Document Type : Research paper


1 Department of Horticultural Science, School of Agriculture, Shiraz University, Shiraz, Iran

2 Department of Horticulture Faculty of Agriculture Shiraz University Shiraz, Iran


Some cultivars of grapevine have very compact cluster which adversely affect its quality and marketability. ‘Yaghouti’ is a commercial early table grape cultivar that has very compact clusters. The present study was conducted to assess the effects of mechanical and chemical thinning as well as GA3 application on cluster morphology and berry size of grapevine cv. ‘Yaghouti’. Treatments were chemical thinning agents including: NAA (7.5 and 15 mg/L), Ethephon (75 and 150 mg/L), Sevin (750 and 1500 mg/L) and mechanical thinning by a comb (comb thinning), applied a week after fruit set and unthinned clusters as control with 3 replications, 10 days after thinning, clusters were immersed in GA3 solution at 60 mg/L. Results indicated that berry numbers were reduced in all thinning treatments. Length, width and weight of berries increased significantly when treated with hand or chemical thinning. GA3 alone and Sevin at 750 mg/L in combination with GA3 treatment improved yield and the quality of berries. Total phenolics compounds, TSS and berries colour were improved in all thinning treatments. In general, application of Sevin at 750 mg/L combined with GA3 and hand thinning along with GA3 are proposed to improve quality of grapevine berries.


