The marigold is a very ornamental plant that is commonly grown in the flower garden, and occasionally as a culinary herb. Marigolds had an important economic values, its cropping knew a continual increase in the last years thanks to its usage in a more and more large area in the pharmaceutic and cosmetic domain. Thrips tabaci are feeding drains underlying cells, leaving air-filled spaces which impart a silvery sheen and cause distortion during growth and reduction in photosynthetic capacity. In the West Plain of the country relative existed a few investigations about that pest attack on the marigolds crop, an important crop both from medical point of view and culinary point of view. The purpose of that work was to determine the correlation of pests attack degree and flowers diameter to 10 local population of Calendula officinalis L. from Arad district. In the thrips experiments, the results showed that flowers with bigger attack degree were smaller compared to flowers with smaller attack degree. This difference in flower diameter was due to deformations of the flowers and was more pronounced at a bigger density of common thrips. The flowers deformation and its decrease in diameter implied also the production increase, but the obtained quantity of flowers was lower. The results obtained through correlation between Thrips tabaci attack degree and morphological features of Calendula officinalis L. flowers permitted the identification of frequency and intensity of attack, and connection between them and density of the pest. Accordingly, tobacco trips produced great damages in Calendula officinalis L. crop depreciating from a qualitative point of view, the diminution and bending flowers diameter and qualitative speaking the production decreased. The present paper belongs to a big work which had like study “Resistance testing of some species of Calendula officinalis L. to Thysanoptera pest attack through different methods/techniques of analysis concerning the improvement of raw material quality”, that represented the theme of postdoctoral-dissertation.

marigold flowers; correlations; morphological features; tobacco thrips attack

Presentation: oral