Articles
CONTROLLING GROWTH OF SUPER-SPINDLE ‘GALA’/M.9 APPLE TREES WITH PROHEXADIONE-CALCIUM, NAA AND ETHEPHON
Article number
653_18
Pages
139 – 144
Language
English
Abstract
Prohexadione-Ca (PHD-Ca; a gibberellin biosynthesis inhibitor), NAA, and ethephon were applied alone and in combination to six-year-old super-spindle Gala/M.9 apple trees in a commercial high density orchard.
NAA was applied either as a paint or whole tree spray.
The paint treatment (1:2.5 Stop Drop® NAA/wallpaper paste) was applied to the fresh cut surface of the central leader 2.5 weeks after full bloom.
PHD-Ca (250 mg L-1 a.i.) was sprayed 4 weeks after full bloom.
Ten days later Stop Drop® NAA at 18 mg L-1 a.i. or ethephon at 300 mg L-1 a.i. were applied as whole tree sprays.
PHD-Ca effectively suppressed shoot elongation.
Fruit set was significantly increased by PHD-Ca but was decreased by ethephon.
PHD-Ca overcame this ethephon effect.
Mean fruit weight was reduced by PHD-Ca, and also by both NAA treatments with the spray treatment having the greater effect.
Fruit yield was increased by PHD-Ca but was substantially decreased by NAA and ethephon sprays.
PHD-Ca had no effects on fruit shape (L/D), firmness, and incidence of fruit stem-end russet.
PHD-Ca reduced soluble solids concentration and titratable acidity and delayed fruit maturity and harvest date.
Return flowering was reduced by PHD-Ca and NAA treatments (NAA paint was more inhibitive than NAA spray), but was promoted by ethephon.
NAA was applied either as a paint or whole tree spray.
The paint treatment (1:2.5 Stop Drop® NAA/wallpaper paste) was applied to the fresh cut surface of the central leader 2.5 weeks after full bloom.
PHD-Ca (250 mg L-1 a.i.) was sprayed 4 weeks after full bloom.
Ten days later Stop Drop® NAA at 18 mg L-1 a.i. or ethephon at 300 mg L-1 a.i. were applied as whole tree sprays.
PHD-Ca effectively suppressed shoot elongation.
Fruit set was significantly increased by PHD-Ca but was decreased by ethephon.
PHD-Ca overcame this ethephon effect.
Mean fruit weight was reduced by PHD-Ca, and also by both NAA treatments with the spray treatment having the greater effect.
Fruit yield was increased by PHD-Ca but was substantially decreased by NAA and ethephon sprays.
PHD-Ca had no effects on fruit shape (L/D), firmness, and incidence of fruit stem-end russet.
PHD-Ca reduced soluble solids concentration and titratable acidity and delayed fruit maturity and harvest date.
Return flowering was reduced by PHD-Ca and NAA treatments (NAA paint was more inhibitive than NAA spray), but was promoted by ethephon.
Authors
S. Guak, M. Beulah, N.E. Looney
Keywords
fruit quality, gibberellin biosynthesis inhibitor, Malus domestica, return flowering
Online Articles (31)