Damage potential of the phytophagous Eriophyidae and Tetranychidae mites (Acari; Tetrapodili, Prostigmata) in grapevine
1991
Hluchy, M. | Pospisil, Z. (Ustredni Kontrolni a Zkusebni Ustav Zemedelsky, Brno (CSFR))
The relationship between population densities of Calepitrimerus vitis, Colomerus vitis and Tetranychus urticae, grape weight and sugar content have been studied during three-year-long trials. In case of Calepitrimerus vitis, the influence of its population density on the leaf area, the length of the spring shoots and number of grapes in the following year have been studied as well. The significant relationship between population densities of both Calepitrimerus vitis and T. urticae at the late summer and the grape weight has been found out. The sugar content of the grapes has been markedly less influenced by mite infestation. The negative effects of the species Colomerus vitis on the grape weight has not been confirmed. The significant relationship for the control of protection measures has been worked out in the forms of nomograms. We suggest that 280 Calepitrimerus vitis per leaf and three mobile stages T. urticae per leaf are the economic injury levels in late summer for Czechoslovak conditions.
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