Comparative in vitro Evaluation of Systemic Fungicides and Bioagents against Pigeonpea Wilt Caused by Fusarium oxysporum f. sp. udum
S. N. Shaikh *
Department of Plant Pathology, College of Agriculture, Latur (VNMKV, Parbhani), Maharashtra, India.
R. A. Chavan
Department of Plant Pathology, College of Agriculture, Ambajogai, (VNMKV, Parbhani), Maharashtra, India.
Sunita J. Magar
Department of Plant Pathology, College of Agriculture, Latur (VNMKV, Parbhani), Maharashtra, India.
V. S. Hande
Department of Plant Pathology, College of Agriculture, Latur (VNMKV, Parbhani), Maharashtra, India.
K. B. Dharbale
Department of Plant Pathology, College of Agriculture, Latur (VNMKV, Parbhani), Maharashtra, India.
V.B. Gitte
Department of Plant Pathology, College of Agriculture, Latur (VNMKV, Parbhani), Maharashtra, India.
D.E Pathak
Department of Plant Pathology, College of Agriculture, Latur (VNMKV, Parbhani), Maharashtra, India.
*Author to whom correspondence should be addressed.
Abstract
Aims: To evaluate the in vitro fungitoxic potential of seven systemic fungicides at concentrations of 500 and 1000 ppm and seven fungal biological control agents against Fusarium oxysporum f. sp. udum, the causal pathogen of pigeonpea wilt.
Study Design: Completely Randomized Design (CRD).
Place and Duration of Study: Department of Plant Pathology, College of Agriculture, Latur, Maharashtra, India. The study was conducted during 2025–2026.
Methodology: The wilt pathogen (F. oxysporum f. sp. udum) was isolated from infected pigeonpea root tissues displaying characteristic vascular discolouration. Seven systemic fungicides (Carbendazim 50% WP, Myclobutanil 10% WP, Propiconazole 25% EC, Thiophanate methyl 70% WP, Difenoconazole 25% EC, Tebuconazole 25.9% EC, and Hexaconazole 5% EC) were screened at concentrations of 500 and 1000 ppm using the Poisoned Food Technique. Seven fungal bioagents (T. harzianum, T. virens, T. hamatum, T. asperellum, Penicillium chrysogenum, Aspergillus niger, and Aspergillus flavus) were evaluated using the dual-culture technique on Potato Dextrose Agar (PDA).
Results: All tested systemic fungicides significantly inhibited pathogen mycelial growth compared with the control (P = .01). Carbendazim 50% WP produced complete growth inhibition (100.00%) at both 500 ppm and 1000 ppm. Among the remaining fungicides, Tebuconazole 25.9% EC exhibited mean inhibition of 85.18%, followed by Propiconazole 25% EC (82.78%), Thiophanate methyl 70% WP (80.14%) and Hexaconazole 5% EC (71.77%). Among the bioagents, T. harzianum achieved the maximum growth inhibition (82.04%), closely followed by T. virens (80.55%) and T. asperellum (74.82%), whereas Aspergillus flavus recorded the lowest inhibition (63.71%).
Conclusion: Among the chemical treatments, Carbendazim 50% WP, and among the biocontrol agents, T. harzianum, exhibited high efficacy in vitro, highlighting their potential for incorporation into integrated disease management strategies against pigeonpea wilt.
Keywords: Pigeonpea, vascular wilt, Fusarium oxysporum f. sp. udum, systemic fungicides, carbendazim, tebuconazole, propiconazole, Trichoderma harzianum, poisoned food technique, dual-culture technique