Influence of some factors on colonization of twospotted spider mite (Tetranychus urticae Koch) on chrysanthemum Chrysanthemum 'Veria Dark' and 'Cassablanca White'

Abstract

The research on factors (air temperature, relative air humidity, technology of irrigation, density of non-glandular trichomes) which influence the colonisation of twospotted spider mite (Tetranychus urticae Koch) on Chrysanthemum 'Veria Dark' and 'Cassablanca White' was carried out in 2003 and 2004 in greenhouses and in laboratories of the Biotechnical Faculty (Ljubljana). Both chrysanthemums were grown from seedlings with root clods. The technology of chrysanthemum growing was carried out according to professional recommendations and our own observations. Drop irrigation and flood irrigation were used. We found out that colonization of twospotted spider mite depends on the type of colonization and the density of leaf non-glandular trichomes. In both varieties of chrysanthemum, colonization and procreation of twospotted spider mite are influenced by air temperature and relative atmospheric humidity. Excess of water in the substrate have negative effect on chrysanthemums condition.