With the 6-year-old ´Fuji´ apple (Malus domestica BORKH.), gibberellin A₄ (GA₄) was lanoline pasted to the central fruit stalks of the fruit clusters at 3,000 ppm concentration 15 days after full bloom. Folithion (MEP) at 500 ppm was also sprayed 15, 20 and 25 days after full bloom resulted only 44.75% fruit cluster set and setting percentage was increased when MEP treatment was delayed. However, when GA₄ paste was treated to the peduncle of the fruit, fruit cluster setting percentage was increased to over 90 percent and 95 percent, respectively, when MEP was treated 20 and 25 days after full bloom.
Folithion treatment until 10 days after full bloom tended to inhibit during young fruit development temporarily, and GA₄ treatment, however, promoted.
The GA₄ treatment effect was evident even when MEP was treated.
However, the number of fruits remained per cluster was not significantly influenced by the treatment.
|