ROSE POWER PRODUCTION AS RELATED TO PLANT ARCHITECTURE AND CARBOHYDRATE CONTENT - EFFECT OF HARVESTING METHOD AND PLANT TYPE

The dependence between flowering cycles and woody stem parts of a rose crop was studied, with respect to plant architecture and carbohydrate content. Two harvesting methods (''control'' versus ''flush'') and tw o plant types (''control'' versus ''one stemmed'') were compared. Crop growth and partitioning of dry matter were studied as influenced by c rop management during 18 months of culture. For a full-productive year , Bush harvesting generally promoted bud break as compared with contin uous harvesting but at the same time, also due to lower light intercep tion, blind-shoot formation was enhanced and the individual Bower weig ht reduced. Numbers of basal shoots were hardly related to flower prod uction over a full cropping year. Flower production was much more sens itive to the number and diameter of branches at the height of cutting the Bowers. The treatments did not affect carbohydrate allocation in t he plant. Total carbohydrate storage was much too low to argue a clear role for the possible use of movement of carbohydrate reserves toward s new growth. Maximum starch concentration was found at the beginning of summer and gradually dropped to a minimum in December and then incr eased again to a spring maximum. A cold treatment did increase the tot al non-structural carbohydrate (TNC) concentration but no positive inf luence on new basal-shoot formation was observed. No starch gradient w as found in basal stem parts.