The effect of hand vs. chemical fruit thinning with 1-naphthaleneacetamide (NAD) (40 ppm) and 1-naphthyl (N-) methylcarbamate (carbaryl) (1000 ppm) on apple fruit quality after 17 weeks in cold storage at 1 °C has been studied. Fruits from hand-thinned trees had lower weight loss (WL), firmness (F) and titratable acidity (TA), but soluble solids concentration (SSC) and SSC/TA were higher (P≤0.001). In chemically thinned fruits there was correlation between WL and SSC, WL and TA, SSC and TA, number of seeds per fruit and Hue angle. In hand-thinned fruit SSC/TA was correlated with Hue and WL. In both thinning methods SSC and WL were negatively correlated with Hue angle and positive correlation existed between WL and fruit weight. Further research should be made to find optimal thinning strategies that will have both good thinning effect and positive effect on fruit quality after storage.

Malus domestica Borkh.; thinning; carbaryl; 1-naphthaleneacetamide; fruit quality; storage

Published by University of Zagreb, Faculty of Agriculture, Zagreb, CROATIA
Sponsored by Ministry Science and Education of the Republic of Croatia