By Brent Flaten, PAg, CCA, Crops Extension Specialist
Proper pesticide application is an important management strategy that provides a benefit to producers in the pest reduction of weeds, diseases and insects, while providing acceptable crop tolerance. Proper pesticide application is also becoming increasingly important for global market access of our products. Social licence, society’s trust in and acceptance of modern food production, is based on “doing the right thing”. Proper pesticide application within an integrated pest management system is important in gaining that public trust.
First remember that using pesticides is only one of the strategies farmers have for pest management. Pesticides should always be used in conjunction with other pest management strategies, for an integrated approach. Integrated pest management combines cultural, chemical, mechanical and biological strategies. Cultural strategies involve managing ecosystems to minimize organisms from becoming economical pests. Examples include diverse crop rotations, use of winter crops, biennials or perennials, and variety selection with certain disease or insect tolerances. Mechanical strategies may include strategic tillage, mowing of weeds and grain cleaning. Biological strategies may include application of biological pesticides or general releases of natural insects to reduce weeds such as leafy spurge and scentless chamomile.
What is involved in proper pesticide application?
Proper pesticide application involves using the right product for the pest of concern, at the right rate for effective control, and at the right time for both the pest and crop. This requires following pesticide labels very carefully. Doing otherwise may not only reduce pest control or cause crop damage, it may cause increased pesticide residues in the harvested crop. Maximum residue limits (MRL’s), which include considerable safety margins, are considered by Health Canada to be safe pesticide residues in crops. They are a requirement for registration of pesticides and are based on labelled uses only, which include correct crop timing and pre-harvest intervals. Also, find and follow correct buffer zones on the label to avoid unacceptable contamination to surrounding areas.
Scout fields prior to pesticide application to identify potential pests and the crop stage, including when the crop is most susceptible to pest damage and the stage for proper pesticide application, if required. Also recognize that beneficial organisms such as parasites play an important role in controlling insect pests and certain weeds and diseases. Continue to scout to determine pest population changes and their potential damage to crops.
Use economic thresholds when deciding to take control measures for pests. Refer to the Guide to Crop Protection and other information sources for these thresholds. Eradication of pests is rarely a realistic goal or even a wishful goal. Saving pesticide applications for when pest numbers are above the economical threshold is cost effective, while reducing pesticide exposure and selection pressure towards pesticide resistance.
Refer to sprayers101.com for proper sprayer equipment, utilizing the right sprayer nozzle, speed, etc. for best pest control while reducing spray drift.
An emerging issue
An increasing issue has emerged lately in regards to MRL’s for our export markets. In the past, most countries followed an international standard MRL for any given pesticide on a particular crop. Now, more countries assess and establish their own pesticide MRL’s on crops they either produce or import. This change in practice means that a crop that was treated with a registered pesticide here in Canada, may not meet the importing country’s designated MRL if it is significantly lower than ours. Or, if the importing country has no MRL stated for a particular pesticide/crop use, the default is an MRL of zero. With the accuracy of modern detection equipment, this means the crop may not be allowed and the shipment rejected.
In summary, proper pesticide application as outlined above is important for improving production, market access and social licence.