Influence of Non-Host Crop Rotation on the Reaction of Cereal Host Crop Genotypes to Striga hermonthica of Different Ecotypes

Trial was conducted in the screen house of Niger State College of Agriculture, Mokwa (09° 18¹N; 05° 04¹E) in 2005 to evaluate the influence of rotation of trap crops (non-host) on the differential reaction of host crops genotypes to the parasitism of Striga hermonthica of different ecotypes (Location sources of Striga). A split-split arrangement in a randomized complete block design with three replications was adopted. The three varieties each of the host crops, maize (Acr.97 TZLComp.1-W, 9022–13 and 8338-1), rice (FARO 40, WAB 56–50 and FARO 45) and sorghum (SAMSORG 3, ICSV111 and SAMSORG 14) with and without Striga infection constituted the main plot treatments. The sub plot treatments were the three trap crop varieties each of groundnut (SAMNUT 10, SAMNUT 11 and SAMNUT 18), cowpea (SAMPEA 6, SAMPEA 7 and L25), soybean (TGx 1448-2E, TGx 1485-1D and SAMSOY 2) and cotton (SAMCOT 8, SAMCOT 9 and SAMCOT 10) while the sub-sub plot treatments consisted of the location sources of Striga (Abuja, Gboko, Zaria and Kano). The result obtained indicated that the genotypes of maize (9022–13 and Acr.97 TZL Comp.1-W), rice (FARO 40 and WAB 56–50) and sorghum (SAMSORG 3) exhibited various levels of resistance to Striga parasitism through support for lower infestation, exhibition of lower reaction syndrome and higher crop growth vigour as well as production of higher shoot dry matter than the respective susceptible varieties. The host crops exhibited differential reactions to different Striga ecotypes following the order Gboko > Abuja > Zaria = Kano. Host crops preceded by rotation of groundnut var. SAMNUT 11, soybean var. TGx 1448-2E, cowpea var. SAMPEA 7 and cotton var. SAMCOT 10 consistently had reduced Striga parasitism and increased growth vigour and productivity.