Growth and Cut-Flower Productivity of Spray Rose as Affected by Shading Method during High Temperature Period

Abstract: This experiment was carried out to investigate the effects of shading materials (aluminum specific-shading screen and polypropylene non-woven fabric) and shading ratio (50% and 70%) on climatic changes, cut-flower quality, and yield of spra y rose cultivars for export during high temperature periods. The daily cumulative solar radiations were higher with the aluminum specific-shading screen, especially with 50% shading compared to polypropylene non-woven fabric. Air temperature and root zone temperature within rockwool media greatly decreased with the aluminum specific-shading screen, but relative air humidit y was not different among shading methods. Chlorophyll contents (SPAD values) were slightly higher with aluminum-specific shadin g screen than with polypropylene non-woven fabric, and were higher with 50% than with 70% aluminum specific-shading screen. Except for ‘Lovely Lydia’, marketable and exportable yields of all cultivars were higher with 50% than with 70% aluminum shading treatment I.n addition ,flower stalk length ,stem diameter n,umber of node and 7ea-leaflet a,nd floret number tended to be better with aluminum specific-shading screen. Flower stalk length was higher with 70% than with 50% aluminum shadin g treatment. Chromaticity of petals slightly increased, and vase life was 0.5-2.5 days longer for each cultivar with aluminum specific-shading screen than with polypropylene non-woven fabric.Additional key words: