Abstract

During the 2013-2014 and 2014-2015 seasons, several thinning trials were carried out in commercial pear (Pyrus communis) orchards of ‘Forelle’ (4), ‘Coscia’ (4) and ‘Abate Fétel’ (1) in central Chile. The raw data of this research already published was used to build the response of fruit size and yield to increasing crop load for each cultivar and location. The response of fruit weight and yield efficiency (kg m-2 PARi) to crop load was done expressing standardized crop load as fruit ha-1 intercepting 70% of incident photosynthetically active radiation (PARi). The range of crop load varied from about 100,000 to 500,000 fruit ha-1 70% PARi for ‘Forelle’ and ‘Coscia’ and from 240,000 to 550,000 for ‘Abate Fétel’. Response of fruit weight and yield to crop load was described by linear equations in all cases. Value of the constant was inverse to the slope for fruit size for each cultivar, i.e., the larger the potential for fruit size the greater the reduction in fruit size due to the increase of crop load. The projected yield for ‘Forelle’ ranged from 18 to 82 t ha-1 while for ‘Coscia’ and ‘Abate Fétel’ varied from 12.8 to 54 t ha-1 and 51 to 95 t ha-1, respectively. Inversely, the fruit weight decreased from 204 to 171 g (16.2%) for ‘Forelle’, from 114 to 95 g (16.7%) for ‘Coscia’ and from 228 to 180 g (21.3%) for ‘Abate Fétel’.