Year: 1993
Type: article
Abstract: Defoliation treatments on 2, 4, 8, and 16 whole canes per vine corresponding to an average defoliation intensity (DI) of 5.5, 10.2, 24.4, and 48.7% were carried out on kiwifruit (Actinidia deliciosa) vines with the same bud load and fruit number. Negative effects on fruit weight and concentration of soluble solids were recorded beginning at 24.4% DI. In comparison to undefoliated canes, the defoliated ones showed lower fruit weight from 10.2% DI and higher fruit drop from 24.4% DI. In the year following defoliation treatments, budburst was reduced at 24.4% DI, whereas differences between defoliated and undefoliated canes appeared at 48.7% DI. The percentage of fruiting shoots was reduced in comparison to the control, starting at 24.4% DI, but the differences between defoliated and undefoliated canes started at 10.2% DI. When there was an abundant supply of assimilates, translocation to fruits on defoliated canes occurred without limitations. When the availability of assimilates was reduced, the defoliated canes showed reduction of fruit weight, budburst, and flower differentiation more than the undefoliated ones. Therefore, in canopies with a large availability of assimilates, fruit position is not critical even if the leaf‐fruit ratio is lower than the vine average, with no negative effects on fruit weight, quality, and return bloom. In conditions of limited supply of assimilates, it is important to have the sink close to the source. Flower differentiation is sensitive to a lack of assimilates and to distance from source, but this draw‐back can be reduced by utilising replacement canes with a favourable source‐sink ratio.
Authors: A. Tombesi, E. Antognozzi, A. Palliotti
Institution: University of Perugia
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: bronze
OpenAlex ID: W2094586701