Abstract

Three bioagents viz., Trichoderma harzianum Rifai, Trichoderma viride Pers. andTrichoderma virens (Miller et al) von Arx and five plant extracts viz., Artimesia absinthiumL., Datura stramonium L., Urtica dioica L., Juglans regia L. and Mentha arvensis L. were evaluated in vitro against Alternaria solani (Ellis and Martin) Jones and Grout causing early blight of potato through dual culture and poisoned food technique, respectively. Among bioagents, significantly higher mycelial growth inhibition of A. solani was recorded in the case of T. harzianum (71.85%), which was followed by T. viride (65.93%) and T. virens(58.65%) proved least effective in inhibiting the mycelial growth of A. solani. Among plant extracts, D. stramonium proved superior to all other botanicals, exhibiting (61.12%) mycelial growth inhibition of A. solani. This was followed by A. absinthium (58.54%).Urtica dioica (37.34%) proved least effective in inhibiting the mycelial growth of the test fungus.

Key words: Bioagents, plant extracts, potato, Alternaria solani, dual culture, early blight.