Skip to main navigation menu Skip to main content Skip to site footer
ASPHC Baner

ONLINE FIRST

Articles

Influence of several methods of flower and fruitlet thinning on the yield and quality of Gala Must apples

DOI: https://doi.org/10.24326/asphc.2025.5489
Submitted: January 21, 2025
Published: 11.06.2025

Abstract

Apple trees of the Gala Must, grafted onto the dwarfing M.9 rootstock, planted in 2014 at a spacing of 3.5×1.8 m, were subjected to flower and fruitlet thinning in 2022–2024. Seven thinning combinations were used: 1 – (M) Mechanical thinning of flowers at the stage when the petals had emerged in 2 or 3 flowers in the inflorescence, using the German BAUM device; 2 – (C) Chemical thinning of fruitlets with Globaryll 100 SL containing cytokinin; 3 – (H) Hand thinning of fruitlets after June drop; 4 – (M+C) Mechanical thinning of flowers with the BAUM device supplemented by chemical thinning of fruitlets as in pt. 2; 5 – (M+H) Mechanical thinning of flowers with the BAUM device supplemented by hand thinning of fruitlets after June drop; 6 – (C+H) Chemical thinning of fruitlets with Globaryll 100 SL supplemented by hand thinning after June drop; 7 – (Control) Trees in which neither flowers nor fruitlets were thinned out.
In most treatments, the thinning of flowers or fruitlets caused a significant decrease in fruit yield but improved fruit quality, compared with the control. The thinning treatments increased the weight and size of apples, as well as their soluble solids content. Most apples were of a favourable marketable size in the range of 7.0–7.5 cm. The combined thinning treatments (M+H, M+C, C+H) resulted in the production of too many overgrown apples, which are known to be more susceptible to bitter pit, which in turn may reduce their storage life. Most of the thinning treatments resulted in a higher soluble solids content in the fruit without a significant effect on their firmness.

