Optimal Temperature for Foliar Spray
Foliar sprays—whether nutrients, pesticides, fungicides, bactericides, or acaricides—are temperature dependent. For optimal absorption, spray when temperatures are between 21-28°C (70-82°F).
Why temperature matters:
Stomata (leaf pores) close when it’s too hot to conserve water. Above 27°C (80°F), absorption drops significantly. Research by Beck’s PFR found that morning applications at 21°C (70°F) resulted in 18% more nitrogen and 28% more sulfur uptake compared to afternoon applications at 31°C (88°F).
Best practice: Spray early morning (7-10 AM) or late evening when temperatures are cooler and humidity is higher.
