A weekly report prepared by the staff of the Ministry of Agriculture, Food and Rural Affairs (OMAFRA). If you require further information, regarding this report, call the Elora Resource Centre at 519-846-0941. Office hours: 8:30am to 4:30pm. For technical information, call the Agricultural Information Contact Centre at 1-877-424-1300 or visit the OMAFRA website: www.ontario.ca/omafra.
RESISTANCE PREVENTION – MANAGING WESTERN BEAN CUTWORM AND MYCOTOXINS IN CORN
As the planting season begins, it is important to consider how best to manage western bean cutworm (WBC) damage this year and reduce the risk of resistance development.
Western bean cutworm has become a serious pest of corn in Eastern Canada resulting in yield loss and contamination of grain by mycotoxins. Only two main tools are now available to manage WBC: foliar insecticides and Vip3A transgenic corn.
With so few WBC management options, resistance to these tools is a real concern. In Ontario, WBC quickly developed resistance to the Cry1F Bt protein found in Herculex and SmartStax hybrids.
Herbicide tolerant weeds in Ontario are a good reminder of the importance of resistance management. The key to resistance management for WBC is rotation of management tools whether they are insecticidal or transgenic (Bt) modes of action.
Information on how to manage mycotoxins and reduce the risk of WBC resistance to insecticides or Viptera Bt corn hybrids can be found at http://fieldcropNews.com/wp-content/uploads/2018/05/WBC-Resistance-Management-Guidelines-2018.pdf.
Written by: Dr. Art Schaafsma and Dr. Jocelyn Smith, University of Guelph Ridgetown Campus and Tracey Baute, OMAFRA
GARLIC MUSTARD
Here is an invasive plant you should be aware of. It prefers damper locations but will thrive almost anywhere. Garlic Mustard has a two-year life cycle.
In the first year it only forms a rosette close to the ground but the second year it produces a stem with leaves about 3 feet tall topped with small white four-petal flowers that have the ability to self-pollinate and so are heavy seed setting plants.
It flowers in April and produces seed pods similar to the rest of the mustard family. Each pod can contain 10 to 20 seeds and there will possibly be 100 to 150 pods per plant that are shed during the summer and fall.
One seed can very quickly become a patch that keeps growing each year. Another trait is that it stays green throughout the winter and so is ready in the spring to complete its life cycle before other plants and so can out-compete the other desirable plants.
Garlic Mustard leaves contain a substance that is toxic to insects and animals that might otherwise keep it in control. As well the roots of Garlic Mustard produce a substance that changes the soil they grow in so it is not suited to grow other plants that would normally compete with it.
At least one species of butterfly is tricked into laying its eggs on this plant only to discover the larvae will not be able to eat the plant and so they perish. Another trick it has is to grow with an ‘S’ in the stem near the root and so if it is pulled the stock breaks at that point and the root remains with the opportunity to send up a new seed head.
I feel its biggest threat is to forests in that it produces a colony like a mat that in many ways discourages forest regeneration with the result the forest deteriorates.
Written by John C. Benham, weed inspector
COMING EVENTS
June 20 to 22 – Emerging Milk Quality Issues Conference. University of Guelph. For more information, visit www.oabp.ca or contact Ann Godkin at ann.godkin@ontario.ca.