References

  1. Basak, A. (2000). Use of benzyladenine, endothall and ammonium thiosulfate for fruitlet thinning in some apple cultivars. Acta Hort., 517, 217–225. https://doi.org/10.17660/ActaHortic.2000.517.25
  2. Basak, A., Juraś, I., Wawrzyńczak,P., Blanke, M. (2013). Environmental – friendly thinning in apple by use of the ‘BAUM’ device, alone or combined with benzyladenine at reduced rate. Acta Hort., 998, 43–50. https://doi.org/10.17660/ActaHortic.2013.998.4
  3. Beber, M., Purgaj, B.D., Veberic, R. (2016). The influence of mechanical thinning on fruit quality and constant bearing of ‘Jonagold’ apples. Acta Hort., 1139, 513–517. https://doi.org/ 10.17660/ActaHortic.2016.1139.88
  4. Bertschinger, L.S., Stadler, W., Stadler, P., Weibel, F., Schumacher, R. (1998). New methods of environmentally safe regulation of flower and fruit set and of alternate bearing of the apple crop. Acta Hort., 466, 65–70. https://doi.org/10.17660/ActaHortic.1998.466.11
  5. Blanke, M. (2008). Perspectives of fruit research and apple orchard management in Germany in a changing climate. Acta Hort., 772, 441–446. https://doi.org/10.17660/ActaHortic.2008.772.75
  6. Buban, T. (2000). The use of benzyladenine in orchard fruit growing: a mini review. Plant Growth Regul., 32, 381–390. https://doi.org/10.1023/A:1010785604339
  7. Costa, G.D., Blanke, M., Widmer, A. (2013). Principles of thinning in fruit tree crops – needs and novelties. Acta Hort., 998, 17–26. https://doi.org/ 10.17660/ActaHortic.2013.998.1
  8. Damerow, L., Kunz, A., Blanke, M. (2007). Mechanische Fruchtbehangsregulierung. [Regulation of fruit set by mechanical flower thinning]. Erwerbs‐Obstbau, 49, 1–9. https://doi.org/10.1007/s10341-007-0029-9
  9. Dennis, F.G. (2000). The history of fruit thinning. Plant Growth Regul., 31, 1–16. https://doi.org/10.1023/A:1006330009160
  10. Dorigoni, A., Lezzer, P. (2007). Chemical thinning of apples with new compounds. Erwerbs-Obstbau, 49, 93–96. https://doi.org/10.1007/s10341-007-0038-8
  11. Dorigoni, A., Lezzer, P., Micheli, F., Dallabetta, N., Pasqualini, J. (2010). Diradare il melo a macchina: cosa sapere per farlo bene [Mechanical thinning of apple trees: what you need to know to do it right]. L’Inf. Agr., 66(22), 63–67.
  12. Embree, C.G., Myra, M.T.D., Nichols, D.S., Wright, A.H. (2007). Effect of blossom density and crop load on growth, fruit quality and return bloom in ‘Honeycrisp’ apple. HortScience, 42, 1622–1625. https://doi.org/10.21273/HORTSCI.42.7.1622
  13. Fallahi, E., Greene, D.W. (2010). The impact of blossom and postbloom thinners on fruit set and fruit quality in apples and stone fruits. Acta Hort., 884, 179–188. https://doi.org/10.17660/ActaHortic.2010.884.20
  14. Greene, D.S., Costa, G.D. (2013). Fruit thinning in pome- and stone-fruit: state of the art. Acta Hort., 998, 93–102. https://doi.org/10.17660/ActaHortic.2013.998.10
  15. Hampson, C., Bedford, K. (2011). Efficacy of blossom thinning treatments to reduce fruit set and increase fruit size of ‘Ambrosia’ and ‘Aurora Golden Gala’ apples. Can. J. Plant Sci., 91, 983–990. https://doi.org/10.1139/CJPS2011-070
  16. Hehnen, D., Hanrahan, I., Lewis, K., McFerson, J., Blanke, M. (2012). Mechanical flower thinning improves the fruit quality of apple and promotes consistent bearing. Sci. Hortic., 134, 241–244. https://doi.org/10.1016/j.scienta.2011.11.011
  17. Kon, T.M., Schupp, J.R., Winzeler, H.E., Marini, R.P. (2013). Influence of mechanical string thinning treatments on vegetative and reproductive tissues, fruit set, yield, and fruit quality of ‘Gala’ apple. HortScience, 48, 40–46. https://doi.org/10.21273/HORTSCI.48.1.40
  18. Kong, T., Damerow, L., Blanke, M. (2009). Influence on apple trees of selective mechanical thinning on stress-induced ethylene synthesis, yield, fruit quality (fruit firmness, sugar, acidity, colour) and taste. Erwerbs-Obstbau, 51, 39–53. https://doi.org/ 10.1007/s10341-009-0080-9
  19. Link, M., Blanke, M. (1998). Effect of thinning in a long-term trial with six apple cultivars on yield and fruit size. Acta Hort., 466, 59–64. https://doi.org/10.17660/ActaHortic.1998.466.10
  20. Looney, N.E. (1993). Improving fruit size, appearance, and other effects of fruit crop “quality” with plant bioregulating chemicals. Acta Hort., 329, 120–127. https://doi.org/10.17660/ActaHortic.1993.329.21
  21. Lordan, J., Alins, G., Àvila, G., Torres, E., Carbó, J., Bonany, J., Alegre, S. (2018). Screening of eco-friendly thinning agents and adjusting mechanical thinning on ‘Gala’, ‘Golden Delicious’ and ‘Fuji’ apple trees. Sci. Hortic., 239, 141–155. https://doi.org/10.1016/j.scienta.2018.05.027
  22. Martin-Gorriz, B., Torregrosa, A., García Brunton, J. (2012). Post-bloom mechanical thinning for can peaches using a hand-held electrical device. Sci. Hortic., 144, 179–186. https://doi.org/10.1016/j.scienta.2012.07.003
