HAND THINNING IN THE APPLE CULTIVARS ‘GALA’, ‘GOLDEN DELICIOUS’ AND ‘FUJI’ IN THE STATE OF SANTA CATARINA, SOUTH BRAZIL

Various hand thinning methods were tested on the cultivars ‘Gala’, ‘Golden Delicious’ and ‘Fuji’. The treatments included thinning within the clusters, selective thinning according to nutrient potential of the clusters, thinning to threshold sizes and unthinned controls.
In the cvs. ‘Gala’ and ‘Fuji’ these treatments were compared with chemical thinning applying in the first cv. naphthaleneacetamide (NAAm; 50 mg l^-1) at 5 days after full bloom (AFB) and in the latter cv. naphthaleneacetic acid (NAA; 15 mg 1^-1) plus mineral oil (2.5 ml l^-1) at 10 days AFB. From an economic point of view selective thinning according to nutrient potential of the clusters gave the best results in all three cultivars.
Only in the cv. ‘Golden Delicious’ was selective size thinning superior in comparison with systematic thinning within the clusters.
In the cv. ‘Gala’ chemical thinning with NAAm at 5 days AFB was less profitable than the best hand thinning method.
In the cv. ‘Fuji’ a spray of NAA plus mineral oil at 10 days AFB resulted in the highest return of all thinning treatments tested.

International Workshop on Apple Culture in the Tropics and Subtropics

A. Ebert

https://doi.org/10.17660/ActaHortic.1988.232.21