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Developments in the chemical thinning of apple and pear

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Abstract

A literature review is presented on past and present experienceswith chemical flower and fruit thinning of apple and pear, amplifiedwith some data of recent trials with known and new flower thinners(mainly ethephon and ammonium thiosulphate) and fruit thinners (mainly1-napthylacetic acid (NAA), its amide (NAAm), carbaryl, ethephon,conjugates of NAA and NAAm and benzyladenine). Chemical-thinningpractices give quite unpredictable results. This inconsistency is atleast partly caused by weather factors, such as temperature and airhumidity, but tree factors are also involved. To solve this problem,climate-room and multi-site trials are proposed, together with anintergrated approach in elucidating background mechanisms and thedevelopment of new fruit thinning compounds.

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Wertheim, S. Developments in the chemical thinning of apple and pear. Plant Growth Regulation 31, 85–100 (2000). https://doi.org/10.1023/A:1006383504133

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