Effect of mineral oil and hydrogen' cyanamide concentration on dormancy breaking in 'Golden Delicious' apple trees
Author
dc.contributor.author
Sagredo Urra, Karen
Author
dc.contributor.author
Theron, Karen
Author
dc.contributor.author
Cook, Nigel C.
Admission date
dc.date.accessioned
2015-10-07T20:04:46Z
Available date
dc.date.available
2015-10-07T20:04:46Z
Publication date
dc.date.issued
2005
Cita de ítem
dc.identifier.citation
South African Journal of Plant and Soil 2005, 22(4)
en_US
Identifier
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DOI: 10.1080/02571862.2005.10634716
Identifier
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https://repositorio.uchile.cl/handle/2250/134233
Abstract
dc.description.abstract
South African production are!3S receive insufficient winter chilling for apple production, necessitating the use of
artificial means to break dormancy_ Hydrogen cyanamide (HC) alone or in combination with mineral oil (oil) is
used as a rest-breaking agent in many deciduous species. The effect of different concentrations of HC and oil
on budburst, yield, fruit quality and vegetative growth of mature 'Golden Delicious' apple trees were evaluated;
the objective was to determine the presence of interaction between the rest-breaking effect of HC and oil when
combined at varied concentrations, and to determine appropriate concentrations of HC and oil, to enhance budburst,
yield and fruit quality. Three trials were conducted in the Elgin valley (34 oS, 300 m) of the Western Cape,
South Africa, in 1999 and 2000. The first trial evaluated four concentrations (0, 0.5, 1 and 2%) of Dormex®
(hydrogen cyanamide 520 g·L-1) in combination with four concentrations of mineral oil (0, 1, 2, and 4%). The
second trial used three concentrations (1, 2 and 4%) of Dormex® in combination with three concentrations of
mineral oil (1, 2, 4%), plus an unsprayed control, and a treatment of 6% of DNOC Winter Oil®. The third trial
included five treatments: 0.5% Dormex® + 3% oil, 1 % Dormex® + 4% oil, 6% DNOC Winter Oi/®, 6% oil and a
non-sprayed contro/. All of the treatments were applied at the first visible signs of bud burst. No synergistic effect
was observed between oil and HC. Mineral oil at 4% plus 1 to 2% Dormex® were sufficient to break dormancy.
Dormex® at 4% (2.08% HC) reduced fruit set and yield.