Cumulative Effect of Soil and Foliar Application of Nitrogen, Phosphorus, and Sulfur on Growth, Physico-Biochemical Parameters, Yield Attributes, and Fatty Acid Composition in Oil of Erucic Acid-Free Rapeseed-Mustard Genotypes

ABSTRACT

The feasibility of split (soil + foliar) applications of nitrogen (N) and phosphorus (P) and addition of a small quantity of sulfur (S) in the spray was tested for improving performance of rapeseed-mustard genotypes in a factorial randomized field experiment. Three genotypes (two erucic acid free, viz. Brassica napus L. cv. ‘Hyola PAC – 401’ and Brassica juncea L. Czern. and Coss. cv. ‘TERI (0E) M 21-Swarna’, and one best performing high yielding Brassica juncea L. cv. ‘Rohini’ as a check) were grown with four soil (B) plus foliar (F) applications of N, P, and S with uniform basal 30 kg potassium (K) ha^{− 1} (K₃₀), viz. (i) the optimum soil-applied treatment supplemented with the spray of deionized water (B_N90P30 + Fw) comprising control, (ii) B_N70P30 + F _N20, (iii) B_N70P28 + F_N20P2, and (iv) B_N70P28 + F_N20P2S2. Soil Plus foliar application of nutrients, particularly B_N70P28 + F_N20P2S2, improved their performance with respect to growth characteristics (shoot length plant^{− 1}, leaf number plant^{− 1}, area leaf^{− 1}, leaf area index, fresh weight plant^{− 1}, and dry weight plant^{− 1}), physico-biochemical parameters (net photosynthetic rate, stomatal conductance, carboxylation efficiency, water use efficiency, carbonic anhydrase activity, leaf NPK content, and N use efficiency), yield attributes (pod number plant^{− 1}, seed number pod^{− 1}, 1000-seed weight, seed yield ha^{− 1}, oil content, and oil yield ha^{− 1}), and fatty acid composition in oil of these genotypes. The cultivar ‘Hyola PAC-401’ performed best particularly with B_N70P28 + F_N20P2S2. The improvement in the response of genotypes to the split application of nutrients may be attributed to their ready availability through foliar application.

Keywords:

• Rapeseed-mustard genotypes
• foliar application of nutrients
• photosynthetic characteristics
• leaf NPK content
• growth and yield performance
• fatty acid composition

ACKNOWLEDGMENTS

We appreciate the research facilities provided by the Aligarh Muslim University, Aligarh (India) and the seeds supplied by the National Research Centre on Rapeseed-Mustard, Bharatpur (India).