Effects of the whole vine versus single shoot-crop level on fruit growth in Vitis labruscana 'Concord'

The fruit growth response to the whole vine and single shoot crop level was studied in Vtis labruscana 'Concord' grown in the North- Eastern United States. In vines thinned to lower and higher yields (equivalent to 12 and 21 Mia ^-1), different number of clusters per shoot were retained after cluster thinning one week after set. Results showed that the seasonal accumulation of berry dry weight, fruit fresh weight, and the berry total soluble solids at harvest were only affected by the whole vine crop level. This suggests that under the conditions of this experiment shoots are not autonomous in terms of carbon partitioning to the fruit. Hence, crop level effects on fruit development can be considered and modelled on a whole vine basis.