Effect of fertility levels, biofertilizers and brassinosteroid on productivity, profitability and nutrient uptake of fenugreek (Trigonella foenum-graecum)

A field study was conducted during the winter (rabi) seasons of 2012–13 and 2013–14 at Ajmer, Rajasthan, to assess the response of fenugreek (Trigonella foenum-graecum L.) to fertility levels, biofertilizers and brassinosteroid. Three fertility levels [60, 80 and 100% recommended dose of fertilizers (RDF) 40 kg N + 40 kg P2O5 + 10 kg S/ha)] and 3 biofertilizer inoculations [Rhizobium, phosphate-solubilizing bacteria (PSB) and Rhizo-bium + PSB) in main-plots and 3 concentrations of brassinosteroid (BR), viz. water spray, BR 0.25 ppm and BR 0.50 ppm, in subplots were studied in split-plot design with 3 replications. Significantly the highest values of growth parameters, nodules/plant, yield attributes, seed yield (2.24 t/ha), haulm yield (5.24 t/ha), net return (56, 200), benefit: cost (B: C) ratio (1.88) and content and total uptake of N, P and S were recorded with application of RDF over lower fertility levels. Dual inoculation of seed with Rhizobium + PSB resulted higher growth, nodules/plant, yield attributes, seed yield (2, 09 t/ha), net returns (50, 690) and total uptake of nitrogen (130.94 kg/ha), phosphorus (17.17 kg/ha) and sulphur (15.82 kg/ha) over their sole application. Interaction of fertility levels and biofertilizers was also found significant in yield attributes and consequently in seed yield. Application of 100% RDF + dual inoculation, being at par with 80% RDF + dual inoculation, gave the highest seed yield (2, 287 kg/ha) and net returns (57, 940). However, the highest benefit: cost ratio (1.96) was obtained under 80% RDF + dual inoculation. Foliar spray of brassinosteroid 0.50 ppm resulted in significantly higher plant height (69.1 cm), branches/plant (5.48), yield attributes, seed yield (2.10 t/ha), net return, (50, 040), benefit: cost ratio (1.64) and total uptake of nutrients (N, P and S) over water spray and BR 0.25 ppm respectively. Thus, integration of 80% RDF with dual inoculation and supplemented with foliar spray of brassinosteroid 0.50 ppm at 50 and 70 DAS is better for realizing higher yield and economics in fenugreek.