K. APARNA DAS, RUSHIKESH KAILASH BHOSALE, SANKET SUDHAKAR CHAVAN, MEENAKSHI RANA AND SEWETA SRIVASTAVA*
Department of Plant Pathology, School of Agriculture, Lovely Professional University, Phagwara-144 411 (Punjab), India
*(e-mail : seweta.21896@lpu.co.in; Mobile : 83602 87932)
(Received : July 5, 2022; Accepted : August 10, 2022)
ABSTRACT
Tomato (Lycopersicon esculentum L.) is one of the most important economic vegetable crops cultivated in
India. Among all the fungal diseases, early blight caused by Alternaria solani (Ellis and Martin) is one of
the worlds most catastrophic diseases. The present research work was conducted with the aim to
determine the effect of three Trichoderma species and five fungicides by using dual culture assay against
Alternaria solani. Effect of different pH levels, temperature, light intensity and media were tested against the growth of A. solani under in vitro conditions. Trichoderma harzianum was very effective in managing early blight of tomato. Combination of azoxystrobin 11.4%+difenoconazole 18.2% SC was found most
effective by showing 96.60% inhibition against the pathogen under in vitro condition, followed by
propiconazole 25% EC (81.70%) and mancozeb 75% WP (74.60%), respectively. A. solani was maximum in
pH range of 6.00-6.50 and temperature range of 25-30°C. The exposure of the fungus to alternate cycles
of 12-h light and 12-h darkness resulted in the maximum mycelial growth of A. solani compared to
continuous light and dark. Among the different media tested, potato dextrose agar (PDA) medium
supported significantly the maximum growth of test pathogen followed by oat meal agar (OMA). On the
basis of present study, the fungal bioagents, might be exploited for future plant disease management
programs (DMP) to save environmental risk.
Key words : Alternaria solani, biocontrol, dual culture technique, early blight, management