Pre-harvest intervals
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Try this handy tool: Spraytoswath.ca
Pre-harvest intervals
The quick and easy pre-harvest interval tool — the spray-to-swath calculator — helps you find a fungicide, insecticide or pre-harvest herbicide that fits your timeframe available.
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Pre-harvest intervals closing
Pre-harvest intervals
Insect threats are minimal at this stage of the season, but if you have late fields and an insect hot spot — say for bertha armyworm — the options are limited.
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The export effect: your spraying choice now may affect your worldwide market tomorrow
Pre-harvest intervals
Insects or disease may only have minor impacts on your yield at first, but spraying for them at the wrong time can have huge impacts on viable international markets by the end of the season. The canola industry works hard to keep a competitive, stable and open trade environment for canola and build strong relationships with customers around the world because international customers love clean Canadian canola. Make sure you help keep it clean by:
Respecting Pre-Harvest Intervals (PHIs)
Only using pesticides registered for use on canola
Following canola storage recommendations
Planting only R (resistant) or MR (moderately resistant) rated canola varieties
Not growing de-registered varieties -
PHI reminder
Pre-harvest intervals
Many canola fields are within 5 to 10 days of swathing, which limits the choices for insecticides based on pre-harvest intervals. Here are the pre-harvest intervals for insecticides registered for insect control in canola. Try the interactive PHI tool at www.spraytoswath.ca.
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Leave required time between spraying and cutting
Pre-harvest intervals
Pre-harvest interval (PHI) refers to the amount of time that must lapse (in days) after a pesticide application before the crop is cut. Cutting refers to swathing or straight combining. Each crop protection product has its own PHI, and the PHI for a specific product often vary by crop.
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Fungicide for late and long-flowering crops
Pre-harvest intervals
The risk of sclerotinia stem rot infection is still present on later crops that have not reached full flower, especially given the rain and high humidity in some regions this week. Highly variable crops may also be at “full flower” or their “most yellow” — other terms for 50% flower — for longer than typically expected, which also extends the risk.
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Pre-harvest intervals (PHIs) for insecticides
Pre-harvest intervals
Many canola fields are within 5 to 10 days of swathing, which limits the choices for insecticides — based on pre-harvest intervals. Here are the pre-harvest intervals for insecticides registered for insect control in canola. Try the interactive PHI tool at www.spraytoswath.ca.
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Read and follow pre-harvest intervals (PHIs)
Pre-harvest intervals
Pre-harvest interval (PHI) refers to the amount of time that must lapse (in days) after a pesticide application before the crop is cut (ie. swathed or straight cut). Failing to comply with a product’s pre-harvest interval is a contravention of the Pest Control Products Act (PCP). The PCP Act was put in place to protect human health and safety and the environment by regulating products used for the control of pests. It is important to adhere to the PHI to ensure no unacceptable chemical residues will be found in harvested seed. Adhering to the PHI ensures canola is safe for domestic consumption/use or export. With 85% of Canada’s canola crop exported around the world, it is critical that our canola meets the requirements of our export customers.
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Sprayed late, now what?
Pre-harvest intervals
Many canola crops are maturing earlier than expected this year, in many cases due to hot weather. This has put some growers in a bind. They had sprayed insecticide expecting to be outside the pre-harvest interval (PHI) required between application and the planned cutting date, but now as the crop approaches swathing timing they realize that not enough time has passed. It is important that growers follow the PHI for all products, otherwise harvested seed could exceed pesticide residue limits for key markets. Samples from all grower deliveries are saved, so any infraction can be traced back. So what to do?
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Alert: Must wait 21 days to cut after Lorsban application
Pre-harvest intervals
Growers who are using Lorsban or the generics Citadel, Pyrinex and Nufos to control insects are advised to observe the pre-harvest Interval (PHI) for this product. The PHI for this product is a minimum of 21 days before direct combining or 21 days before swathing. Our canola industry relies on exports and countries that we export to have strict regulations on the types of trace residues they allow in canola. These residues are detectable and could be traced back to individual farms in parts per billion. That amounts to nine seeds in a super-B. Please protect the quality of your load and our canola exports by always following PHIs.
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Quantify late-season insect threats
Pre-harvest intervals
In parts of central Alberta, lygus counts continue to exceed thresholds significantly (with counts as high as 450 lygus in 10 sweeps in some fields). In other areas, lygus numbers are just at or approaching threshold but the crop is very near to swathing. With these counts, growers are encouraged to resist the urge to simply spray and to be vigilant when scouting for lygus. Some insect species (eg. bertha armyworm) can decimate a crop if left uncontrolled, but
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Need to spray insects this late?
Pre-harvest intervals
Scouting for bertha armyworm can be tricky when scouting during the heat of the day. Click here to view a short scouting video with Canola Council Agronomist Tiffany Martinka. It can also be difficult to scout in a heavy crop but try these scouting tips: pull canola plants in a given area (ie. 1 meter […]
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Lygus scouting tips
Pre-harvest intervals
When sweep netting for lygus (shown above), it may seem that there are more lygus in the field than end up in the sweep net. This is expected. Sweep net thresholds were establishing knowing that lygus in the sweep nets represented only a certain percentage of lygus in the canopy. Stick to the thresholds, and follow sweep net techniques outlined in this article.