The fruit setting process can be conventionally divided into two stages. In the first stage, the flower is pollinated and fertilized, in the second of the fertilized flower a fruit set develops. Not found, that the pruning may have an effect on the pollination and fertilization of the flower, it is known, however, that pruning influences the development and maintenance of fruit buds on the tree.
As you know, some of the fertilized fruitlets fall off. The dropping of the fruitlets is related to their mutual competition for food, as well as competition between growing shoots and seedlings. Pruning reducing the number of flower buds, and therefore he makes flowers, that there is less competition between the unions, therefore a greater percentage of them remain on the tree. The positive effect of pruning on the persistence of fruit sets can be easily demonstrated in older trees, which naturally have a lot of flowers and fruitlets (table).
Table. Number of fruit set in 8-year-old apple trees, weakly and strongly cut (according to A. Mica, A. Jackiewicz, M. Potocka)
| Variety | Number of fruit set per 100 inflorescences1
weak cut | strong cut |
|
| Mclntosh | 77 | 122 |
| Bankroft | 53 | 62 |
| Jonathan | 83 | 112 |
| Golden Delicious | 120 | 195 |
1 One apple inflorescence contains on average 5 flowers
In young trees, the shedding of fruit buds is sometimes caused by the competition of intensively growing shoots, which have a greater ability to absorb food than the fruit. If in the period of intensive shoot growth (May and June) their tops are pinched several times, the greater percentage of the buds remains on the tree.