IITA Conference Documents
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Item The importance of grain legumes in cropping systems in Africa(Conference Proceedings, 1975) Nangju, D.Grain legumes play an important role in cropping systems in Africa by virtue of their short duration, drought tolerance, ability to fix nitrogen from atmospheric air, and ability to grow in depleted soils and in association with cereals and root crops. In addition, grain legumes are important sources of vegetable proteins, vitamin B and calcium particularly for vegetarian diets during the hungry season. Different species of grain legumeg are grown in various forms of cropping systems. Their performance under mixed cropp ins system and their contribution to soil fertility are reviewed. It is concluded that under the present management practices in Africa, grain legumes probably contribute very little toward maintaining or enhancing soil fertility, and that higher yields obtained under mixed cropping may be attributed mainly to greater utilization of environmental resources, and lower incidence of diseases and insects. Research is urgently required to improve the contribution of grain legumes to nitrogen requirements of companion crops or the following crops in view of the high cost of nitrogen fertilizers.Item The IITA farming systems program(Conference Proceedings, 1974) Okigbo, B.The International Institute of Tropical Agriculture (IITA) was established in 1967 on 1,000 hectares of land located at 3o 54'E longitude and 7o 30'N latitude, about 16 kiloneters north of Ibadan, the capital of the Western State of Nigeria. It is one of a network of international research institutes where priority is given to research, training and related activities aimed at quantitatively and qualitatively increasing food production in the developing countries of the world. These countries contine to experience shortages in available food supplies resulting from much higher rates of population growth as compared to the rates of increase in food production. Specifically, IITA's activities involve multidisciplinary, problem-oriented research in food crops production which, for effectiveness and rapid progress, is restricted to the major food crops of the humid tropics. The humid tropics is defined as the broad belt girdling the earth in the lower latitutes on both sides of the equator where precipitation exceeds evaporation for more than half the year and where normally the tropical rain forest constitutes the climax vegetation.Item P40: Rate of seed transmission of bean common mosaic virus (BCMV) in successive generations in cowpea(Abstract, 2025) Dauda, N.; Ajamu, D.; Baiyeri, P.K.; Ugwuoke, K.I.; Kumar, P.L.This study aimed to understand the effect of genotype, time of infection, and seed morphometrics on seedborne virus infections in cowpea (Vigna unguiculata) transmission and the eventual impact of seed-borne viruses on cowpea yield compared to uninfected control. Experiments were performed using a Potyvirus species, bean common mosaic virus-blackeye (BCMV-BlCM). This virus is endemic in West Africa. Nine cowpea genotypes raised in 6-inch pots and maintained in an insect-proof screenhouse were mechanically inoculated at 7, 21, and 40 days after planting (DAP). Seeds obtained from both the inoculated and uninoculated control groups were planted, and the seedlings were examined for seedborne infection based on symptoms and RT-PCR diagnostics. All identified seed-borne plants were maintained until harvest and re-evaluated for seed transmission and the impact of seedborne viruses on cowpea yield in successive generations. In the first generation, percent BCMV seed transmission rates of 7.9, 4.6, and 44.4 were observed in genotypes RS018 inoculated at 21 DAP, RS075 (7 DAP), and RS012 (DAP). In the second generation, 35.1%, 0%, and 34.1% transmission rates were reported for the same genotypes. Significant reduction in seed yield and prolonged days to phenology was observed in seedborne plants when compared to uninfected controls. Early-stage protection against virus infection will reduce the risk of seed transmission in cowpeas.Item Implications of high throughput sequencing of plant viruses in biosecurity – a decade of progress?(Abstract, 2025) Fox, A.; Botermans, M.; Ziebell, H.; Fowkes, A.R.; Fontdevila, N.; Massart, S.; Rodoni, B.; Chooi, K.M.; Kreuze, J.; Kumar, P.L.; Cuellar, W.J.; Carvajal-Yepes, M.; Macdiarmid, R.M.In the 15 years since High Throughput Sequencing (HTS) was first used for the detection and identification of plant viruses, the technology has matured and is now being used in frontline plant biosecurity applications. Anticipating the challenges this new approach was starting to reveal, recommendations were made a decade ago to streamline the application of these technologies (MacDiarmid et al., 2013). The recommendations were (1) for countries to increase baseline surveillance, (2) to address nomenclature for “data inferred” new viral sequence to differentiate from characterised viruses, and (3) to increase the focus on fundamental biological research to deal with the deluge of new virus discoveries. The progress made on these recommendations in the intervening decade has been as much about changing philosophical approaches as about advancing practical research. As we move towards a potential asymptote in the rate of virus discovery, the anticipated future challenges posed by the broader adoption of HTS in routine biosecurity applications need to be considered. In addition to these three recommendations, which remain relevant, a fourth recommendation is becoming necessary: (4) to ensure equal inclusion and access to research and technology, both locally and globally, with a particular emphasis on countries in the global south. The potential impact of these recommendations on researchers, risk analysts, biosecurity authorities, and policymakers at national and international levels to achieve a reduction of biosecurity incursions of phytopathogenic viruses will be discussed.Item Between isomorphism and entrepreneurship: the impact of standardisation on product quality, market access and livelihoods in Kenyan banana production(Abstract, 2011-10) Matui, M.S.; Ingenbleek, P.; Linnemann, A.; van Trijp, H.; Abass, A.Item Delivering innovative research towards inclusive adoption of