A Preliminary Survey of Dodder Cuscuta spp. on Ornamental Plants, and Economical Crops and its Biocontrol by Fungi

Abstract

A Preliminary survey was conducted for dodder Cuscuta spp., the most serious parasitic plant on ornamental plants, and some economical crops in some North West regions of Libyan Jamahiriya. This study was performed to investigate the dodder distribution, affected hosts, and the infested area with dodder. Field and green house survey started 1994 indicated that dodder increased its growth in early Spring till early Fall. The dodder has a wide host range, parasitize over45 species within 28 plant families. Some highly heavy infected seedlings were: Cestrum nacturnum, Myoporum serratum. Other heavily infected Acacia cyanaphylla, Calendula officinalis, Casuarina equisetifolia, Coleus hybrid, Geranium robertianum, Calendula officinalis, and some moderately infected seedlings: Ceratinia siliuqua, Eucalyptus sp., Hibiscus rosa-sinensis, Malavaviscus arborers, and Populus nigra, and those low infected were: Campsis radicans, Cuprssus sempervire, Pittosporum tobira and Thya oriinfected orintalis. and those very low infected Kalanchoe sp. Dodder highly affects other vegetable crops: Tomato, Eggplant, Pepper, Onion, Potatoes, and feed crops Alfalfa, and other wild plants. Ornamental plants showed differences in their infestation rate especially in heavily infested nurseries, where C. nacturnum. 60%. While 57% of Myoporum serratum had failed, 33% had yellowed dwarfed seedlings, ten percent were healthy compared nurseries, with Populus niger of the same age, only 10% had failed. However in the greenhouse, only 20% of vinca rosea was infested. Several fungi were isolated from diseased dodder parasitize on Acacia cyanaphlla, and Casuarina equisetifolia were Alternaria alternata. Dreschlera spp. and Curvularia sp. Also A. alternata, Aspergillus niger, and Penicillium spp were isolate from dodder seeds, some were pathogenic to dodder. Due to dodder damage, it is recommended to transplant healthy seedling with clean soil free of dodder seeds, biological control with fungi, and early burning of the infected plants.