Abstract
Adverse effects of gibberellin applications on pear trees after frost such as small fruit size, abnormal fruit shape and poor return bloom are often attributed both to the sole use of GA3 and its overdose. It is unclear whether protection against spring frosts before flower opening is more efficient when GA is applied directly after frost, i.e. before flower opening, or at full bloom or both. In April 2003, early spring frosts at Klein-Altendorf near Bonn, Germany damaged ca. 88% flowers of the early flowering cv. Alexander Lucas, 64% of cv. Conference and ca. 25% of flowers of the later flowering cv. Comice pears. Hence, the objective of the present work was to investigate the optimum timing of the application of low doses of the combined GA3 and GA4 + 7 to improve parthenocarpic fruit set in pears, while maximising fruit quality and size for trees affected by a severe spring frost before full bloom. Return bloom was also considered and quantified. Frost-affected pear trees were treated with gibberellin GA3+GA4 + 7, either immediately after the frost, at the white bud stage, or at full bloom or both to improve parthenocarpic set. Early flowering cv. Alexander Lucas pear was most affected by the early spring frost, but lost only 25% of fruitlets at June drop, irrespective of GA treatment. June drop was, however, severe in the two other cultivars least affected by frost, i.e. by 33% in cv. ‘Conference’ and 55% in cv. Comice. Both initial and final fruit set were significantly increased by a combined application of GA3+GA4 + 7 at full bloom, without affecting return bloom, but June drop was also enhanced by GA application. The largest positive effect of GA application on fruit yield, an additional 2 kg of fruit per tree equivalent to €1200/ha, was apparent with the cv. Alexander Lucas, i.e. the cultivar most affected by frost. There was no loss in fruit quality viz fruit size after any of the GA applications with any of the pear cultivars examined and no increase in abnormally-shaped, elongated fruit.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
G. Browning (1990) ArticleTitleGibberellin-induced parthenocarpic development of pedicels of Pyrus communis L. cv. Conference J. Hort. Sci. 66 177–181
F.G. Dennis SuffixJr. J.P. Nitsch (1966) ArticleTitleIdentification of gibberellins A4 and A7 in immature apple seeds Nature (London) 211 781–782 Occurrence Handle1:CAS:528:DyaF28XkvFCjsrg%3D
D.W. Greene (2000) ArticleTitleReducing floral initiation and return bloom in pome fruit trees – applications and implications HortTechnology 10 740–743 Occurrence Handle1:CAS:528:DC%2BD3cXnslCjtLs%3D
G.E. Honeyhome (1996) ArticleTitleThe effect of gibberellin-containing growth regulators on fruitset and preharvest quality of Forelle pears Deciduous Fruit Grower 46 166–172
Y. Inomata S. Murase S. Oikawa T. Shinokawa K. Suzuki (1992) ArticleTitleEffect of gibberellin treatment on flowers of Japanese pear (Pyrus pyrifolia Nakai) after late frost damage Bull. Fruit Tree Research Station 23 123–136
L.C. Luckwill (1960) ArticleTitleThe effect of gibberellic acid on fruit set in apples and pears Ann. Rep. Long Ashton Res. Sta. for 1959 59–64
L.C. Luckwill (1961) ArticleTitleThe effect of gibberellic acid on the cropping of pears following frost damage Ann. Rep. Long Ashton Res. Sta. for 1961 61–66
L.C. Luckwill P. Weaver J. MacMillan (1969) ArticleTitleGibberellins and other growth hormones in apple seeds J. Hort. Sci. 44 413–424 Occurrence Handle1:CAS:528:DyaE3cXkt1SjtQ%3D%3D
I. Modlibowska (1961) ArticleTitleStimulation of fruit development in frost damaged pears Rep. E. Malling Res. Sta. for 1960 46–48
H. Yamada K. Nakajima Y. Yamazawa I. Kuroi (1991) ArticleTitleEffect of pollination and gibberellin treatments on fruit set and development of the European pear (Pyrus communis L. var. sativa DC.) cv. Le Lectier J. Jpn. Soc. Hortic. Sci. 60 267–273 Occurrence Handle10.2503/jjshs.60.267 Occurrence Handle1:CAS:528:DyaK3MXmsFShtL4%3D
S.J. Wertheim J.H. Bootsma (1992) ArticleTitleGibberellin-dosing can perhaps be lower Fruiteelt 82 14–16
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Yarushnykov, V.V., Blanke, M.M. Alleviation of frost damage to pear flowers by application of gibberellin. Plant Growth Regul 45, 21–27 (2005). https://doi.org/10.1007/s10725-004-6893-5
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s10725-004-6893-5