Girdling of early season ‘Mayfire’ nectarine trees

Abstract

The effect of four times of limb girdling on fruit and tree response was examined on ‘Mayfire’ nectarine (Prunus persica (L.) Batsch). Girdling prior to Stage II of fruit growth reduced the lag phase associated with Stage II, and caused peak fruit growth rates to occur earlier in the season than on later girdled or ungirdled trees. Optimum response was obtained by girdling prior to Stage II, when fruit seed length was approximately 10 mm. Girdling at this time increased fruit weight by 22.5% and more than doubled the percentage of fruit in the largest three size categories. Maturity, measured as soluble solids concentration, was increased by 42%. Shoot extension growth was reduced only by early girdling. Leaf weight per unit area was increased, and leaf nutrient concentrations were decreased by all girdling treatments. Leaf conductance to water vapour (g,) was not affected when measured 8 days prior to and 78 days after harvest. Fifteen days after harvest, g, was decreased in all girdling treatments.