FRUIT SET AND PARTHENOCARPIC FRUITS AS AFFECTED BY THE USE OF WYE MIXTURE IN GOLDEN DELICIOUS APPLE CULTIVAR
This experiment was carried out in Videira, State of Santa Catarina, southern Brazil, in order to investigate the effect of a mixture of growth regulators (Wye mixture) on the fruit-set and parthenocarpic fruit formation of Golden Delicious apples after being sprayed with mineral oil - DNOC for breaking dormancy purposes. Twenty plants were used. In each one a selected branch stablished the experimental unit being the branch randomly allocated within the tree. For the first year, 1977, the treatments were sprayed with the Wye mixture as follows: 1 – 50% of the flowers being opened; 2 - full bloom; 3 - petal fall and 4 - control. For the second year, 1978, the branches were treated as follows: 1 - full bloom; 2 – 50% petal fall; 3 – 100% petal fall; 4 - flowers decapitated following treatment; 5 - control. The association of growth regulators known as "Wye mixture" consisted of 2-naphthoxiacetic acid 50ppm (NOXA), gibberellic acid 200ppm (GA3) and NN-Diphenylurea 300ppm (DPU). Spraying of this mixture greatly increased the set of fruits in the first year as compared to the results achieved on the control. It was also shown that parthenocarpic fruits could be obtained by using this mixture at any flower stage. The fruit set for the treatments in the second year were satisfactory apart from the decapitated flowers. It was also found the formation of parthenocarpic fruits for the Wye mixture treated trees. No significant differences were found among the mean fruit weights. The fruits from the decapitated treated flowers were longer than the others.
Fortes, G.R.d. and Petri, J.L. (1983). FRUIT SET AND PARTHENOCARPIC FRUITS AS AFFECTED BY THE USE OF WYE MIXTURE IN GOLDEN DELICIOUS APPLE CULTIVAR. Acta Hortic. 137, 335-342