Efficacy of aqueous and cow-urine based biopesticides against Phytophthora nicotianae var. parasitica causing buckeye rot of tomato

Abstract

Buckeye rot of tomato, caused by Phytophthora nicotianae var. parasitica, is a serious threat to the crop production and has taken a heavy toll of the crop in India which affects mostly the fruits during both spring and winter season crops. In the present investigation, aqueous and cow-urine based leaf extracts of five plants viz., Lantana camara, Artemisia vulgaris, Murraya koenigii, Eucalyptus tereticornis and Melia azaderach were evaluated for their efficacy against the test pathogen under in vitro conditions. Out of five aqueous biopesticides, Eucalyptus tereticornis was found most effective with 51.48 per cent inhibition in mycelial growth of the pathogen followed by Artemisia vulgaris (48.52%), Lantana camara (44.81%) and Murraya koenigii (42.96%). Aqueous extract of Melia azedarach was least effective with 39.62 per cent mycelial growth inhibition. Among five cow-urine based biopesticides, Eucalyptus tereticornis was found most effective with 71.89 per cent inhibition in mycelial growth of the pathogen followed by Artemisia vulgaris (68.74%), Lantana camara (63.58%) and Murraya koenigii (59.51%). Cow-urine based botanical extract of Melia azedarach was least effective with 55.41 per cent mycelial growth inhibition.