Response of Farmer Preferred Maize (Zea Mays L.) Varieties Screened Against Striga Hermonthica (Del.) Benth, Western Kenya

Abstract

Striga (Witch weed), root parasitic weed, causes substantial crop loses in sub-Saharan Africa (SSA). All cultivated cereal crops including maize, millet, sorghum and upland rice are parasitized by one or more species of Striga. The use of resistant crop varieties as part of the integrated pest management (IPM) strategy is the cheapest, most affordable, environmentally friendly, economical and suitable control measure. This study sought to determine the level of resistance to Striga hermonthica possessed by farmer preferred maize varieties grown in western Kenya. Screening strategies involved the artificial germination of Striga seeds with maize root exudates in controlled laboratory setups. Maize roots were also infected with pre-germinated Striga in root observation systems known as rhizotrons. This study determined the pre-attachment resistance response of farmer preferred maize varieties in addition to determining the post-attachment resistance response of farmer preferred maize varieties. Sixteen farmer preferred maize varieties and 3 Striga tolerant varieties from Maseno University breeding program were screened. Results indicated that: i) according to Tukey‘s Honest significant Difference test (p ≤ 0.05), maize varieties greatly varied in their ability to resist Striga infection. ii) H614D, DK8031, H629 and EH14A showed low Striga germination frequencies (< 40%), iii) H629, H614D and EH14A had the lowest mean count (< 75), mean length (< 4 mm) and mean biomass (< 25 mg). From the experiments, three farmer preferred maize varieties (EH14A, H629 and H614D) had significantly high resistance to the parasite. They experienced low Striga germination frequencies and low counts, length and biomass of attached Striga. These findings indicated that some western Kenya farmer preferred maize varieties harbor pre-attachment and post attachment resistance to Striga. These varieties should be incorporated into Striga breeding programs for the development of durable resistance. This would significantly increase the efficiency of integrated Striga management strategies in western Kenya.