The effect of reflective cloth on light distribution and fruit quality in a kiwifruit orchard

Typical canopy architecture of a kiwifruit vine can generate a large degree of self-shading, as the uppermost leaves intercept the vast majority of photosynthetically active radiation (PAR) and shade the lower layers of the canopy. Reflective cloth is a tool that can be used to reflect the light that passes through large gaps between plants, falls onto the ground and back up onto shaded leaves. The current study assessed the effects of two different reflective cloth installations (Full: reflective cloth covering the majority of the inter-row sward, and Strip: 1-m wide strips of reflective cloth laid on the sward underneath the gap between male and female canopies) on fruit quality and on light distribution around the vine. Trials were performed in two commercial Actinidia chinensis var. chinensis ‘Zesy002’ kiwifruit orchards (Orchard X and Orchard Y). At Orchard Y, both Full and Strip treatments increased (albeit not significantly) the proportional changes in fruit fresh weight m^‑2 and dry weight m^‑2 by 12-17% and 5-10%, respectively, compared with the control (i.e., grass). However, no effects of treatment on fruit quality were observed at Orchard X, despite both treatments increasing light dispersal under the canopy, compared with the control. We suggest that the difference in fruit quality between orchards was because reflective cloth at Orchard Y reflected approximately double the amount of light reflected at Orchard X. Less light was reflected at Orchard X because the strung-cane system reduced the amount of incident light falling onto the ground. This study highlights the value of small increases in light distribution in a plant canopy, and indicates the potential for further improvements in kiwifruit quality if canopy management is optimised.