Kiwifruit & apple nutrition for next season

Once fruit is removed, the plant undergoes a critical physiological shift from crop filling to reserve building. During this window, leaves remain active, roots often undergo a late season flush, and nutrients are actively translocated into buds, permanent wood, and roots prior to leaf senescence. In a high performing apple or kiwifruit orchard, post-harvest nutrition is not about pushing growth, but about replenishing reserves that will drive budburst, flowering, and early canopy development in the following spring.

Similar principles also apply in other perennial crops such as grapes and summerfruit, where early season growth is heavily dependent on stored nutrients. Two micro-nutirents that respond well to post harvest applications are zinc (Zn) and boron (B). Both are essential for bud development, flower fertility and pollination, fruit set, and early growth.

Research shows that when Zn and B are applied while leaves are still healthy, both nutrients are remobilised into buds during senescence. This makes post harvest one of the most reliable timings to lift bud nutrient status. An effective option for applying post-harvest B and Zn is Biolchim NutraGemma @ 2-3L/Ha. NutraGemma will supply B and Zn in a highly available form. By loading buds in autumn, reliance on spring uptake, which is often limited by cool springs, is significantly reduced.

Post harvest nitrogen (N) is often underutilised due to concerns about excessive vigour or soft fruit, yet research consistently shows that post-harvest applied N is stored, not expressed as growth.

N is stored as amino acids and proteins in the plant and plays a key role in floral bud strength, early shoot growth, and consistent fruit set. In the early spring, although the demand for N is high, soil temperatures are low and root uptake is slow and inconsistent. Due to these conditions, applying post-harvest foliar N is often more efficient than applying it on the soil as there is no leaching, uptake through leaf is quick, and there is rapid translocation into storage tissues. This means that N is readily available at bud break and for early canopy development.

For post-harvest applications, timing does matter. Leaf and tissue results collected during the season should guide post-harvest programmes. Seasonal conditions, hot, dry years versus cool, wet seasons, strongly influence nutrient drawdown and replacement needs. Applying the same programme every year risks under or over supplying nutrients. Crucially, foliar nutrition must be applied immediately post harvest while leaves are green and functional. Once yellowing and leaf drop begin, uptake efficiency falls sharply.

Yield and quality potential for the coming season is often determined in the weeks after harvest. Strategic post-harvest nutrition in apples and kiwifruit sits at the top of the list for building strong reserves, improving spring performance, and delivering consistent results year on year.