Importance and use of carbohydrate reserves in above-ground stem parts of rose cv. Motrea

Summary

The effect of deshooting of flowering stems of rose cv. Motrea as compared with normal harvesting procedure was studied with respect to carbohydrate storage and subsequent flower production after downwards pruning of shoots. Growth analyses over two periods were conducted to calculate total biomass production and partitioning. Soluble sugars and starch 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 increased total non-structural carbohydrates, mainly caused by starch. The stored carbohydrates were used during a subsequent flowering cycle. Total extra carbohydrate reserves due to the deshooting practice could explain the resulting increase in fresh-weight production. Biomass production was not influenced by treatments over the experimental period but deshooting greatly reduced flower production and enhanced the weight 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.