Now showing items 41-60 of 7933

    • Feed the Future: Nigeria Integrated Agriculture Activity - 33rd Edition 

      USAID; International Institute of Tropical Agriculture (NIIA Newsletter, 2024-02)
    • Enhancing cowpea tolerance to elevated temperature: achievements, challenges and future directions 

      Mohammed, S.B.; Ongom, P.O.; Togola, A.; Boukar, O. (2024-03-01)
      Despite its ability to thrive in high-temperature environments, cowpea productivity can be hampered by heat stress, particularly when night air temperatures exceed 17 °C. The crop’s germplasm pool potentially possesses significant genetic variability that can be harnessed to breed for heat-tolerant varieties. Progress in improving the crop for heat tolerance has been limited, especially under the hot, short-day environments typical of sub-Saharan Africa. Only a few heat-tolerant varieties have ...
    • A mid-density single-nucleotide polymorphism panel for molecular applications in cowpea (Vigna unguiculata (L.) Walp) 

      Ongom, P.O.; Fatokun, C.; Togola, A.; Garcia-Oliveira, A.L.; Ng, E.H.; Kilian, A.; Lonardi, S.; Close, T.J.; Boukar, O. (2024-01-01)
      Molecular markers are increasingly being deployed to accelerate genetic gain in crop plants. The objective of this study was to assess the potential of a mid-density genotyping panel for molecular applications in cowpea breeding. A core set of 2,602 targeted diversity array technology (DArTag) single-nucleotide polymorphisms (SNPs) was designed from an existing 51,128 Cowpea iSelect Consortium Array. The panel’s usefulness was assessed using 376 genotypes from different populations of known genetic ...
    • Social challenges and opportunities in agroforestry: cocoa farmers’ perspectives 

      Bosselmann, A.S.; Boadi, S.A.; Olwig, M.F.; Asare, R. (Palmgrave Macmillan, 2024)
      Agroforestry practices in cocoa cultivation have historical roots going back to the Mayan sacred groves in Mesoamerica. Today, agroforestry cocoa, i.e., the integration of shade trees, plants and crops in cocoa systems, is promoted as a climate smart practice by public and private institutions. Shaded cocoa can sustain or even increase cocoa yields and the agroforestry systems may provide additional output for household consumption and sale as well as improve the microclimate and soil conditions ...
    • Assessing the impact of genotype-by-environment interactions on agronomic traits in elite cowpea lines across agro-ecologies in Nigeria 

      Popoola, B.; Ongom, P.O.; Mohammed, S.B.; Togola, A.; Ishaya, D.J.; Bala, G.; Fatokun, C.; Boukar, O. (2024)
      The yield of cowpea varieties is affected by environmental variability. Hence, candidate varieties must be tested for yield stability before release. This study assessed the impacts of genotypes, environments, and their interaction on the performance of elite cowpea lines for key adaptive, grain yield, and associated traits across different locations. A total of 42 elite genotypes were evaluated in five Nigerian environments, representing various savanna ecologies, during the 2021 growing season. ...
    • Host plant resistance to insects in pulse crops 

      Togola, A.; Ongom, P.O.; Mohammed, S.B.; Fatokun, C.; Tamo, M.; Boukar, O. (Springer, 2024)
      Pulses are important sources of protein, dietary fiber, vitamins, and minerals for human nutrition and are widely cultivated in many countries around the world. Crops belonging to pulse include mainly chickpeas, mung bean, lentils, pigeon peas, and cowpeas. Pulse production and storage are negatively affected by a variety of biotic and abiotic factors, such as insect pests, diseases, parasites, low soil fertility, heat, and drought. Among these, insect pests have the most significant impact on ...
    • Multi-trait selection index for simultaneous selection of water yam (Dioscorea alata L.) genotypes 

      Ouattara, F.; Agre, A.P.; Adejumobi, I.I.; Akoroda, M.O.; Sorho, F.; Ayolié, K.; Bhattacharjee, R. (2024-01-03)
      Water yam (Dioscorea alata L.) is the most widely cultivated yam species with good agronomic attributes. However, several biotic and abiotic constraints and its lower food quality such as poor pound ability limit its production and use. Therefore, the identification of superior genotypes with suitable characteristics is needed for water yam improvement. This study aims to assess a panel of half-sib (progenies with one parent in common) and full-sib (progenies with the same male and female parents) ...
    • Selection of extra-early white quality protein maize (Zea mays L.) inbred lines for drought and low soil nitrogen resilient hybrid production 

      Annor, B.; Badu-Apraku, B. (2024-01-30)
      In West and Central Africa (WCA), drought and low soil nitrogen (low N) impede increased maize (Zea mays L.) productivity and production. Due to climate change, the two stresses usually occur together, leading to food, nutritional, and economic insecurity in the sub-region. There is, therefore, the need for the development and availability of high-yielding extra-early maturing white Quality Protein Maize (QPM) synthetics and hybrids with resilience to the prevailing stresses through the identification ...
    • Misattribution prevents learning 

      Hoel, J.B.; Michelson, H.; Norton, B.; Manyong, V. (2024)
      In many markets, consumers believe things about products that are not true. We study how incorrect beliefs about product quality can persist even after a consumer has used a product many times. We explore the example of fertilizer in East Africa. Farmers believe much local fertilizer is counterfeit or adulterated; however, multiple studies have established that nearly all fertilizer in the area is good quality. We develop a learning model to explain how these incorrect beliefs persist. We show ...
    • Household economics of cocoa agroforestry: costs and benefits 

