Response of canola (Brassica napus L.) to exogenous application of nitrogen, salicylic acid and gibberellic acid under an arid climate

Sustainable improvement of yield under limited land resources is a challenge for future food security and types and techniques of fertilization are critical for this challenge. In this view, a 2-year study was conducted to investigate the interaction of nitrogen (N) with salicylic acid and gibberellic acid on productivity and quality of canola (Brassica napus L.) during the year 2014-15 and 2015-16. The experiment was conducted in a split-plot arrangement of treatments where four N levels (60, 80, 100, 120 kg ha^-1), kept in main plots, and four levels of plant growth regulators PGRs [Control, salicylic acid (100 ppm), gibberellic acid (100 ppm) and combination of the two], kept in sub-plots, and replicated three times. The results indicated that combined application of N and PGRs in either combination improved the morphological/yield parameters, seed yield and seed quality attributes of canola crop. The maximum seed yield of 2230 kg ha^-1 was recorded when N application @ 120 kg ha^-1 interacted with combine application of salicylic acid and gibberellic acid. The combined application of gibberellic acid and salicylic acid enhanced the seed yield and seed oil contents of canola by 13.3-17.7% and 28.9-29.8%, respectively, than control treatment (no application of salicylic acid and gibberellic acid) during the both years of experimentation. Therefore, to combat emerging food security issues, combined application of salicylic acid and gibberellic acid along with N (at 100/120 kg ha^-1) will be a practicable option to improve the productivity and quality of canola grown under arid climates.