EFFECTS OF THINNING IN A LONG-TERM TRIAL WITH SIX APPLE CULTIVARS ON YIELD AND FRUIT SIZE

During the years 1982 – 1992 a thinning trial with six apple cultivars was carried out.
Four treatments were applied to the trees every year, provided bloom density was satisfactory.
The effects of these treatments on total crop, alternate bearing, fruit size distribution and quantity of fruit in 5mm-classes between 55 and 100mm were recorded.
From the results the monetary value of the crop in the different plots was calculated.

The results clearly demonstrate that yields are and must be markedly reduced in the on-years.
Though regularity of cropping was oftenly improved by thinning, the loss of fruit could not be compensated by it.
This was also true for the improvement of fruit size: there was some compensation for the loss of small fruit, but not enough to yield the same fruit quantity as in control trees.
The early hand-thinning method always gave the best results as regularity of cropping, yield of marketable fruit and monetary value of the crop are considered.
But this method costs so much time that it is impracticable for growers.

II Workshop on Pome Fruit

H. Link

Malus domestica Borkh., alternate bearing, economics

https://doi.org/10.17660/ActaHortic.1998.466.10