      Boadi, S.A.; Bosselmann, A.S.; Owusu, K.; Asare, R.; Olwig, M.F. (Palmgrave Macmillan, 2024)
      Current research suggests that cocoa agroforestry systems could offer stable yields, additional benefits and income from shade trees, despite potential added costs, such as from the purchase of insecticides. There is a paucity of profitability studies of different cocoa agroforestry systems. Only few of them go beyond a narrow focus on cocoa yields to model the entire agroforestry system and thus do not advance our understanding of the socio-economic value of other ecosystem goods. Based on survey ...
    • Feed the Future: gender equality and social inclusion training 

      USAID; International Instittute of Tropical Agriculture (United States Agency for International Development, 2023)
    • Enhancing horticultural productivity, incomes and livelihoods through integrated management of aphid pests on vegetables in sub-Saharan Africa 

      Hanna, R.; Fotso-Kuate, A.; Kumar, P.L.; Djomaha, E.; Toukem, N.; Dongmo, M.; Doumtsop, A.; Ramasamy, S.; Abang, A.; Ekesi, S.; Mohamad, S.; Bayissa, W.H.; Singh, A.B.; Houmgny, R.; Weisser, W.; Keukenou, S.; Ghogomu. T.R. (International Institute of Tropical Agriculture, 2016-09)
      Through several surveys and field trials we determined species composition and distribution of aphids as well as virus incidence on okra and cabbage in Cameroon and okra and kale in Kenya. On cabbage and kale, the cabbage aphid and false turnip aphid were, respectively, most important in higher and lower altitudes. The cabbage aphid in Kenya was associated with both specialist and generalist natural enemies whereas in Cameroon the specialist parasitoid Diaeretiella rapae was absent. Attempts to ...
    • Fertilizer and soil health for enhanced productivity and sustainability in sub- Saharan Africa 

      Vanlauwe, B.; Brown, P.H.; Bruulsema, T.; Dobermann, A.; Hungria, M.; Majumdar, K.; McLaughlin, M.; Wager-Riddle, C.; Zhang, X.; Zhao, F. (Scientific Panel on Responsible Plant Nutrition, 2024-02-06)
    • A new multivariate agricultural drought composite index based on random forest algorithm and remote sensing data developed for Sahelian agrosystems 

      Hanadé Houmma, I.; Gadal, S.; El Mansouri, L.; Garba, M.; Gbetkom, P.G.; Mamane Barkawi, M.B.; Hadria, R. (2023-06-16)
      This manuscript aims to develop a new multivariate composite index for monitoring agricultural drought. To achieve this, the AVHRR, VIIRS, CHIRPS data series over a period of 40 years, rainfall and crop yield data as references were used. Variables include parameters for vegetative stress (SVCI, PV, SMN), water stress (PCI, RDI, NRDI), and heat stress (SMT, TCI, STCI), and a new variable related to environmental conditions was calculated through a normalized rainfall efficiency index. Then, random ...
    • Soybean production manual: good agronomic practices for soybean production in northern Ghana 

      Kermah, M.; Adjei-Nsiah, S.; Ofosu, A. (SSPiNG Project, 2022-05)
    • Evaluating breeding for broad versus narrow adaptation for cassava in Nigeria using stochastic simulation 

      Bakare, M.A.; Kayondo, S.I.; Kulakow, P.; Rabbi, I.Y.; Jannink, J.L. (2024)
      The cassava (Manihot esculenta Crantz) breeding program at the International Institute of Tropical Agriculture (IITA) has adopted genomic selection to accelerate genetic gain. The program continues to develop varieties broadly adapted across Nigeria’s diverse agroclimatic zones. However, genotype by- environment interaction (GEI) presents a challenge for this purpose. To decide whether broad adaptation breeding is a good strategy, we evaluated broad versus narrow adaptation strategies using ...
    • Contribution of Gliricidia sepium green leaf biomass on maize grain nutrient properties 

      Alamu, E.O.; Njoloma, J.; Ngumayo, J.; Akello, J.; Chikoye, D.; Nyoka, I.; Dale, L.; Ray, C.; Mehreteab, T.; Nagothu, U.S. (International Institute of Tropical Agriculture, 2023)
    • Grafting experience and shade influences graft take of avocado scions 

      Ayarna, A.W.; Adjei-Nsiah, S.; Tsukagoshi, S.; Ulsen, J.; Sintim, H.O.; Aduse, P.S.; Bukari, M.; Nkansah, G.O. (2024-02)
      Avocado is an important tree crop grown in the tropics, including Ghana. Avocados are primarily propagated by seed into trees, which grow to provide shade for young cocoa trees and, subsequently, food and income. Cultivation of this crop as a monocrop is limited in Ghana; hence, there is a considerable risk of losing desirable genetic materials. There has been an effort by scientists at the University of Ghana to collect and curate available avocado germplasm to preserve, multiply, and disseminate ...
    • Fertilizer-bioinsecticide synergy improves maize resilience to Spodoptera frugiperda infestation 

      Fiaboe, K.R.; Agboka, K.; Agnamba, A.O.; Teyo, K.L.; Amegah, A.L.; Koffi, D.; Kpadonou, G.E.; Agboka, K.M.; Gwokyalya, R.; Fening, K.O.; Fiaboe, K. (2024-03)
      Fall armyworm (FAW), Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), invasion in Africa has threatened food security. Optimization of plant tolerance and post-infestation recovery are among the management tactics that are being promoted for the integrated management of this pest, but these techniques are poorly studied in sub-Saharan Africa. Our study examined the efficacy of enriched compost, split-NPK fertilization, conventional fertilization, and bioinsecticides on FAW infestation rates, ...