Updated Canola Production

Producers, agricultural consultants and others interested in agriculture can use a new updated canola production (spiral bound) pocket field guide to obtain the latest information about canola production. The previous field guide was published in 2005 and was in need of major updates, especially on the canola diseases of blackleg and sclerontina, canola insects, weed management and desiccation at harvest, and other management issues.

NDSU State Extension staff and other canola specialists wrote the revised and reviewed guide.

The field guide also has a photo section at the back of the publication with pictures of weeds, insects, and diseases.

The publication is a comprehensive guide for those considering or growing canola. Some of the topics discussed include canola varieties; growth stages; field selection; planting dates; soil fertility requirements; weed, insect, and disease management and control; frost tolerance and damage; swathing and harvest management; resource contacts and publications; and useful websites.

North Dakota growers can order a free copy of the pocket guide from the Northern Canola Growers Association by phone at 897-585-1671 or email [email protected].

Our office also has a limited number of copies which can be distributed upon request. A web version of the guide can be found at http://www.ag.ndsu.edu/pubs/plantsci/crops/a1280.pdf.

Scout for Pea Aphids

Pea aphids are fairly abundant this year as are other species of aphids, so pea fields should be scouted during flowering. They are small, about 1/8+ inch long and pale green. Pea aphid feeding during the flowering and early pod stage can result in lower yields due to less seed formation and smaller seed size. Protein content and other quality issues do not appear to be affected.

Scouting for aphids in pea is conducted using either a sweep net or examining the number of aphids per plant tip when 50-75% of the peas are flowering. Take ten 180º sweeps using a 15-inch sweep net or check at least five 8-inch plant tips from four different locations in the field. Population estimates should be calculated by averaging counts taken from four separate areas of the field.

Economic thresholds may vary depending on the value of the crops and cost of control, as well as variation in potential seed weight caused by variation in precipitation and heat stress. The economic threshold in peas is 2-3 aphids per 8-inch plant tips, or 9-12 aphids per sweep (or 90-120 aphids per 10 sweeps,) at flowering. If the economic threshold is exceeded, a single application of insecticide when 50% of plants have produced some young pods will protect the crop against yield loss and be cost-effective. Varieties of peas may also vary in their tolerance to feeding by pea aphids, thus economic injury levels may differ between varieties. However, research has shown that insecticides applied when pods first form protect pea yield better than earlier or later applications. Control at the early pod stage provides protection through the pod formation and elongation stages, which are very sensitive to aphid damage.

A listing of insecticides registered for pea aphid control in field peas is available from the ND Field Crop Insect Management Guide 2011, E-1143, NDSU Extension Service at: http://www.ag.ndsu.edu/pubs/plantsci/pests/e1143w1.htm.