathogenicity was confirmed via
Koch’s postulate. T. virens demonstrated 86.02% inhibition of A. rolfsii in a dual plate
assay. The application of T. virens exhibited zero disease incidence. Treatments with
T. virens have a significant effect (p<0.05) on pod number, root length and seed
weight. Results indicated that T. virens remained viable in soil throughout the
experimental period, ensuring sustained benefits. In conclusion, T. virens
demonstrates significant potential as a biological alternative to chemical fungicides
for managing Athelia rolfsii, effectively promoting growth and suppressing disease
in cowpea plants.
