Sulphur application improves the growth, seed yield and oil quality of canola

Sulphur (S) nutrition is very important for harvesting potential seed and oil yield of rapeseed. This study evaluated response of foliage applied thiourea on the performance of two canola cultivars Shiralee and Dunkeld. Sulphur was applied to soil (40 kg ha−1) or foliage (500 and 1,000 mg L−1) at rosette, bud initiation and flowering stages using elemental S or thiourea as source, respectively; no S application was taken as control. Among all the treatments, soil application of S improved the crop growth, yield and oil quality in both cultivars and was followed by foliar application of thiourea at 1,000 mg L−1 compared with no application. Soil applied S and foliar thiourea (1,000 mg L−1) delayed the flowering and maturity. Soil and foliar applied S significantly improved leaf area index, crop growth rate, net assimilation rate and chlorophyll contents. Plant height, number of branches, siliqua per plant, seed number per siliqua, 1,000-seed weight, biological and seed yield were also increased by soil applied S and foliage applied thiourea (1,000 mg L−1). Nonetheless, improvement in harvest index, seed oil, protein and glucosinolate contents was only observed from foliage applied thiourea (1,000 mg L−1). Response of cv. Shiralee to sulphur application was better than cv. Dunkeld. In conclusion, foliar applied thiourea (1,000 mg L−1) can have potential to improve growth, yield and oil quality in canola and can be economically viable and attractive alternative source.