Shoot Flush Relationship with Productivity in 'Valencia Late'Orange

摘要

Twelve-year-old ' Valencia late' [ Citrus sinensis (L.)Osb. ] orange hand-pruned trees were irrigated and non-irrigated during six years to evaluate the alternated bearing production and to quantify the yield components in the northwest of Uruguay. Crop load and fruit number was related with flush growth intensity and flower intensity in individual trees consecutively for 6 years. In each tree the flowering intensity was inversely related to the previous crop load (r2=0. 71) , and the number of fruits during the season directly related with the flowering intensity (r2=0.69 ). The total number of shoots per m3 of canopy decreased by the number of fruits on the tree in well- watered trees as in non- irrigated ones. Additionally the number of shoot on the canopy was directly related with the flowering intensity during the following season. The amplitude in crop load variation between years was bigger in non-irrigated trees than in well- watered trees. Irrigation reduced the alternated magnitude but the alternation in flowering intensity and shoot number remained. Supplementary water significantly reduced the alternation of fruit load but does not eliminate it. Thus, the excesses of flowers without the reduction of the fruit number produced overload, which induced the trees in an alternate production throughout the following year.