ABSTRACT.- Apple trees set many more fruit than desired, requiring a crop load adjustment to achieve acceptable fruit size in the season and an adequate return bloom, thus avoiding biennial bearing. Thus, the aim of this study was to evaluate the effect of different plant growth regulators as 6-benzyladenine (6-BA) and naphthaleneacetic acid (NAA) sprays and lime sulfur (LS) in apple thinning. Two trials were carried out in Uruguay on 2020/2021 growing season in 'Gala Baigent' and 'Rosy Glow' apples, respectively. Productive and quality parameters were evaluated. LS (3%) sprayed three times near the bloom and the different combination of 6-BA (100 mg L-1) + NAA (10 mg L-1) showed positive results reducing the number of thinned fruit and time of hand thinning compared to control trees in 'Gala Baigent' in 2020/2021 growing season. LS (3%) and the combination of 6-BA + NAA increased fruit weight of 'Gala Baigent' and did not significantly reduce yield on 2020/2021 growing season. For 'Rosy Glow' apples, LS sprayed three times reduced the number of thinned fruit and time of hand thinning compared to control. Fruit weight of 'Rosy Glow' apples was not increased by LS neither NAA at full bloom + 6-BA at petal fall, however, the combination of 6-BA (100 mg L-1) + NAA (10 mg L-1) at petal fall and the multiple sprays of NAA at full bloom plus the combination of 6-BA and NAA at petal fall, plus 6-BA + mineral oil at 15-18 mm increased fruit weight compared to untreated control trees. Collectively, our results are promising and indicate all the thinners used are potential tools on a chemical thinning program for apples to replace carbaryl. Furthermore, LS could be an option for growers in a thinning program, including for organic production. © 2023 International Society for Horticultural Science. All rights reserved.