Cut flower yield of four greenhouse rose cultivars was primarily influenced by solar radiation, while atmospheric CO2, air temperature, and soil nutrient levels were of lesser importance. Cultivars responded differently to atmospheric CO2 level and soil fertilization method. Roses fertilized with 20-20-20 in solution produced equivalent or greater flower yields than roses fertilized with 10-10-10 in dry form. Roses grown in CO2 enriched atmospheres did not require additional soil fertilization.
Regression coefficients and yield prediction equations were determined using nine environmental parameters. Monthly yield predictions were generally reliable, but cropping cycles and cultural practices decreased accuracy.
Received for publication on April 28, 1970, Scientific Journal Series Paper No. 7204, Minnesota Agricultural Experiment Station.
Present address: Department of Horticulture and Forestry, Kansas State University, Manhattan, Kansas.