Effect of sulphur and plant-growth regulators on growth, yield and economics of summer groundnut (Arachis hypogaea)

A field experiment was carried out during summer 2014 at summer Junagadh, Gujarat, to study the effect of sulphur and plant-growth regulators on growth, yield and economics of summer groundnut (Arachis hypogaea L.). Sulphur fertilization up to 40 kg S/ha significantly increased plant height, dry-matter accumulation (60 days after sowing, DAS), total chlorophyll content (55 DAS) and mature pods/plant, whereas, dry-matter accumulation at 90 DAS and at harvesting, immature pods/plant, weight of mature and immature pods/plant, and 100-kernel weight increased significantly up to 20 kg S/ha. Significantly higher number of total and effective root nodules/plant (60 DAS), and shelling outturn were recorded at 40 kg S/ha over the control. Significantly higher pod and haulm yields were realized with the application of 20 kg S/ha by 21.9 and 13.0% over the control respectively. An additional net returns of 18.3 × 10³/ha were obtained with the application of 40 kg S/ha in comparison to the control with the highest benefit: cost ratio (1.99: 1). Maximum plant height, dry-matter accumulation (60 and 90 DAS, and at harvesting), total chlorophyll content (55 DAS), number and weight of mature and immature pods/plant were recorded with the foliar spray of NAA @ 40 ppm twice at 25 and 50 DAS, whereas the maximum number of effective root nodules/plant at 60 DAS and 100-kernel weight were recorded with the application of GA₃ @ 20 ppm twice at 25 and 50 DAS. Application of NAA @ 40 ppm twice at 25 and 50 DAS significantly enhanced the pod and haulm yields by 33.8 and 18.1% over the control, respectively, and was at par with GA₃ @ 20 ppm twice at 25 and 50 DAS. In comparison to the control, the maximum additional net returns of 21.2 × 10³/ha and benefit: cost ratio (2.01: 1) were also obtained under this treatment.