USE OF PLANT ANALYSIS TO PREDICT SULFUR DEFICIENCY IN RAPESEED (Brassica napus and B. campestris)

The sulfur status of rapeseed (Brassica napus and Brassica campestris) plants grown in field studies was assessed using a variety of plant indices; percent sulfur, percent hydriodic acid reducible sulfur (HI-S in plant dry matter), HI-S:total S ratio, and total N:total S ratios. Of these, HI-S:total S determined at the rosette growth stage was the most accurate and consistent index of seed yield. A growth chamber study indicated that the HI-S:total S ratio would not be affected by nitrogen fertilizer application at normal field rates. Key words: Sulfur, deficiency, rapeseed (Brassica spp.), plant analysis