Assessment of Bioagents, Fungicides, Botanicals and Cow By-products for the Management of Rhizoctonia solani under In-vitro Conditions

Abstract

Fenugreek (Trigonella foenum-graecum L.) is an important forage legume and spice crop affected by root rot caused by Rhizoctonia solani. The present study was conducted under in vitro conditions in a completely randomised design at the Department of Plant Pathology, SKRAU, Bikaner, during 2021–22 to identify the pathogen and evaluate selected management options. Pathogenicity was confirmed through Koch’s postulates, and the isolate was identified by the Indian Type Culture Collection as ITCC 4838. Four bioagents were evaluated. The lowest mycelial growth was recorded with Trichoderma harzianum (23.33 mm; 74.07% inhibition), followed by T. viride (31.66 mm), Pseudomonas fluorescens (54.00 mm) and Bacillus subtilis (62.33 mm), compared with 90.00 mm in the control. Eleven fungicides were tested at 100, 200, 300 and 500 ppm. Tebuconazole 50% + trifloxystrobin 25% WG, tebuconazole 2 DS and propiconazole 25% EC produced the lowest mycelial growth, while chlorothalonil 75% WP showed the highest growth among the fungicide treatments. Seven plant extracts and three cow by-products were evaluated at 5, 10, 15 and 20%. At 20%, panchgavya and Allium sativum recorded 98.88% and 98.52% inhibition, respectively, whereas Allium cepa showed the lowest inhibition (33.33%). These in vitro results identify comparatively effective treatments for further evaluation under field-relevant conditions.