Maize (Zea mays L.) production in west and central Africa (WCA) is constrained by the parasitic weed Striga hermonthica (Del.) Benth and recurrent drought. Two early maize populations, TZE‐W Pop DT STR C0 (white) and TZE‐Y Pop DT STR C0 (yellow), developed from diverse genetic backgrounds, were subjected to three cycles of S1 recurrent selection under artificial Striga infestation. Inbreds and synthetic cultivars were developed from the different cycles of selection. The populations (C0), derived cultivars, and check cultivars were evaluated in 2002 and 2003 under Striga‐infested and Striga‐free environments in WCA. The objective was to assess the performance of the derived cultivars from the different cycles of selection. Under Striga infestation, ACR 94 TZE Comp5‐Y and ACR 94 TZE Comp5‐W, which were not from the selection program, were the highest‐yielding group (2158 and 2124 kg ha−1, respectively). The second group comprised six products of the selection program, with grain yield ranging from 1806 to 1954 kg ha−1 The third group, with grain yield of 1498 to 1759 kg ha−1 contained mostly Striga‐susceptible cultivars and the C0 of the selection program. Under Striga‐free conditions, the performance of several cultivars from the selection program was equal to or better than ACR 94 TZE Comp5‐Y and ACR 94 TZE Comp5‐W. The genotype plus genotype × environment interaction biplot analysis demonstrated that EV DT‐Y 2000 STR C1 and TZE‐W Pop DT STR C3 from the selection program, along with ACR 94 TZE Comp5‐W, had stable grain yield under Striga‐infested and noninfested conditions.

been removed from the soil by leaching or via harvested crops (Granados et al., 1993). Acidic soils, therefore, Soil acidity reduces maize (Zea mays L.) yields by up to 70% on generally have a low pH, contain toxic levels of Al and 8 million hectares in developing countries. Several breeding programs have produced populations better adapted to these conditions. TheMn, and are deficient in Ca, Mg, P, K, and Mo. These objectives of this study were to evaluate these populations for both characteristics limit the fertility of acid soils and inhibit per se cultivation and the development of new breeding germplasm. root development, leading to low water and nutrient up-To do so, we generated a diallel cross design, which included six acid take and low maize yields (Duque-Vargas et al., 1994). soil-tolerant and five susceptible populations with high yield potential Soil amendments (the application of lime and fertilizor tolerance to other stresses. Populations and crosses were evaluated ers) have been used to bring acid soils under agricultural in five environments, on acidic Al-toxic soils and in comparable limed production. However, such solutions may not be envisoils in Guadeloupe, Cameroon, and Colombia. Soil acidity decreased ronmentally friendly, have only a temporary effect, and grain yield by 46 to 73%, depending on the location and year. Signifiare too expensive for poor farmers in developing councant genotype ϫ soil condition interactions were observed for grain tries (The et al., 2001). The use of acid soil-tolerant maize yield. Mid-parent heterosis for yield was significantly higher in acid soils (32%) than in nonacid soils (20%). This suggests that the develop-cultivars provides an environmentally friendly, inexpenment of variety crosses between acid soil-tolerant populations could sive, and permanent solution, contributing to sustainbe used to increase maize yields in acid-soil cropping systems. The able crop production on acid soils (Granados et al., observed high general combining ability (GCA) for yield variation of 1993). the crosses in acid soil and its close relationship to per se performance Considerable genetic variation in acid-soil tolerance suggest that parental populations of variety crosses could be efficiently has been reported in maize. Early studies demonstrated screened on the basis of per se performance in acid soil.

can also be described as tolerance, in that high grain yields are The parasitic witchweed, Striga hermonthica (Del.) Benth, is the greatest attained in the presence of reduced host plant damage by Striga

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An experiment was conducted for 4 years to assess the effectiveness of fallow, slash and burn farming systems on maize grain yield and soil chemical characteristics. It was also meant to measure the response to yearly rotation of maize and leguminous crops The et al.; IJPSS, Article no. IJPSS.2012.001 Research Article