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There is usually a positive yield response when sulfur (S) is applied to rapeseed (Brassica rapa L.) plants grown on S-deficient soils. Recommendations include application of some of or the entire amount of S at planting, but the plant requirement as well as availability of S to rapeseed during its various phenological stages is not well documented. In a field trial, 40 kg S ha−1 was applied as gypsum (CaSO4·2H2O) at planting (T1), during vegetative (T2, 30 days after sowing), flowering (T3, 50 days after sowing), and pod-filling (T4, 65 days after sowing) stages, and in split doses (T5). Biomass accumulation, leaf-area index, and leaf photosynthetic rate were studied at various growth stages. Seed S (sulfate and organic S) and yield parameters were studied at harvest. Sulfur (40 kg S ha− 1) applied in three split doses during different growth stages caused maximum increase in these parameters, followed by T2 and T1. However, no significant discernable difference was observed for the application ...

Salinity is an important abiotic factor that adversely affects major agricultural soils of the world and hence limits crop productivity. An optimum mineral-nutrient status of plants plays critical role in determining plant tolerance to various stresses. A pot experiment was conducted on mustard (Brassica campestris L.) to study the protective role of added potassium (K, 40 mg kg-1 soil) against salinity-stress (0, 40 and 80 mM NaCl)-induced changes in plant growth, photosynthetic traits, ion accumulation, oxidative stress, enzymatic antioxidants and non-enzymatic antioxidants at 30 days after sowing. Increasing NaCl levels decreased the growth, photosynthetic traits and the leaf ascorbate and glutathione content but increased the leaf ion accumulation and oxidative stress, and the activity of antioxidant enzymes. In contrast, K-nutrition improved plant growth, photosynthetic traits, activity of antioxidant enzymes and the ascorbate and glutathione content, and reduced ion accumulation and oxidative stress traits in the leaves, more appreciably at 40 mM than at 80 mM NaCl. The study illustrates the physiological and biochemical basis of K-nutrition-induced NaCl tolerance in mustard as a means to achieving increased crop productivity in a sustainable way. Authors are grateful to Hamdard National Foundation (HNF), New Delhi, India for financial assistance for the work. Authors sincerely thank to Dr. Ali Qadar of Central Soil Salinity Research Institute (CSSRI), ICAR, Karnal, Haryana (India) for his valuable critical comments on the second version of this manuscript, and colleagues and staffs at Department of Botany, Hamdard University, New Delhi, for their kind support and encouragements. published