By Erica Faber – Technical Manager
As we progress into Winter, newly planted trees may be showing some signs of stress with the colder, wetter weather as well as the development of flower buds. Nutrient uptake through the roots slows down as the soil temperatures become colder and the rate of transpiration decreases. Nutrient deficiencies may start becoming apparent due to this as well as the higher demand for certain nutrients at key phenological stages eg. flower development.
Yellowing and distortion of leaves may be notable. Blotchy or mottled interveinal yellowing and smaller, rounder cup shaped leaves are typical symptom of Zinc deficiency which may be noticed this time of year. Other trace elements that are in higher demand at this time of year are also Boron and Magnesium. Ensure that these trace elements are part of your foliar fertiliser program. Bud-Wiser is an example of a foliar product that delivers Zinc, Boron and Magnesium and can be incorporated into your program depending on compatibility with the other products you are spraying.