Weight-Change Patterns in Cut and Intact Rose Shoots III. Flower Bud Development and Dry Matter Distribution in Flower and Foliage

Abstract

Summary To complement results obtained with non-destructive beta-ray gauging, we here report on fresh and dry weight change of rose buds unfolding into full bloom and in the senescing stage, and on results of a leaf-punch method to follow diurnal and long-term patterns of foliar weight in intact rose shoots and in water or sugar-treated cut ones. With total shoot weight known by direct weighing, foliar weight can be derived from leaf punching and total leaf area. From these data the evolution of corolla weight throughout anthesis can be reconstructed by calculating backwards from final weighing, and compared with a standard curve of intact-flower development. Foliar fresh weight showed diurnal fluctuation in unison with total shoot weight. By contrast, dry weight and percentage of dry matter peaked at the end of the light periods, with minima at the end of the dark. Long-term trends of all three parameters were in accordance with overall performance in the various treatments; in sucrose-treated shoots, percentage of foliar dry matter rose to very high final values. Dry matter distribution involved in fresh-weight patterns during vase-life is to be interpreted in relation to light intensity and total leaf area.