The effect of varying the berry number on Gordo Grape-vines with constant leaf area

Abstract

The leaf number of potted Muscat Gordo Blanco grape-vines was fixed but berry number per plant was varied. Root and berry dry weight, as well as rate of berry growth, were unaffected by treatment, dry weight per unit length of shoot and trunk and sugar leve! in trunks somewhat reduced, and stareh leve! in trunks most severely affected. These results are in contrast with those of an earlier experiment in which H was observed that a progressive reduction in retained leaf number affected root dry weíght most severely, followed by berry development, stareh and sugar levels of shoots and finally dry weight per unit length of shoots. Thus the effect of reducing leaf area (source size) was not the same as increasing crop load (sink size).