Translator Disclaimer
21 January 2017 Interactive effects of 6-BA, GA4 7, and prohexadione-calcium on Gala apples
J.A. Cline
Author Affiliations +
Abstract

Gibberellic acid (GA4 7) and the cytokinin 6-benzyladenine (6-BA) are used during bloom and fruit set to reduce russeting and improve typiness of select apple cultivars. The gibberellin synthesis inhibitor prohexadione-calcium (P-Ca) is used at the same developmental stage to reduce vegetative growth and susceptibility to fireblight. The use of GA4 7/6-BA for enhancing the typiness of Gala apples and the interaction of GA4 7/6-BA and P-Ca was investigated in a 2-yr experiment on mature Royal Gala/Bud 9 trees. Six treatments were imposed: (i) untreated control; (ii) 5.5 mg L-1 of GA4 7 and 6-BA; (iii) 11 mg L-1 of GA4 7 and 6-BA; (iv) 21 mg L-1 of GA4 7 and 6-BA; (v) 123 mg L-1 P-Ca; and (vi) a tank mixture of 21 mg L-1 GA4 7/6-BA and 123 mg L-1 P-Ca. Trees treated with P-Ca had 21%–45% less growth than the untreated trees or trees treated with GA4 7/6-BA. In one of two years, the addition of GA4 7 and 6-BA tank-mixed with P-Ca reduced the efficacy of P-Ca on shoot growth. GA4 7/6-BA decreased soluble solids and fruit firmness in 1 yr, suggesting a delay in fruit maturity. P-Ca alone reduced scarf skin by 7%–10%; however, this effect was negated when combined with GA4 7 6-BA in one of the two years. GA4 7 6-BA increased fruit typiness and length to diameter ratios.

Copyright remains with the author(s) or their institution(s). Permission for reuse (free in most cases) can be obtained from RightsLink.
J.A. Cline "Interactive effects of 6-BA, GA4 7, and prohexadione-calcium on Gala apples," Canadian Journal of Plant Science 97(4), 632-644, (21 January 2017). https://doi.org/10.1139/cjps-2016-0314
Received: 7 October 2016; Accepted: 1 December 2016; Published: 21 January 2017
JOURNAL ARTICLE
13 PAGES


SHARE
ARTICLE IMPACT
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top