1. You have grasshoppers at thresholds in your canola and your wheat. You decide to spray canola with chlorpyrifos (Lorsban, Pyrinex, Nufos, Citadel, Pyrifos, MPOWER Krypton) because spraytoswath.ca says the pre-harvest interval (PHI) for each of these products is 21 days. You then move over to wheat, planning to spray the same stuff. But wait! What is the PHI (in days) for chlorpyrifos in wheat?

2. You expect to cut canola in LESS than 21 days but you have an insect that needs to be sprayed. Using the "Have a deadline?" tool at spraytoswath.ca, how many product options (brands and formulations) do you have with a PHI of less than 21 days?

3. You can use this active ingredient to control insect pests in canola fields, but as noted at keepingitclean.ca, this same active ingredient cannot be used to treat canola bins or harvested canola as it goes into bins. What is it?