Effect of Biofertilizers on the Yield and Yield Components of Black Cumin (Nigella sativa L.)

Application of biological fertilizers is one of the most important methods for plant nutrition in ecological agriculture. In order to investigate the effect of biofertilizers on yield and yield components of black cumin (Nigella sativa L.), a field experiment was arranged in a randomized complete block design with three replications during 2007 growing season at the Agricultural Research Station of Ferdowsi University of Mashhad. Treatments included: (A) Azotobacter paspali, (B) Azospirillum brasilense, (C) the fungus of Glomus intraradaices, C+A, C+B, A+B, A+B+C, and control without no biofertilizers. In all treatments except control, the amounts of 15 mg of each biofertilizer were applied to 110 g of seeds. Results indicated that application of biofertilizers enhanced yield and yield components and decreased percentage of hollow capsules. Plant performance was better with application of Azospirillum plus mycorrhiza and a mixture of Azotobacter, Azospirillum and mycorrhiza in terms of yield determining criteria. The maximum and minimum amounts of seed yield were recorded in the B+C treatment with 41.4 gm-2, and control with 24.1 gm-2, respectively. There was no significant correlation between number of capsules per plant and seed yield, but the positive and significant correlation between number of branches per plant, number of seeds per capsule, 1000-seed weight and seed yield was observed. This study showed that application of suitable biofertilizers could increase yield and yield components of black cumin.