<abstract xmlns="http://www.w3.org/1999/xhtml"> Growth retardants have great potential to balance between vegetative and reproductive growth. To assess the effects of prohexadione-calcium (Pro-Ca, Regalis) on reproductive and vegetative growth, return bloom, fruit set, and also fruit quality in ‘Golden Delicious’ apple grafted on M.9 rootstock, an experiment was performed during 2010-2012. The applications of 125 mg dm-3 Pro-Ca on the same trees in each year resulted in a 40-43% shoot length reducing. Internodes length decreased with Pro-Ca at about 30%, while total node number was unaffected. Results indicate that Pro-Ca applications have no effects on tree trunk growth, flowering, yield, fruit set and development. Pro-Ca also didn’t have any negative impact on fruit quality during the three consecutive years. Moreover, Pro-Ca resulted in higher fruit size compared to control in the third year of trial. The results of this experiment clearly suggest that fruit growers can use Pro- Ca for the control of vegetative growth without having any negative effects on fruit quality and yield parameters. Once a full canopy has been achieved, annual shoot growth can be suppressed in the range of 20 to 30 cm with 125 mg dm-3 Pro-Ca treatment in ‘Golden Delicious’ apple trees.</abstract>

Growth retardants have great potential to balance between vegetative and reproductive growth. To assess the effects of prohexadione-calcium (Pro-Ca, Regalis) on reproductive and vegetative growth, return bloom, fruit set, and also fruit quality in ‘Golden Delicious’ apple grafted on M.9 rootstock, an experiment was performed during 2010-2012. The applications of 125 mg dm-3 Pro-Ca on the same trees in each year resulted in a 40-43% shoot length reducing. Internodes length decreased with Pro-Ca at about 30%, while total node number was unaffected. Results indicate that Pro-Ca applications have no effects on tree trunk growth, flowering, yield, fruit set and development. Pro-Ca also didn’t have any negative impact on fruit quality during the three consecutive years. Moreover, Pro-Ca resulted in higher fruit size compared to control in the third year of trial. The results of this experiment clearly suggest that fruit growers can use Pro- Ca for the control of vegetative growth without having any negative effects on fruit quality and yield parameters. Once a full canopy has been achieved, annual shoot growth can be suppressed in the range of 20 to 30 cm with 125 mg dm-3 Pro-Ca treatment in ‘Golden Delicious’ apple trees.

Impact of Repeated Yearly Applications of Prohexadione-Calcium On Vegetative and Reproductive Growth of ‘Golden Delicious’/M.9 Apple Trees

Journal of Horticultural Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Growth retardants have great potential to balance between vegetative and reproductive growth. To assess the effects of prohexadione-calcium (Pro-Ca, Regalis)...

Impact of Repeated Yearly Applications of Prohexadione-Calcium On Vegetative and Reproductive Growth of ‘Golden Delicious’/M.9 Apple Trees

Published Online: Jun 30, 2017

Page range: 47 - 54

Received: Oct 01, 2016

Accepted: Apr 01, 2017

DOI: https://doi.org/10.1515/johr-2017-0005

Keywords
alternate bearing, fruit quality, growth retardant, internode length, return bloom, shoot growth

© by A. Nilgün Atay

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Impact of Repeated Yearly Applications of Prohexadione-Calcium On Vegetative and Reproductive Growth of ‘Golden Delicious’/M.9 Apple Trees

Published Online: Jun 30, 2017

Page range: 47 - 54

Received: Oct 01, 2016

Accepted: Apr 01, 2017

DOI: https://doi.org/10.1515/johr-2017-0005

Keywordsalternate bearing, fruit quality, growth retardant, internode length, return bloom, shoot growth

© by A. Nilgün Atay

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
alternate bearing, fruit quality, growth retardant, internode length, return bloom, shoot growth