The aim of this trial was to compare the thinning efficiency ofchemicalssprayed at different volumes, in apple (Malus domestica Borkh), cultivar Gala. Naphthaleneacetic acid (NAA) (15 g/ha of a.i.) and carbaryl (1naphthylNmethylcarbamate) (1,000 g/ha of a.i.) were used in spray solutions at 16, 300, 430, 950, 1,300 and 1,900 L/ha maintaining the dose of each product per hectare. NAA was sprayed at five days after full bloom (DAFB) and carbaryl at 15 DAFB. The volume did not play a major role on the efficiency of the treatments on fruit thinning: the different spray volumes showed similar thinning efficiency on 'Gala' apple. Except at 430 L/ha, chemical thinners sprayed at different volumes gave fruit weight and percentage of fruits >66 mm greater than the control, but did not differ among them.
Malus domestica; apples; NAA; carbaryl; plant growth substances
