By using image analysis, we could non-destructively estimate leaf area index (LAI) of canopies of photosynthesizing shoots for 'Asami Red' roses trained to "arching" system by several methods when the LAI was less than 4.0. We also studied the relationship between LAI and shoot productivity and found that an LAI of 3.0 to be optimum for the production of "arching" rose plants. Harvesting flowering shoots leaving two five-leaflet leaven effectively increased their number and cumulative fresh weights, compared with harvesting, shoots at their point of outgrowth. The necessity of maximizing flowering shoot outgrowth m a sink was discussed.