AOAC Official Method. 2005. Total monomeric anthocyanin pigment content of fruit juices, beverages, natural colorants, and wines. pH Differential Method.37:1- 68.
2. Carreno J.A, Martinez L, Almelaand J, Fernandez-Lopez A. 1995. Proposal of an index for the objective evaluation of the colour of red table grapes. Food Research International. 28:373-377.
3. Creasy G.L, CreasyL.L. 2009. Grapes.CABI. 295p.
4. Davies P.J. 2004. Plant hormones and their role in plant growth and development. Kluwer Academic Pub. 681p.
5. Dennis F.G. 2000. The history of fruit thinning. Plant Growth Regulation. 31:1-16.
6. Frank B, JoseM, Cartagenaand R, Spaiers M. 2005. Response rabbiteye blueberries to
chemical thinning agents. Acta Horticulturae.880:160-166.
7. Gil G, Escobar R.1979. The use of gibberellic acid for regulating bunch compactness in vigorous arbours. Ciencia Investigation Agraria, 6:15-20.
8. Lavin A.A. 1982. Effect of gibberellic acid, bunch thinning and cane girdling on yields and some berry characters of grapevine CV. Moscatel Rosadal. Agric. Tecnic. 42:173-176.
9. Levent S. 2010. Effects of hand and chemical thinning on fruit size and quality of cultivars ‘Priana’ and ‘Beliana’ apricot (Prunus armeniaca). New Zealand J. Crop Hort. Sci. 32:331-335.
10. Looney N.E. 1981. Some growth regulator and cluster thinning effects on berry set and size, berry quality and annual productivity of De Chounae grapes. Vitis, 20: 22-35.
11. Looney N.E, Wood D.F. 1977. Some cluster thinning and gibberellic acid effects on fruit set, berry size, vine growth and yield of De Haunac grapes. Canadian Journal of Plant Science. 75: 653-659.
12. Makhija M, Chandra A, Yamadagni R. 1988. Note on physicochemical characters of grape berries in cultivar Perlette as influenced by foliar application of chemicals. Curr. Agric. 12:99-100.
13. Marini R.P. 2004. Combinations of ethephon and Accel for thinning Delicious apple trees. Journal of the American Society for Horticultural Science. 129:175-181.
14. Mawdsley P.F.W, Peterson J.C.D, Casassa L.F. 2018. Agronomical and Chemical Effects of the Timing of Cluster Thinning on Pinot Noir (Clone 115) Grapes and Wines. Fermentation, 4, 60; doi:10.3390/fermentation4030060.
15. Moon J.H, Terao J. 1998. Antioxidant activity of caffeic acid and dihydrocaffeic acid in lard and human low-density lipoprotein. Journal of Agricultural and Food Chemistry. 46:5062-5065.
16. Mustafa C, Hisil Y, Durmaz G. 2009. Classification of eight pomegranate juices based on antioxidant capacity measured by four methods. Journal of Agricultural and Food Chemistry.112:721–726.
17. Naito R, Yamamura H, Takashima K, Koba F. 1985. Effects of denapon and ethrel on thinning grapes. Scientia Horticulturae. 25:61-69.
18. Rahemi M, Ramezanian A. 2007. Potential of ethephon, NAA, NAD and urea for thinning
Cluster and Berry Characteristics of Grapevine … 385
pistachio fruitlets. Scientia Horticulturae . 111:160-163.
19. Roberto G.R, Fernando W, Borgesa S, Carlos Colombo R, Koyama R, Hussain I, Teodoro de Souza R. 2015. Berry-cluster thinning to prevent bunch compactness of ‘BRS Vitoria’, a new black seedless grape. Scientia Horticulturae.197: 297-303.
20. Roberto S.R, Mashima C.H, Colombo R.C, Assis A.M, Koyama R, Yamamoto L.Y, Shahab M, and Souza R.T. 2017. Berry-cluster thinning to reduce compactness of ‘Black Star’ table grapes. Ciência Rural. 47(4).
21. Robinson T, Lopez S.2010. Chemical thinning and summer PGRs for consistent return cropping of Honeycrisp apples. Acta Hort. 884:635-642.
22. Ryugo K. 1988. Fruit Culture, It, s Science and Art. John Willy and Sons. New York. U. S. A. 344p.
23. Salehi L, Eshghi S, Gharghani A. 2013. Antioxidant activity and its correlation with phenol and anthocyanin contents in some grape cultivars grown in Fars province. Isfahan University of Technology-Journal of Crop Production and Processing. 3:111-121.
24. Schupp J.R, AuxtBaughcr T, Miller S.S, Harsh R.M, Lesser K.M. 2008. Mechanical thinning of peach and apple trees reduces labour input and increases fruit size. HortTechnology,18:161-170.
25. Silva H.O. 2018. Alternatives to bunch thinning in yield control and its effects on quality of the grapes and wine composition in cv. Baga (Vitis vinifera L.). Tese de Doutoramento apresentada à Faculdade de Ciências da Universidade do Porto Ciências Agrárias.
26. Singh I.S. Schundawat B. 1980. Effect of crop
level and leaf area on growth and quality of Beauty Seedless grape. Annals of Arid Zone. 19: 293-296.
27. Son L. 2004. Effect of hand and chemical thinning on fruit size and quality of Priana and Beliana apricot cultivars. New Zealand Journal of Crop and Horticulture Science. 23:331-335.
28. Stoper M, Schlauer B, Trruk B.A. 2007a. Thinning Golden Delicious apples using single or combining application of ethephon, NAA or BA. Journal of Central European Agriculture. 8:141-146.
29. Stoper M., Tojnko S, Ambrozic B. 2007b. Fruit thinning of Gala apple trees using ethephon, NAA, BA and their combinations.Pomological. Croatica, 13:143-151.
30. Szot I. 2010. Flower and fruit thinning effects on the development and quality of Sampion apple fruits. Journal of Fruit and Ornamental Plant Research. 18(2):129-138.
31. Taleb R. 2010. Berry size of Thompson Seedless as influenced by the application of gibberllic acid and cane girdling. Pakistan J. Bot. 42(3):1755-1760.
32. Vego D.P, Knezovic Z. 2010. Fruit thinning of peach and nectarin. Acta Hort. 884:695-670.
33. Wertheim S.J. 2000. Developments in the chemical thinning of apple and pear. Plant Growth Regul.31: 85-100.
34. Wood D.F, Looney N.E. 1977. Some cluster thinning and gibberellic acid effects on juice and wine quality of DeChaunae grapes. Canadian Journal of Plant Science. 57: 643-646.
35. Wrolstad R.E. 1976. Color and pigment analyses in fruit products. In: Agriculture Station Bulletin. 624: Oregon State University.