Boron and other micronutrients

When well-designed research studies are done for micronutrients in canola, results show little if any economic benefit. The Canola Council of Canada ran boron trials in 2013-15 and found no consistent yield benefit from boron treatment, including in those plots with very high yield results.

When heatwaves and flowering coincide, boron is often touted as a remedy but research results do not support the practice. When now-retired Alberta Agriculture oilseed specialist Murray Hartman did a meta-analysis of boron studies, his results showed no relationship between boron response and temperature — even when temperatures were hot at flowering. The Canola Encyclopedia has more detail on boron.

What about other micros? Whole plant tissue analysis of canola at flowering shows micronutrients levels are sufficient at these levels: 29 parts per million for boron, 19 ppm for iron, 14 for manganese, 14 for zinc, 2.6 for copper and 0.02 for molybdenum.

Iron deficiency is rare for canola and most other field crops on the Prairies. A deficiency in copper is more likely to show up in cereals before canola. Manganese deficiency will show up first in oats. Zinc deficiencies will show up first in alfalfa, flax and beans before canola. Some bean growers in southern Alberta will add small amounts of zinc, particularly on sandy soils. Correcting any evident shortages in these other crops should take care of any potential deficiencies in canola. Molybdenum is more likely to show up in canola before any other crop, but molybdenum is needed at very low levels and deficiencies have not been observed in canola on the Prairies.