Distribution and host range of some Cuscuta strains in the Near and Middle East.
Cuscuta incidence on sugar-beet in the Near and Middle East is widely spread. In field studies in Turkey, Syria, Lebanon, Iraq and Iran, 12.5% of the fields examined were infested. Syria (20%) and Iraq (26%) were particularly badly affected. In some areas, Cuscuta was very harmful. The 31 Cuscuta samples from 9 different hosts were identified as C. planiflora. Their host ranges differed. They all attacked sugar-beet. Those from sugar-beet parasitized 4 other hosts (cucumber, lucerne, pepper and tomato). However, strains from Solanum [S. melongena (aubergine) and S. nigrum] and onion did not parasitize cucumber or tomato. Cotton, okra and sesame were not successfully parasitized, though some development of Cuscuta on these plants was evident. Tobacco and beans (Phaseolus vulgaris) remained completely unaffected. Crop rotation and the control of potential host weeds (Alhagi maurorum, Centaurea sp. and Solanum nigrum) are suggested to help combat Cuscuta.