IMPORTANCE AND USE OF CARBOHYDRATE RESERVES IN ABOVEGROUND STEM PARTSOF ROSE CV MOTREA

The effect of deshooting of flowering stems of rose cv. Motrea as comp ared with normal harvesting procedure was studied with respect to carb ohydrate storage and subsequent flower production after downwards prun ing of shoots. Growth analyses over two periods were conducted to calc ulate total biomass production and partitioning. Soluble sugars and st arch in samples of the stem taken at several heights in the plant were also analysed. In general, starch concentrations increased and sugar concentrations decreased from upper to lower stem parts. Deshooting in creased total non-structural carbohydrates, mainly caused by starch. T he stored carbohydrates were used during a subsequent flowering cycle. Total extra carbohydrate reserves due to the deshooting practice coul d explain the resulting increase in fresh-weight production. Biomass p roduction was not influenced by treatments over the experimental perio d but deshooting greatly reduced flower production and enhanced the we ight of discarded prunings. It is concluded that treatments primarily directed at redistribution of carbohydrates are probably of little use in improving the management of a rose crop.