EFFECTS OF CROPLOAD ON ANNUAL GROWTH AND DRY MATTER PARTITIONING IN YOUNG KIWI VINES

Four-year-old (second year of production) ‘Hayward’ vines trained to T-bar and spaced at 4.5 m x 1.5 m were thinned after fruit-set to 4 different croploads: without fruit (NF), severely thinned (ST), medium thinned (MT) and not thinned (NT), corresponding to a progressively increasing fruit-shoot ratio of 0, 0.45, 0.93 and 1.72 respectively.

Thinning had little effect on fruit size (only 5 g/fruit between ST and NT), while yield per vine decreased by roughly 6 kg/vine, corresponding to 7.9 MT/ha, between NT and MT and between MT and ST.

The presence of fruit induced a noteworthy change in manner of vine growth.
At the end of the growing season, the NT treatment showed 19% lower leaf area and total dry weight, excluding fruits, compared to NF. In the latter treatment, 34% of canes were self terminated as compared to 24% in NT. The ratio between the below-ground and above ground parts (g d. w./g. d.w.) was found to be markedly higher (0.59) in NF as compared to NT (0.46) but no differences were found between treatments in the ‘root/leaf area’ ratio.

Soluble carbohydrates and starch concentration was noticeably greater in NF than in NT in all vine parts.

III International Symposium on Kiwifruit

C. Xiloyannis, R. Massai, D. Piccotino, M. Raffaelli, M. Bovo

https://doi.org/10.17660/ActaHortic.1997.444.31