In the paper, we investigate the relationship between the walnut fruit quality and the leaf-to-fruit ratio (LFR). The LFR had a significant effect on the physical quality of walnuts (P < 0.05), and the fruit volume, fruit fresh weight, fruit dry weight, nut dry weight and kernel dry weight increased with an increasing LFR. However, the LFR had no significant effect on the crude protein and crude fat kernel contents (P > 0.05). The number of cells per unit area and the cross-sectional area of the green husk cells with 5L : 1F were significantly higher than those with 1L : 3F and 2L : 3F (P < 0.05). The number of cells per unit area of the kernel with 1L : 3F and 2L : 3F was significantly higher than that with the other LFRs (P < 0.05). There was no significant difference in the NDW between the natural and girdled fruit-bearing shoots with 2L : 1F (P > 0.05). We concluded that the high carbohydrate availability with the high LFR augmented the fruit size by increasing the number of cells in the green husk and kernels. There was no change in the crude protein and crude fat contents in the kernels, possibly due to the proportion of the sugar to the fat distribution not affected by the LFR. Two leaves with good light were necessary to ensure the normal growth and development of one walnut fruit on girdled fruit-bearing shoots.
Almanza-Merchán P.J., Fischer G., Serrano-Cely P.A., Balaguera-López H.E., Galvis J.A. (2011): The effects of leaf removal and cluster thinning on yield and quality of grapes (Vitis vinifera L., Riesling × Silvaner) in Corrales, Boyacá (Colombia). Agronomía Colombiana, 29: 35–42.
Baïram E., leMorvan C., Delaire M., Buck-Sorlin G. (2019): Fruit and leaf response to different source–sink ratios in apple, at the scale of the fruit-bearing branch. Frontiers in Plant Science, 10: 1039. https://doi.org/10.3389/fpls.2019.01039
Choi S.T., Park D.S., Hong K.P. (2011): Status of nitrogenous and carbohydrate compounds as affected by nitrogen fertigation rates in young persimmon trees. Scientia Horticulturae, 130: 354–356. https://doi.org/10.1016/j.scienta.2011.05.035
Du B., Li G.L., Zhou W.J., Liu B., Huang Y. (2011): Influence of different leaves/fruit ratio on fruit quality and nutrient content of Kiett mango. Guangdong Agricultural Sciences, 24: 29–31.
Famiani F., Antognozzi E., Boco M., Tombesi A., Battistelli A., Moscatello S., Spaccino L. (1997): Effects of altered source-sink relationship on fruit development and quality in Actinidia deliciosa. Acta Horticulturae (ISHS), 76: 355–360. https://doi.org/10.17660/ActaHortic.1997.444.55
Fang J.B., Zheng F., Chen J.Y. (2001): Effects of source-sink relationship on the photosynthetic intensity of kiwifruit leaves. In: Proceedings of the 9th Annual Aeminar Chinese Horticultural ociety. Beijing: China Press of Science and Technology: 75–80.
Fischer G., Almanza-Merchán P.J., Ramírez F. (2012): Source-sink relationships in fruit species. A review. Revista Colombiana de Ciencias Hortícolas, 6: 238–253. https://doi.org/10.17584/rcch.2012v6i2.1980
Hernandez-Santana V., Pérez-Arcoiza A., Gomez-Jimenez M.C., Diaz-Espejo A. (2021): Disentangling the link between leaf photosynthesis and turgor on fruit growth. The Plant Journal, 107: 1788–1801. https://doi.org/10.1111/tpj.15418
Heuvelink E. (2015): Dry matter partitioning in tomato: validation of a dynamic simulation model. Annals of Botany, 77: 71–80.
Higashi K., Hosoya K., Ezura H. (1999): Histological analysis of fruit development between two melons (Cucumis melo L. reticulatus). Journal of Experimental Botany, 50: 1593–1597. https://doi.org/10.1093/jxb/50.339.1593
Kubo T., Hohjoy I., Hirat S. (2001): Sucrose accumulation and its related enzyme activities in the juice sacs of Satsuma mandarin fruit from trees with different crop loads. Scientia Horticulturae, 91: 215–225. https://doi.org/10.1016/S0304-4238(01)00262-X
Léchaudel M., Jannoyer M., Génardy M. (2004): Effects of the leaf: fruit ratio on growth and partitioning of water and dry matter in mango fruit. Acta Horticulturae (ISHS), 645: 429–433. https://doi.org/10.17660/ActaHortic.2004.645.54
Marquard R.D. (1987): Influence of leaf to fruit ratio on nut quality, shoot carbohydrates, and photosynthesis of pecan. HortScience, 22: 256–257.
Nasrallah M.E. (1989): The genetics of self-incompatibility reactions in Brassica and effects of suprressor genes. In: Lord E., Bernier G. (eds): Plant Reproduction: From Floral Induction to Pollination. Rockville, American Society of Plant Pyhsiologists Symposioum Series: 146–155.
Peng L.L., Jiang W.B., Han J. (2012): Effects of source-sink relationship change on yield and quality in fruit tree. Nonwood Forest Research, 30: 134–140.
Sala R.G., Andrade F.H., Westgate M.E. (2007): Maize kernel moisture at physiological maturity as affected by the source–sink relationship during grain filling. Crop Science, 47: 711–716. https://doi.org/10.2135/cropsci2006.06.0381
Smith M.R., Rao I.M., Merchant A. (2018): Source-sink relationships in crop plants and their influence on yield development and nutritional quality. Frontiers in Plant Science, 9: 1889. https://doi.org/10.3389/fpls.2018.01889
Walker A.J., Ho L.C. (1997): Carbon translocation in the tomato: carbon import and fruit growth. Annals of Botany, 41: 813–823.
Willey R.L. (1971): Microtechnique: A laboratory guide. Memillan Publishing Co., Inc., New York, Memillan Publishing Co., Inc.: 99.
Xu M. (2015): Effects of different leaf-fruit ratio on fruit quality and leaf characteristics in ‘Xueqing’pear. [MS thesis], Hebei Agricultural University, China, 37–38.
Yuan J., Shi B., Wu Z.L., Tan X.F. (2015): Response of fruit quality and leaf photosynthesis to different sink-source relationships in Camellia oleifera. Plant Physiology Journal, 51: 1287–1292.
Zamski E., Schaffer A.A. (1996): Photoassimilate Distribution in Plants and Crops: Source-Sink Relation-ships. New York, Marcel Dekker Inc: 851–881.
Zhang Y.J., Zhang G.T., Wang W.P., Zhu S.S., Zhu Y.Y., He X.H. (2016): Effect of different leaf number and different time to remove leaves on berry quality of Chardonnay at high altitude grapevine in Shangri-La. Northern Horticulture, 22: 30–35.