Vol. 10, Issue 10 (2021)

Author(s):
N Hinduja, Sobita Simon and Abhilasha A Lal

Abstract:
Onion (Allium cepa L.) which is also called as “bulb onion”, “Queen of kitchen” or “Princess of vegetables”, is one of the important cultivated crops belonging to the genus Allium and family Amaryllidaceae. Purple blotch of onion which is caused by Alternaria porri is major disease in the onion. The silkworm excreta, Trichoderma viride, Pseudomonas fluorescens and neem oil were tested under field conditions during Rabi 2020- 2021 for their efficacy against the disease and growth & yield parameters. A survey was conducted during Rabi 2020 to know the severity of purple blotch of onion in farmer’s fields in Anantapur district of Andhra Pradesh. Eight villages were selected in the district and in each village five fields were surveyed. The disease severity ranged from 23.22 to 48.39 per cent irrespective of location surveyed. The disease severity was least in Sanipalli village (23.22%) during December 2020 and highest in Venkatapuram village (48.39%) during the month of December 2020. Among the treatments the plant height (cm) at 90 DAT significantly increased in T₄ – Trichoderma viride+ Pseudomonas fluorescens+ silkworm excreta (38.0 cm) followed by T₁ – Pseudomonas fluorescens+ silkworm excreta (28.6 cm). The weight of bulb significantly increased in T₄ – Trichoderma viride+ Pseudomonas fluorescens+ silkworm excreta (53.6 gm) followed by T₃ – neem oil (46.3 gm). The bulb diameter (3.6) and yield (15.3 q/acre) significantly increased in T₄ – Trichoderma viride+ Pseudomonas fluorescens+ silkworm excreta followed by T₂ – Trichoderma viride+ silkworm excreta. Disease intensity (%) at 90 DAT (27.8%) significantly decreased in T₄ – Trichoderma viride+ Pseudomonas fluorescens+ silkworm excreta followed by T₂ – Trichoderma viride+ silkworm excreta. Higher gross return value (Rs. 27,134.1/acre), net return value (Rs. 14,334/acre), and B:C Ratio (2.11) was found in the treatment T₄ – Trichoderma viride+ Pseudomonas fluorescens+ silkworm excreta as compared to untreated check control T₀ – (1.20).