The effect of spring frosts on fruit, nut and grape production needs little explanation.
Plant stimulants like Super Kelp and Vitazyme have been used extensively in Australia and overseas to improve the tolerance of crops to frost. Technically they act in a number of different ways, including improving brix levels and reducing the freezing point of plant cells. This is supported by independent research.
Super Kelp at 5L/ha in 1,000L water
Vitazyme at 1L/ha in 1,000L water
Ideally the first applications should be made 36 hours prior to the frost event, and both products can be mixed with 0.5% MKP to help strengthen the plant.
Repeat as required.
The pamphlet below has more details.