  23. McArtney, S.J., Obermiller, J.D. (2010). Evaluation of a model to predict the response of ‘Gala’ apples to chemical thinners. Acta Hort., 884, 581–586. https://doi.org/10.17660/ActaHortic.2010.884.75
  24. McArtney, S.J., Palmer, J.W., Adams, H.M. (1996). Crop loading studies with ‘Royal Gala’ and ‘Braeburn’ apples: effect of time and level of hand thinning. New Zealand J. Crop Hort. Sci., 24, 401–407. https://doi.org/10.1080/01140671.1996.9513977
  25. McClure, K.A., Cline, J.A. (2015). Mechanical blossom thinning of apples and influence on yield, fruit quality and spur leaf area. Can. J. Plant Sci., 95, 887–896. https://doi.org/10.4141/cjps-2014-421
  26. Menzies, A.R. (1980). Timing, selectivity and varietal response to mechanical thinning of apples and pears. J. Hortic. Sci., 55, 127–131. https://doi.org/10.1080/00221589.1980.11514913
  27. Misimović, M., Vukojević, D., Zavisić, N., Simić, J. (2012). Thinning of apple fruits with foliar fertilizers Goëmar BM 86 E and Goëmar Folical. Agric. Conspec. Sci., 77(1), 15–19.
  28. Ngugi, H.K., Schupp, J.R. (2009). Evaluation of the risk of spreading fire blight in apple orchards with a mechanical string blossom thinner. HortScience, 44, 862–865. https://doi.org/10.21273/HORTSCI.44.3.862
  29. Peifer, L., Ottnad, S., Kunz, A., Damerow, L., Blanke, M. (2018). Effect of non-chemical crop load regulation on apple fruit quality, assessed by the DA-meter. Sci. Hortic., 233, 526–531. https://doi.org/10.1016/j.scienta.2017.11.011
  30. Pflanz, M., Gebbers, R., Zude-Sasse, M. (2016). Influence of tree-adapted flower thinning on apple yield and fruit quality considering cultivars with different predisposition in fructification. Acta Hort., 1130, 605–612. https://doi.org/10.17660/ActaHortic.2016.1130.90
  31. Robinson, T.L., Lakso, A.N. (2011). Predicting chemical thinner response with a carbohydrate model. Acta Hort., 903, 743–750. https://doi.org/10.17660/ActaHortic.2011.903.103
  32. Schupp, J.R., Kon, T.M. (2014). Mechanical blossom thinning of ‘GoldRush’/M.9 apple trees with two string types and two timings. J. Amer. Pom. Soc., 68(1), 24–32.
  33. Schupp, J.R., Baugher, T.A., Miller, S.S., Harsh, R.M., Lesser, K.M. (2008). Mechanical thinning of peach and apple trees reduces labor input and increases fruit size. HortTechnology, 18, 660–670. https://doi.org/10.21273/HORTTECH.18.4.660
  34. Seehuber, C., Damerow, L., Kunz, A., Blanke, M. (2014). Selective mechanical thinning for crop load management of fruit trees. Acta Hort., 1058, 405–410. https://doi.org/10.17660/ActaHortic.2014.1058.49
  35. Solomakhin, A.A., Blanke, M. (2010). Mechanical flower thinning improves the fruit quality of apples. J. Sci. Food Agric., 90, 735–741. https://doi.org/10.1002/jsfa.3875
  36. Solomakhin, A.A., Trunov, Y.V., Blanke, M., Noga, G. (2012). Crop load regulation of fruit trees by means of a mechanical flower thinning device. Acta Hort., 932, 471–476. https://doi.org/10.17660/ActaHortic.2012.932.68
  37. Strijker, D. (2005). Marginal lands in Europe-causes of decline. Basic Appl. Ecol., 6, 99–106. https://doi.org/10.1016/j.baae.2005.01.001
  38. Theron, K.I., Steenkamp, H., Lotze, G.F.A., Steyn, W.J. (2016). The efficacy of chemical and mechanical thinning strategies for ‘African Rose (TM)’ Japanese plum (Prunus salacina Lindl.). Acta Hort., 1138, 61–67. https://doi.org/10.17660/ActaHortic.2016.1138.8
  39. Tromp, J. (2000). Flower-bud formation in pome fruits as affected by fruit thinning. Plant Growth Regul., 31, 27–34. https://doi.org/10.1023/A:1006342328724
  40. Untiedt, R., Blanke, M. (2001). Effects of fruit thinning agents on apple tree canopy photosynthesis and dark respiration. Plant Growth Regul., 35, 1–9. https://doi.org/10.1023/A:1013894901621
  41. Veal, D.U., Damerow, L., Blanke, M. (2011). Selective mechanical thinning to regulate fruit set, improve quality and overcome alternate bearing in fruit crops. Acta Hort., 903, 775–781. https://doi.org/10.17660/ActaHortic.2011.903.107
  42. Wertheim, S.J. (2000). Developments in the chemical thinning of apple and pear. Plant Growth Regul., 31, 85–100. https://doi.org/10.1023/A:1006383504133
  43. Whiting, M.D., Ophardt, D. (2005). Comparing novel sweet cherry crop load management strategies. HortScience, 40, 1271–1275. https://doi.org/10.21273/HORTSCI.40.5.1271
  44. Win, N.M., Song, Y.Y., Nam, J.C., Yoo, J., Kang, I.K., Cho, Y.S., Yang, S.J., Park, J. (2023). Influence of mechanical flower thinning on fruit set and quality of ‘Arisoo’ and ‘Fuji’ apples. Int. J. Plant Biol., 14(2), 503–511. https://doi.org/10.3390/ijpb14020039
  45. Wójcik, P., Gubbuk, H., Akgül, H., Gunes, E., Ucgun, K., Koçal, H., Küçükyumuk, C. (2009). Effect of autumn calcium sprays at a high rate on ‘Granny Smith’ apple quality and storability. J. Plant Nutr., 33(1), 46–56. https://doi.org/10.1080/01904160903391073

Downloads

Download data is not yet available.

Similar Articles

<< < 3 4 5 6 7 8 9 10 11 12 > >> 

You may also start an advanced similarity search for this article.