Role of Zinc in Pip Fruit Production

Zinc functions in many enzyme systems and biochemical functions including acting as a precursor of indoleacetic acid which is involved in shoot elongation. The micronutrient thus plays a major part in bud development and flowering. Poor zinc supply restricts leaf and bud growth and development, leading to bare bark or rosettes of spindly leaves.

Zinc effect at growth stages

Stage Zinc effect
Bud Burst – Start of Flowering To optimize bud burst and early leaf development
Post Harvest Replenish reserves and strengthen new buds
See more on Apple Growth Stages.

General Guidelines for Zinc Application

Soil applications need to be applied or banded around the root zone, but uptake is limited and doesn’t occur until 4/5 leaves are unfolded in the spring. 

Care is needed in choosing the right form of foliar-applied zinc so as to minimize damage to young leaves and the fruit.

Zinc Deficiencies in Apples

Symptoms occur in the spring and include chlorosis of the youngest shoot leaves, which are stunted and narrower than normal – ‘little leaf’.

Yellowing occurs between leaf veins and is less symmetrical than, for example manganese deficiency. The leaves may show a wavy margin. Blind bud and rosetting can also occur. Leaf symptoms are not strong in apples compared to other fruit trees.

Extreme deficiency results in shoot defoliation and the production of misshapen and poorly colored apples.