Vol. 10, Issue 9 (2021)

Author(s):
CH Bhargavi, Sobita Simon and Abhilasha A Lal

Abstract:
Coriander (Coriandrum sativum L.)” is also known as ‘cilantro’ belongs to the family Apiaceae. The commonly found pathogen Alternaria alternata that is responsible for the disease Alternaria leaf spot in coriander. The common symptoms of Alternaria leaf spot are tiny dark coloured circular spots on foliage and stems of coriander. This shows negative effect on yield and also produces a very low quality which may notably reduce the market value of coriander due to the presence of spots and lesions on foliage. Management of this disease mainly depends on chemical methods. To reduce the use of chemical fungicides and due to the negative impact of chemical methods on environment and soil health one such attempt has been made to evaluate the effect of selected botanicals in vivo at Central Research Field and Department of Plant Pathology, SHUATS, Prayagraj and Uttar Pradesh. Selected botanicals viz., citronella essential oil, peppermint essential oil, thyme essential oil and neem oil at 0.2% concentration and mancozeb @0.2% were tested in-vivo against alternaria leaf spot of coriander during Rabi 2020- 2021 for their efficacy against the disease, plant growth & yield parameters. Among the treatments used in this study significantly lowest disease intensity (26.26%) in coriander at 30, 45 and 60 DAS, maximum percent reduction over control (46.32), highest plant height (72.26 cm), higher number of branches per plant (27.33), higher number of umbels per plant (15.00), highest yield (7.00 q ha^-1), higher gross return value (Rs. 56,264 ha^-1), net return value (Rs. 37,26 ha^-1) and B: C ratio (2.96) were recorded in treatment T₃ – citronella essential oil @0.2% followed by T₄ – peppermint essential oil @0.2%, T₂ – thyme essential oil @0.2% and T₁ – neem oil @0.2% (56.66 cm) as compared to T₅ – mancozeb @0.2%(treated check) and T₀ – control(untreated check).