The study of biological control of misteletoes.

The Semi Parasitic plants mistletoes are one of the most important pathogenic agents in the forest societies of Iran, Particularly in the fars and kohgiloyeh and BoyerAhmad province. For determination of the species of mistletoes and identification of their hosts. were carried out in numerous excursions through the collection of the host samples which were parasited by the mistletoes in different seasons, during 1375-6 to this parasite three representative stations with different cover types were sellected. The Saverse Mountain station with 6246 ha area, represents the Amygdalus spp and Cratagus spp association, the Tangsorkh mountain station, with 4500 ha extent, represents the pyrus spp; and the kohva mountain stations, with 4904 ha expause represent, Amygdalus spp and Acer spp associations. Samplinges were performed in 250x 750 m plots one the each station. Elevation exposure volume of crown trees and slope of each plot were determined. the infected healthy bushes were counted truits of 60 branches of the infected and healthy bushes were also collected and weighted. The results of this study showed that: 1) Nine scrb species (Amygdalus lyeioides spahc. pyrus glarba spach. two species cratagus spp, A. scoparia spach, Acer monspessulanum spach Catoneater persica spach, Amygdalus eburnea spach and cerasus microcarpa spach were found to be infected with mistletoe These plants inhabit all exposures above the 1400m MSL. 2) Forest trees inhabit in southeastern, southern, and southwestern exposures were more parasited than the bushes on other exposures. proference of birds wich carry the parasite for the warmer sites maybe one reason for the prevalence of mistletoes on those warmer exposures. 3) The species of mistletoe in kohgiloyeh and Boyrahmad province,s forest societies was indentifieted Loranthus grewingkii spach (LOranthacea). This parasite wich bars red and green fruits. 4) Another specimen of mistletoe which bears yellow fruits maybe a variety of L. gewingkii Distribution, the host rage and the extent of parasitism of this kind is less than those of the red- fruited species. 5) The weights of the fruits from the healty plants differend significantly from those of the infected bushes. 6) Those portions of the branches located above the infection center were usually dead. There were pravalence of difigured and dead trees in the severly infacted stands. 7) One Jenus of grass hoper (Melanoplus sp) eaten the leaf of present Mistletoes. 8) A few of fungi in Deutromyletes and ascomycetes group does infected of mistletoes, that probably be used for biological control.