A comparison of different fruit thinning agents in apple cultivar 'Golden Delicious'
The natural crop load of cultivar 'Golden Delicious' varies greatly from year to year, but is often too high under Belgian climatological conditions resulting in a high percentage of small fruits. Hence, thinning is necessary to obtain a good fruit size. In the trial discussed here the following chemical thinning agents were compared: Amid-Thin (60 g naphtyl acetamide or NAD ha-1 standard orchard), Ethephon 480 (120 g ethephon ha-1 standard orchard), 6-benzyladenine (6-BA) (150 g active ingredient or a.i. ha-1 standard orchard) and metamitron (330 g a.i. ha-1 standard orchard). All thinning agents except ethephon are registered in Belgium for fruit thinning. Only 6-BA and metamitron effectively thinned 'Golden Delicious' in 2016, while no clear thinning effect of NAD and ethephon was observed.
Verjans, W., Deckers, T., Vandermaesen, J., Bylemans, D. and Remy, S. (2018). A comparison of different fruit thinning agents in apple cultivar 'Golden Delicious'. Acta Hortic. 1221, 9-16
climatic conditions, daily radiation, fruit quality, photosynthesis inhibition, thinning efficacy