نوع مقاله : مقاله پژوهشی
نویسنده
دانشیار، پژوهشکده میوه های معتدله و سردسیری، موسسه تحقیقات علوم باغبانی، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران.
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسنده [English]
An increase in the temperature and frequent droughts are consequences of the climate change. Using different methods of producing horticultural products in protected ways, such as shading net, is one approach to mitigate the impact of the changing climate. The present study was carried out to determine the effect of shading net on growth and fruit yield and quality of four grapevine (Vitis vinifera) cultivars in the Takestan grapevine research station in 2022. For this purpose, vegetative and reproductive characteristics of four grapevine cultivars (Sahebi, Red Sultana, Red Asgari and Mish Pestan) were evaluated under and outside of green shading net with shade coefficient of 50% as factorial arrangements in randomized complete block design with three replications. Significant increase of internode length under the shading net were recorded. Green shading net significantly increased the titratable acid (80.6%) and the pH of the fruit juice (73.2%), the length and width, and the weight of berry (21.8%, 44.11%, and 41.7%, respectively), cluster length, diameter and weight (51.6%, 49%, and 30.8%, respectively), and fruit yield per vine (65%). However, green shading net caused significant decrease in total soluble solids (17.7%). In all grape cultivars, the total soluble solids under the green shading net was lower than outside the green shading net, and the highest total soluble solids (26 Brix units) belonged to cv. Red Sultana outside of the shading net. The titratable acidity (TA) level of fruit juice under shading net was higher than outside the shading net in all grape cultivars. The highest TA level (8.5g l-1) was observed in cv. Mish Pestan under green shading net. The dimensions of berries under the shading net were greater than outside in all studied grape cultivars. The results showed that the fruit yield and its components increased under green shading net, but fruit ripening prolonged. Therefore, for table grape production, it is necessary to collect the shading net in fruit color changing period to prevent late ripening.
Keywords: Grape, vine, fruit yield, table grape, climate change.
Introduction
Due to changing climate, the yield and the quality of agricultural products including grapevine are significantly affected. The intensity of sunlight and high temperature are especially important because of their effects on phenological stages, fruit yield, flower and berry drop, berry weight, and on the production and accumulation of primary and secondary compounds. Using Shading nets have been suggested in viticulture as an adaptation and protection approach to mitigate the effect of high temperatures (global warming) and decrease evapotranspiration (Naulleau et al., 2021). The present study was carried out to determine the effect of the green shading net on growth, fruit yield and its components and quality of four grapevine (Vitis vinifera) cultivars in the Takestan grapevine research station, Takestan, Iran.
Materials and Methods
Four grapevine cultivars (Sahebi, Red Sultana, Red Asgari and Mish Pestan) were evaluated under and outside of green shading net with shade coefficient of 50% as factorial arrangements in randomized complete block design with three replications and three vines in each plot. Cluster dimensions and weight, clusters number vine-1, dimensions and weight of berry, total soluble solids (TSS), pH and titratable acidity (TA) of fruit juice, fruit yield vine-1 and internode length were measured and recorded. SPSS Ver. 26 software was used to test the data normality, analysis of variance, and means comparison by Tukey's test at the 5% probability level. Factor analysis was performed based on principal component analysis and varimax rotation, as well as drawing graphs, using XLSTAT 2019 add-in under Excel software.
Results and Discussion
Using green shading net significantly increased (66.2%) the internodes length. Green shading net significantly increased TA (80.6%) and pH of fruit juice (73.2%), but significantly decreased TSS (17.7%). The highest amount of TSS (26 Brix units) was obtained in cv.Red Sultana outside of the shading net and the lowest (17.9 Brix units) obtained in cv. Sahebi under the shading net. The highest amount of TA (8.5 g l-1) was observed in cv. Mish Pestan under the green shading net and the lowest (1.3 g l-1) in this cultivar in the outside of shading net.
Serat and Kulkarni (2015) reported that the maximum TSS, total sugar, reducing sugars, non-reducing sugars and the ratio of TSS to TA in grape variety Thomson Seedless in without shading net environment (compared to green shading net with shade factor of 30% and 50%) were obtained. The reduction of heat stress due to the use of shading net has delayed the activation of VvHsfA2 and VvGolS1 factors, which causes a decrease in TSS and delay in fruit ripening (Pillet et al., 2012).
Green shading net significantly increased the length, width, and weight of berries (21.8%, 44.11%, and 41.7%, respectively), cluster length, diameter, and weight (51.6%, 49%, and 30.8%, respectively) and vine yield (65%). The highest berry length (2.48 cm) was obtained in cv. Sahebi under the green shading net and the lowest (1.07 cm) was obtained in cv. Red Sultana outside of the shading net. The highest berry weight (4.25 g) was recorded in cv. Sahebir under the green shading net and the lowest (0.77 g) was recorded in cv. Red Sultana outside of the shading net. Rasoli et al. (2022) reported that white and green shading nets, with shading factor of 30%, increased the cluster weight by 107.2 and 141.8%, respectively.
The results of this research showed that using green shading net increased fruit yield and its components, and prolonged fruit ripening. Therefore, for table grape production, it is necessary to collect the shading net in color changing period to prevent late ripening.
References
Naulleau, A., Gary, C., Prevot, L. and Hossard, L. 2021. Evaluating strategies for adaptation to climate change in grapevine production-A systematic review. Frontiers in Plant Science, 11, pp.2154-2159. DOI: 10.3389/fpls.2020.607859
Pillet, J., Egert, A., Pieri, P., Lecourieux, F., Kappel, C., Charon, J., Gomès, E., Keller, F., Delrot, S. and Lecourieux, D. 2012. VvGOLS1 and VvHsfA2 are involved in the heat stress responses in grapevine berries. Plant Cell Physiology, 53, pp.1776–1792. DOI: 10.1093/pcp/pcs121
Rasoli, V., Nejatian, A.M. and Salahshorian, R. 2022. The effect of shading net on the quantitative and qualitative yield of Red Bidaneh grapes in the vineyard area. Journal of grape extension, 1(4), pp.29-34 (in Persian)
Serat, B. and Kulkarni, S.S. 2015. Effect of shade net on yield and quality of grapes cv. Thompson Seedless. International Journal of Science and Research, 4(5), pp.1841-1845.
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