Plant Protection Institute, BG-2230 Kostinbrod, Bulgaria
MILANOVA, S., 2001. Some morphological and bioecological characteristics of Iva xanthifolia (Nutt). Bulg. J. Agric. Sci., 7: 141-146
Iva xanthifolia is established for the first time in Bulgaria in the region of Kostinbrod in 1996. Some important peculiarity of the morphological characteristics of Iva xanthifolia and its biology for the ecological conditions of Bulgaria were studied. The results showed the following: the number of seeds per plant varies from 35692 to 50364, maximum 105 000; the optimal soil depth requirements for emergence of seeds is 1-2 cm for the conditions of sandy loam soil and 1-3 cm for the chernozem smolnitsa; a seasonal change in the germination of buried seeds was established; with increasing the rate of N nutrition the plants produced significantly more fresh matter.