Productivity and response of quality brassicas (Brassica sp.) – cowpea (Vigna unguiculata) sequence under different sources of nutrients and sulphur levels

Information on comparative response of quality and traditional rapeseed-mustard genotypes to inorganic and organic source of nutrients are meager. Besides, organic mustard oil is becoming popular in the market. Hence, present experiment was conducted in a fixed plot field at New Delhi between 2005–2007. Two genotypes of Indian mustard {Brassica juncea (L.) Czernj & Cosson} viz., ‘Pusa Mahak’ {high erucic acid (EA) and glucosinolate content (GC)}, and ‘Pusa Karishma’ low in EA and high GC and one genotype of summer rape (Brassica napus L.) viz., ‘GSC 3A’ (low in EA and GC) were evaluated under organic and inorganic sources of nutrients and sulphur

(S) levels and residual effect of treatments were examined on succeeding cowpea [Vigna unguiculata (L.) Walp.] for green pods. ‘Pusa Mahak’ recorded greater number of siliquae/plant and test weight, while number of seeds/siliqua were found maximum in ‘GSC-3A’ ‘Pusa Mahak’ (2.08 t/ha) and ‘Pusa Karishma’ (1.91 t/ha) being on par produced significantly higher seed yield than ‘GSC-3A’ (1.45 t/ha). In first year, seed yield (2.13 t/ha) recorded was maximum owing to integrated use of nutrients, while in the second crop cycle, integrated and organic source of nutrients, recorded similar seed yield (2.30 and 2.23 t/ha), but both the treatments were markedly superior when compared with fertilizers. Application of sulphur @ 40 kg/ha produced 19.3% higher seed yield than control. Residual effect of integrated nutrient management (INM) and organic nutrition on green pod yield of cowpea was found significant over fertilizers. System productivity as mustard seed equivalent was recorded maximum with ‘Pusa Mahak’-cowpea system, INM in the first crop cycle and organic use in the second crop cycle and 40 kg S/ha. Significant interaction was recorded between the genotypes and S levels. S uptake in seed and unit response to S application (kg seed/kg S) was highest in ‘Pusa Mahak’ (10.4).