engleski

Impact of Early Cropping on Vegetative Development and Productivity of "Golden Delicious" Apple Trees (Malus domestica Borkh)

Investigations of the influence of early cropping on productivity and vegetative development of newly established "Golden Delicious" /M.9 trees were conducted during three years after planting with the aim of determining the subsequent crop load dynamics according to different initial productivity of young trees. On the basis of the rate of natural fruit drop in the second growing year, three experimental groups were established: trees with intensive fruitlet natural June drop (group A) were further adjusted to 5 fruit tree– 1 ; medium fruitlet drop trees (group B) adjusted to 15 fruit tree– 1 ; and low fruitlet drop trees (group C) which were hand thinned to 25 fruit tree– 1. In the third growing year, the crop load was artificially thinned to 40, 60 or 80 fruit per tree. Trees of group A showed strong return bloom in the third growing year while weak flowering and low yield was observed in the fourth growing year (11– 28 fruit tree– 1). In contrast to group A, trees of group C presented a constantly increasing yield tendency with no biennial bearing pattern: 66 flower clusters in the third growing year which were hand adjusted to 40, 60 or 80 fruit tree– 1 gave nice return bloom and yield in the fourth growing year (63, 77 or 72 fruit tree– 1). Trees of group B adjusted to 40 or 60 fruit tree– 1 in the third growing season responded with medium return bloom and, consequently, appropriate yield in the fourth growing year, while 80 fruit tree– 1 adjustments or, on non-thinned trees, decreasing yield and biennial bearing tendency was observed. Trunk circumference increase on trees with higher crop load was smaller for all three bearing groups and was in the strongest negative correlation in the second year after planting the orchard.

apple; Malus domestica Borkh; crop load; growth; alternate bearing; productivity

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