Influence of Elicitors on Growth and Yield of Black Cumin (Nigella sativa L.) Varieties

Black cumin is a miracle herb, an emerging seed spice and a medicinal plant of great demand. Black cumin has been used since thousands of years as a spice and food preservative as well as a protective and curative remedy for several disorders. A field experiment was conducted at the Department of Plantation, Spices, Medicinal and Aromatic Crops, College of Horticulture, UHS Campus, GKVK, Bengaluru, from November 2018 to March 2019. The experiment followed a randomized complete block design (RCBD) with three replications and included two factors: varieties and elicitors. Among the various treatment combinations, foliar application of methyl jasmonate at 100 ppm resulted in the highest recorded values for plant height (46.7 cm), primary branches (5.43), stem diameter (4.62 mm), dry weight of plants (8.42 g), and plant spread (397 cm2) when applied with nitric oxide (Sodium Nitroprusside (SNP)) at 2 mM on Pant Krishna variety. Conversely, the significantly highest chlorophyll content in leaves was observed in the Azad Kalonji variety sprayed with salicylic acid at 100 ppm. Furthermore, the significantly highest numbers of capsules (22.60), seeds per capsule (84.28), and seed yield per hectare (12.40 q) were recorded in Pant Krishna sprayed with methyl jasmonate at 100 ppm. The present study concludes that all varieties, including Azad Kalonji, AN-20, and Pant Krishna, performed equally well regarding growth and yield attributes in this location. Among the elicitors tested, methyl jasmonate and salicylic acid at 100 ppm show promise for commercial cultivation of black cumin.