Striga hermonthica reduces cereal yields in large areas of sub-Saharan Africa. Recent research has shown that transplanting maize seedlings that are more than 15 d old reduced Striga emergence and improved crop yields. Field experiments were conducted in 1998 and 1999 to determine whether maize varieties with different maturity periods and susceptibility to Striga parasitism respond similarly to transplanting. There was a considerable difference in Striga emergence between varieties in direct-seeded maize, but transplanting clearly reduced Striga emergence for all varieties. Transplanting of maize in plastic tubes gave the best Striga control until 8 wk after transplanting, whereas transplants from nurseries provided better season-long control. Transplanting improved grain yields 50 to 100% compared with direct seeding for three of the four varieties tested. Only the early-maturing variety ‘Morogoro’ had lower yields with transplanting than with direct seeding, indicating that transplanting caused more stress on the plants than was alleviated by the lower Striga infestation. The two varieties (‘Pioneer 3251’ and ‘H622’) most susceptible to Striga parasitism profited the most from transplanting, and the concomitant reduction in Striga induced stresses. Increases in productivity because of transplanting were associated with increases in biomass or harvest index. Transplanting of different maize varieties under rain-fed conditions has proven to be a biologically efficient method to improve maize yield and reduce Striga infestation within one season.
Nomenclature: Striga hermonthica (Del.) Benth; maize (corn), Zea mays L.