There are big differences between copper fungicides. Kocide, for example, can cause leaf injury to strawberry. Bravo fungicide can be applied twice before bloom to control Botrytis in strawberry leaves which then spreads to the flowers. Strawberry buds are especially susceptible to frost damage at this time of year. We automatically worry about strawberries when plants are in bloom, but tight green buds can also be damaged if temperatures are cold enough.
Strawberry flowers are most sensitive to frost injury immediately before and during opening.
At this stage, temperatures lower than -2C will cause injury. When buds are tightly closed, they can be injured at temeperatures of -5.5C or less. Overhead irrigation can help reduce frost injury on calm nights. Start irrigation when air temperatures in the lowest part of the field are several degrees warmer than the critical temperature for injury. Keep irrigation going until ice starts to melt.