ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Response of 'Comice' pear trees to a postharvest urea spray.

Sanchez, E. E.; Righetti, T. L.; Sugar, D.; Lombard, P. B.;

Journal of Horticultural Science Year: 1990 Vol: 65 Issue: 5 Pages: 541-546 Ref: 24 ref.

1990

บทคัดย่อ

A single postharvest 5 or 10% urea spray increased N content in 1-year-old bark and wood and in flowers and flower buds of 6-year-old Comice pear trees on Provence quince BA29 pear rootstocks and trained to a multiple leader in an experiment in 1987. In 1988, there was also an increase in N in 1-year-old bark and wood but not in the N content of flower buds and flowers. Fruit set was not significantly increased in either year. Urea labelled with 15N was applied to branches and individual spurs immediately after harvest. When the 15 N-urea was applied to branches, the next season's flower buds had 12% of their N derived from the fertilizer (NFF), but when urea was applied to individual spurs only 8% NFF was detected. Remobilization of labelled N from treated to adjacent spurs resulted in less NFF than would occur if all spurs on the same branch received labelled N. Flower clusters distal and basal to the spurs treated with labelled 15N absorbed considerable amounts of N from the labelled spray. However, harvest analysis of spur leaves and fruits adjacent to and distant from treated spurs and branches revealed that urea was only locally mobilized in the tree. In trees receiving postharvest soil N applications, only 2% NFF was detected in flower buds. It is concluded that pear production can benefit from postharvest urea application to trees, particularly if tree N status is low.