Bearing branch units developed on branches hedged during flowering produce large 'Washington' Navel (Citrus Sinensis L. Osbeck) oranges

Abstract

Citrus growers in Australia need to be able to produce large fruit size for premium returns in domestic and overseas markets. Therefore, it is important to manipulate the tree canopy by hedging in a "heavy-flowering" year to decrease crop load and enhance fruit size the following year. A two-year study was conducted on the relationship of fruit size to different inflorescence types that developed on bearing branch units (BBU) that developed in the summer following mechanical hedging during flowering in spring compared with non-hedged branches. Spring hedging produced a "stronger" vegetative growth flush compared to the non-hedged branches: BBU developing on hedged branches produced more sprouts, flowers, leafy inflorescences and 3.6 to 5 mm larger fruit size than BBU from non-hedged branches. Moderate severity mechanical hedging in the spring of "on-flowering" years is recommended as a practical means to manage the existing crop load, enhance fruit size and alleviate alternate bearing for the following year. Copyright © Taylor & Francis Group, LLC.