PRINCIPLES OF THINNING IN FRUIT TREE CROPS - NEEDS AND NOVELTIES

Abstract

Fruit trees bear an abundance of flowers, which they cannot support until fruit maturation; ca. 7% of flowers are necessary in apple for a sufficient harvest while 25% of flowers are necessary in peach. Thinning is hence a prerequisite in fruit crops i) to achieve high quality fruit with sufficient size and colouration for class I marketing including sugar (as a parameter for taste) and sufficient firmness (as a parameter for good storability), ii) to reduce labour-intense hand thinning and iii) to overcome alternate bearing (change of low and high yielding years) by providing regular moderate yields.