Effect of spacing and fertilizer management on seed production of sunnhemp (Crotalaria juncea)

A field experiment was conducted during the rainy (kharif) season of 2013 to 2015 on medium black soils of Rahuri, Maharashtra, to find out suitable spacing and fertilizer level for growth and seed yield of sunnhemp (Crotalaria juncea L). Treatments consisted of 2 spacings, viz. S₁, 30 cm × 10 cm and S₂, 45 cm × 10 cm, in main plots and 5 fertilizer doses, viz. T₁, control; T₂, N: P₂O₅: K₂O, 20: 40: 20 kg/ha + FYM 5 t/ha; T₃, N: P₂O₅: K₂O, 20: 40: 40 kg/ha + FYM-5 t/ha; T₄, N: P₂O₅: K₂O, 20: 60: 40 kg/ha + FYM 5 t/ha; and T₅, N: P₂O₅: K₂O 20: 60: 60 kg/ha + FYM 5 t/ha in sub-plot treatments in split-plot design, replicated thrice. The gross and net plot sizes were 5.0 m × 4.0 m and 4.40 m × 3.60 m respectively. The results indicated that, the crop sown at spacing of 30 cm × 10 cm recorded significantly higher seed yield (1.76, 2.16, 1.79 and 1.90 t/ha) than 45 cm × 10 cm (1.30, 2.06, 1.58 and 1.65 t/ha) in the kharif 2013, 2014, 2015 and pooled mean. Similarly, it also registered more net returns ( 38.2 × 10³/ha) and benefit: cost ratio (2.01) than spacing at 45 cm × 10 cm during pooled mean of 3 years. Sunnhemp crop recorded significantly higher seed yield (1.67, 2.28, 1.78 and 1.91 t/ha) with the application of fertilizer dose of 20: 60: 40 kg/ha, N: P₂O₅: K₂O+ FYM 5 t/hathan the control treatment, but it was at par with rest of all treatments during 3 years and pooled mean. Similar results were recorded for growth and yield attributes. This treatment also recorded significantly maximum net monetary returns ( 37.9 × 10³/ha) and benefit: cost ratio (1.98) than rest of all treatments in pooled mean.