QUALITY PARAMETERS OF CANOLA AS AFFECTED BY NITROGEN AND SULFUR FERTILIZATION

Abstract

Field experiments were conducted at Cereal Crops Research Institute Pirsabak Nowshera, Pakistan, for two years (2003–2004 and 2004–2005) to evaluate the effects of nitrogen (N) and sulfur (S) levels and their methods of application on quality parameters of canola (Brassica napus L. cv. ‘Bulbul-98’). Four levels of S (0, 20, 40, and 60 kg ha⁻¹) and three levels of N (80, 120, and 160 kg ha⁻¹) and a control treatment (with both nutrients at zero level) were applied as a sole dose at sowing, in two split applications (half each at sowing and leaf rosette stages) and three split applications (one third each at sowing, leaf rosette stage, and early flowering). Large increases in oil and protein concentrations were measured at 40 kg S ha⁻¹ while no further significant increase was observed at 60 kg S ha⁻¹. However, increasing level of S consistently increased glucosinolate concentrations to the highest level of 60 kg S ha⁻¹. Nitrogen significantly increased protein concentrations up to the maximum level of 160 kg N ha⁻¹ while glucosinolate concentrations were increased up to 120 kg N ha⁻¹. However, oil concentrations showed negative trend to increasing level of N.

Keywords:

• canola
• nitrogen
• sulfur
• protein
• oil
• glucosinolate