In 1992, branches on `Triple Red Delicious'/M.7 were girdled. A factorial of treatments (control, 9mm girdle-uncovered, 9mm girdle-covered) and timings: 0, 15, 30, 60, & 90 days after full bloom(DAFB) was used. With `Golden Delicious'1M.7, branch treatments were: control, score, and 6mm, 9mm, & 12 mm covered girdles, each applied at 0, 15, 30, & 60 DAFB. In 1993, treatments were: control, 9mm uncovered girdle, & pruning saw cut; each was applied 0, 7, 14, and 21 DAFB. Each girdle was a complete ring of bark; scoring was a knife cut through the bark.
The 2 cultivars responded similarly to girdling. Effects were greatest to treatments at 0-30 DAFB, and included increased fruit set or retention, temporary suppression of vegetative growth, and increased levels of soluble solids in the fruit. Treatments affected starch levels in the fruit and flesh firmness, but these effects were inconsistent.