Spatial variation in glasshouse rose flower production in relation to solar radiation

Abstract

Analysis of yield of rose flowers grown in glasshouses during the winter shows that a very significant difference exists in the total number of flowers along the east—west axis, with a centre minimum. The difference between east and centre was highest (almost 50 % difference in total number of flowers and 30 % difference in number of marketable flowers) in the first part of the season, when insolation was lowest. The variation in the north—south axis was less pronounced, but still highly significant (15 % during more than half of the season). The ratio of the number of marketable flowers to the total number of flowers varied only along the east—west axis, with the highest percentage at the centre. No significant differences in ratio were found in the north—south axis. The variations along the east—west axis and the north—south axis in number of flowers were related to variation in solar radiation within the glasshouses.