CITTADINI, E.D.¹,²; BALUL, Y.J.¹, ³; ROMANO, G.S.¹; PUGH, A.B.¹
The objective of this work was to quantify the effects of intensity and time of thinning on the yield and fruit quality in sweet cherry trees. The experiment was performed in a commercial organic orchard trained as tatura in Chubut, Argentina. The treatments resulted from the combination of three levels of thinning intensity (elimination of 30%, 60% and 90% of the reproductive organs) and three thinning moments (1, 24 and 47 days after full bloom in “Lapins” and 7, 31 and 64 in “Sweetheart”), in addition to the controls for each cultivar. At the time of harvest we registered the yield and quality parameters such as firmness, soluble solids content, mean fruit weight and mean fruit diameter, and we evaluated the leaf area per tree. The yield significantly decreased only in relation to the thinning intensity. In “Lapins”, the mean fruit weight and the fruit diameter increased in relation to that variable. On the contrary, in “Sweetheart”, the thinning intensity did not have a significant effect, but we detected a reduction in mean fruit weight and fruit diameter as the fruit-thinning was delayed. In both cultivars the soluble solids content decreased as the fruit-thinning intensity increased. In “Lapins”, the firmness was not affected neither by the thinning intensity nor the time of thinning. Contrarily, in “Sweetheart” this variable decreased in relation the thinning moment. Within the ranges of the analyzed data, the yield increased lineally as a function of the fruit/leaf ratio, both in “Sweetheart” and in “Lapins”. In “Lapins”, the mean fruit weight decreased as a function of the fruit/leaf ratio, but no effects were detected in “Sweetheart”. However, in both cultivars fruit diameter reductions were detected in relation to the fruit/leaf ratio. In “Lapins”, the soluble solids content significantly decreased as a function of the fruit/leaf ratio, but in “Sweetheart” no effect of the crop load were detected on this variable. Analogously, in “Lapins” the firmness decreased as the fruit/leaf ratio increased, but this relationship was not detected in “Sweetheart”.
Keywords: mean fruit weight, Fruit diameter, Firmness, Soluble solids content, Fruit/leaf ratio.