jan-feb-2021

With higher ground speeds and lower PTO/engine speeds, the sprayer will need have a new set of nozzles or a new flow rate set up for this application timing. Once the spur leaves are completely expanded, recalibrate the sprayer for spring summer work (slow ground speed and increase PTO/engine speeds). Frost Protection Irrigation systems and orchard floors should be prepared for frost management. Bare or close mowed, firm and moist orchard floors provide warmer conditions than those with tall vegetation. If freezing temperatures are forecast, and impact or micro- sprinklers available for active frost protection, water should go “on” when the wet bulb temperature is above the critical temperature for the stage of crop development in the orchard. Turn off sprinklers when wet bulb temperature rises above the critical temperature. If frost protection water goes on when standard thermometers read above the critical temperature – but the dew point is low and the wet bulb temperature is below the critical temperature – the water meant to warm the orchard by making ice will instead evaporate and drop the temperature. This could harm the crop. As the water runs, it will eventually raise the dew point and the temperature with it as ice forms, but the damage will have been done. For the same reason, the water shouldn’t be turned off until the wet bulb temperature is above the critical temperature. 5 1 J A N U A R Y – F E B R U A R Y 2 0 2 1