SCREENING MAIZE FOR TOLERANCE TO STRIGA-HERMONTHICA

Striga hermonthica is a widespread parasitic weed in Africa, causing severe damages to the major cereal crops: millet, sorghum and maize. Considering the subsistence nature of farming in Africa, the development of resistant or tolerant varieties is the most promising cost-effective approach to overcoming the weed problem. A simple, inexpensive and sufficiently uniform infestation technique has been developed by the research department of AgSeeds Ltd., Zaria, Nigeria, which is based on mulching a field with mature Striga plants collected in neigbbouring farmers' sorghum fields. With this method, rapid progress was achieved in the development of experimental maize hybrids with high levels of tolerance to S. hermonthica and good yield potential. Among 34 lines with improved tolerance, two (nos. 74 and 785) showed particularly high levels of tolerance. The hybrid between these two lines had a significantly higher yield (47.6%) under Striga infestation than the tolerant check 8322-13 developed by IITA.