The effects of reflective cloth and adjusted fruit distribution on apricot fruit quality

Abstract

Apricot fruit harvested from lower, inner regions of the canopy are smaller and have lower soluble solids concentrations (SSC) than those from upper and outer canopy regions. A randomised, complete block trial was established using 'Cluthagold' apricot trees to investigate whether reflective cloth and/or adjustments to the distribution of fruit within these canopy regions could improve overall fruit quality. Extenday® reflective ground covers were placed along row aisles from pit hardening until harvest, with “uncovered” rows as controls. Fruit thinning was used to produce a standard fruit distribution within trees, typical of commercial orchards, spacing fruit approximately 8 cm apart along branches. An “adjusted fruit distribution” treatment was applied, with all fruit removed from the lower inner canopy zones and the equivalent number of additional fruit retained in the upper canopy. In all treatment combinations, fruit from the lower canopy regions were smaller and had lower SSC than fruit from the upper canopy. Reflective cloth increased light reflected up into the lower canopy and increased fruit weight (FW) and SSC of fruit in this part of the canopy; however, these fruit were still smaller and had lower SSC than fruit from the upper canopy of trees from any of the treatments. Adjusted fruit distribution did not affect FW or SSC of fruit grown in the upper canopy even though more fruit were located there. This corresponded to approximately 15% more fruit that were larger and had higher SSC than from standard trees. These results have identified potential short-term management techniques to increase fruit quality in older, more shaded apricot canopies.