Assessment of early-maturing maize hybrids and testing sites using GGE biplot analysis

Article Purchased; Published: 7 Sept. 2017Identification of outstanding maize (Zea mays L.) hybrids for target environments is complicated by genotype × environment interactions. Thirty-two early-maturity maize hybrids were evaluated at eight locations in Nigeria and six locations in Ghana for 2 yr to (i) identify high-yielding, stable hybrids across locations and/or hybrids specifically adapted to different locations, and (ii) identify ideal test sites for selection of superior hybrids in the two countries. Genotype, country, year, location (country), and their interactive effects were significant (P < 0·01) for grain yield, days to anthesis and silking, anthesis-silking interval, plant and ear aspects, and ears per plant. Mean grain yield of the hybrids ranged from 3177 kg ha−1 for EWH-5 to 4596 kg ha−1 for EWH-29. The genotype main effects plus genotype × environment interaction (GGE) biplot analysis revealed that EWH-29, EWH-8, and EWH-30 did not differ significantly in grain yield and were the most stable hybrids in both countries, whereas EWH-26 and EWH-32 were the most stable hybrids only in Ghana. The GGE biplot analysis identified Samaru, Kafin Soli, and Minjibir in Nigeria and Nyankpala, Damongo, and Fumesua in Ghana as the most discriminating locations. Minjibir (Nigeria) and Nyankpala (Ghana), being most discriminating and representative locations, were considered the ideal testing sites for the respective countries. The type of cultivars evaluated determined the most suitable locations for multilocation testing within Ghana and Nigeria. Whereas hybrids EWH-29, EWH-8, and EWH-30 should be suitable for production in Nigeria, EWH-26 and EWH-32 should be promoted for production in Ghana

Stability analysis of maize cultivars adapted to tropical environments using AMMI analysis

Genotype × environment interactions complicate selection of superior genotypes for narrow and wide adaptation. Eighteen tropically-adapted maize cultivars were evaluated at six locations in Nigeria for 2 yrs to (i) identify superior and stable cultivars across environments and (ii) assess relationships among test environments. Environment and genotype × environment interactions (GEI) were significant (P −1 for TZL COMP4 C3 DT C2 with an average of 2555 kg ha−1. Cultivar DT SYN2-Y had the least additive main effect and multiplicative interaction (AMMI) stability value of 7.4 and hence the most stable but low-yielding across environments. AMMI biplot explained 90.5% and classified cultivars and environments into four groups each. IWD C3 SYN F3 was identified as the high-yielding and stable cultivar across environments. ZA15, ZA14, BK14, BK15 and IL15 had environment mean above the grand mean, while BG14, BG15, LE14, LE15, IL14, LA14 and LA15 had mean below the grand mean. ZA, BK, BG, LE and LA were found to be consistent in ranking the maize cultivars. However, Zaria, Birnin Kudu, and Ilorin were identified as the best test locations and could be used for selecting the superior maize cultivars. The identified high-yielding and stable cultivar could be further tested and promoted for adoption to contribute to food insecurity in Nigeria

Impact of globalisation on domestic family law: multi-tiered marriage in Nigeria as a case study

The concept of globalisation is commonly discussed as an issue in international law. However, little attention is paid to its influence in domestic family law. As a result of the growing trend of globalisation, legal and cultural norms of the host culture and the foreign culture are fused, thereby, leading to cultural homogenisation or cultural hybridisation, depending on the level of accommodation of the foreign norm by the host norm. One of the areas where hybridisation or homogenisation of cultural and legal norms manifests, especially in African countries including Nigeria, is in the marriage system, particularly in the conclusion of marriage contracts. In Nigeria, one of the impacts of cultural hybridisation is the evolvement of multi-tiered marriage, where a couple combines marriages under the statute law, customary law and religious law, especially Islamic law. This paper is an exploratory study of how globalisation impacts on how and why multi-tiered marriage is contracted in contemporary Nigeria. The paper also briefly discusses how the combination of marriages as a response to globalisation affects the operation of family law rules in Nigeria as well as the rights of the parties involved, especially the women