Fruit size progress report – mid March 2011
March 2011 | Future Orchards® Business Development Program
This report explains how to interpret fruit-growth measurements correctly as harvest approaches. A single diameter measurement typically produces a curving growth line, with weekly diameter increase falling from around 4–5 mm early in the season to near 1 mm close to harvest. The report stresses that this does not necessarily mean the fruit’s absolute growth has slowed, because each millimetre represents more fruit volume as fruit becomes larger.
A Southern Victorian Rosy Glow block managed by Shaun Witchell is used as a case study. The block achieved 55 t/ha in third leaf with about 195 g average fruit size, then targeted 74 t/ha and 180 g in fourth leaf. Management was adjusted through the season: more fruit was retained at hand thinning and irrigation was moderated after early sizing indicated a risk of oversized fruit.
By mid-March, the crop was estimated at around 80 t/ha and growth had slowed to about 1 mm per week. Based on the measured 64.8 mm fruit diameter and anticipated harvest date, the report projected a harvest diameter near 70.1 mm, corresponding to roughly 177 g. The example demonstrates how monitoring can support fine-tuning of irrigation, crop load, reflective mulch, storage plans and market timing.
