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Striga (Witch weed) is well known partial root obligate parasitic weed and its highly successful pathogen of cereal crops in India. Striga is an attractive parasitic plant whose beautiful flowers belie its noxiousness. Most cultivated cereals including maize, millet, sorghum, sugarcane and rice are parasitized by at least one striga species, leading to enormous economic losses. Striga seeds are small (0.2 mm in length) and dust-like. Striga’s small seed size greatly enhances the parasite’s dispersal by wind, water and contaminated crop seeds. The small-sized seeds also adhere to people and animals, further aiding in seed spread and contamination of uninfected fields. However, a small striga seed size means that the endosperm can only support growth for three to seven days. Therefore, germination must be rapid and synchronized with host localization. Prodigious seed production, prolonged viability of the seeds and the subterranean nature of the early stages of parasitism make the control of the parasite by conventional methods difficult. Striga control measures like cultural, physical, chemical, biological, host plant resistance and genetically modified crops have been developed. Today there is no single control method that can effectively solve the problem. Integrated striga management based on destroying incipient populations, confining core infestations, minimizing reproduction of the parasite, devitalizing the parasite seed bank and reducing crop damage is recommended as the best method in control. KEYWORDS: Biology, control measures, haustoria development, life cycle, root parasitic |