climate-smart agriculture for food and nutritional security: Book of Abstracts for the 26th Annual Symposium of the International Association of Research Scholars and Fellows(Conference Proceedings, 2023-11-30) International Association of Research Scholars and FellowsItem Seed propagation trends in Nigeria and Ghana(Abstract, 2023) Balogun, M.Item Relative performance of old and newly released yam varieties in hydroponics system for seed yam production(Abstract, 2023) Balogun, M.; Ekundayo, M.; Ossai, C.; Jimoh, L.; Maroya, N.; Aighewi, B.; Mignouna, D.; Amele, A.; Legg, J.Rapid multiplication of improved yam varieties is crucial to enhance farmers’s access to seeds. Seed yam production has been enhanced using hydroponics system. However, reports on use of hydroponics have been for few improved genotypes released at least one decade ago. This study assessed the amenability of released / near-release yam genotypes to hydroponics substrates. Two weeks old Breeder seedlings of three released varieties of Dioscorea alata (Akuabata, VaYam and Wonder) and four genotypes of Dioscorea rotundata (Released: Kpamyo and Asiedu, and near-release: Danacha and Meccakusa) were planted in the following hydroponics susbtrates; Riversand, Riversand+Ashed Ricehusk (RS+AH: 3:1), Cocopeat, Cocopeat+Ashed Ricehusk (CP+ASH: 3:1) and Ash. Fertigation was daily with nutrient solution as described previously. Data were taken on the Number of Single Node Vine Cuttings (SNVC) f rom 18 stands at 2 Weeks after Planting (WAP), Percentage Vine Survival (PVS), Number of Nodes (NON) at 6WAP, Number of Tubers (NOT) and Tuber Weight (TW) g at harvest. Data were analysed using ANOVA , and means were separated using Least Signif icant Differences at P=0.05. The SNVC, PVS, NON, NOT and TW of the genotypes differed signif icantly and ranged from 220 (Wonder) to 596 (Asiedu), 33.8% (VaYam) to 95.4% (Danacha), 16.0±1.4 (Danacha) to 35.1±1.4 (Asiedu), 1.4±0.1 (Danacha) to 1.9±0.1 (Akuabata), and 16.6±2.6g (Wonder) to 40.3±2.6g (Asiedu), respectively. The substrate effect on SNVC, PVS, NON, NOT and TW ranged f rom 143 (CP+AH) to 577 (RS+AH), 42.7% (CP+AH) to 60.9% (Riversand), 4.33±1.1 (Ash) to 30.3±1.1 (RS+AH), 1.0±0.1 (Ash) to 2.1±0.1 (RS+AH), and 1.4±2.3g (Ash) to 50.3±2.3g (Riversand), respectively. Genotype by substrate interactions were also signif icant. Asiedu gave the highest vine production in the hydroponics system relative to the near release varieties, but the near-release varieties Danacha and Akuabata had higher vine survival rate and number of minitubers, respectively. The implications of these f findings in evolution of the formal yam seed system are discussed.Item Prospects and challenges of emerging yam formal seed systems in West Africa(Abstract, 2023-10) Aighewi, B.; Aihebhoria, D.; Balogun, M.; Mignouna, D.Yam (Dioscorea spp.) is a staple tuber crop produced in parts of tropical Af rica, the Caribbean, Oceania, and South Asia. Typically, the crop is grown in traditional systems where there are no dedicated seed producers and farmers use seed f rom informal sources. Recently, technologies developed at the International Institute of Tropical Agriculture, Nigeria, were deployed to initiate formal yam seed systems in Nigeria and Ghana to enhance the availability of quality seed to millions of yam farmers in West Af rica. A study was conducted using a structured questionnaire to investigate how seed companies that engage in foundation and certified seed yam production were using the new technologies, and to assess the prospects for increasing the availability of quality seed through the formal seed system, as well as the challenges encountered. Results showed that seed companies were satisf ied using new technologies such as <10 g minitubers of improved varieties, compared to the 250 g seeds of landraces in informal production systems. They also use leaf-bud cuttings in hydroponic systems in screenhouses with up to 92% plant establishment, and 65% of the companies use locally available rice husk as a growth substrate. The improved practices used in screenhouses and f ields that are inspected and certified by the relevant quality control and certification agencies have great potential in enhancing the availability of quality seed yam. However, the aeroponic system was considered complicated and expensive, and not adopted despite the 95 to 97% plant survival in the system. Major challenges of the new system include limited knowledge on the storage requirement for 1 - 10 g foundation seeds and high storage losses (up to 38%) resulting from nematode infestation when seed was produced in the field. There is also an unwillingness by farmers to accept new varieties. In conclusion, the adoption of new technologies in the formal seed system with additional knowledge on storage and pest control will mitigate major bottlenecks in quality seed yam production and availability.Item Varietal characteristics of cassava: farmers' perceptions and preferences in semiarid zone of west Africa(Conference Paper, 2003-09) Kormawa, P.; Tshiunza, M.; Dixon, A.; Udo, E.; Okoruwa, V.The study examines and models Farmers' perceptions and preferences of cassava· varietal characteristics vis-i-vis the decision ' to adopt cassava cultivars in their fields. The paper is built on the concept of the effect of technology-specific factors on adoption. By way of threshold decision modelling for each of the countries considered, the results reveal different scenario. Based on the varietal characteristics considered, environmental resistance quality (ERQ), high-yielding quality (HYQ), early maturing qualities (EMQ), leaf quality (LQ), inground storability quality (lSQ) and taste quality (TQ) have declining importance in the order of Iisting. As such, environmental resistance quality appears a major varietal characteristic that the farmers perceived and preferred for cultivating any cassava cultivar in the zone. The results, therefore, reinforce the relative importance of varietal characteristics in the choice and preference of cassava cultivars by farmers; it is, therefore, imperative for breeders to develop cultivars that will be acceptable to the farmers considering their level of preference and perceptions.Item Banana bunchy top virus threat to African bananas(Conference Proceedings, 2022-09-07) Kumar, P. LavaThe banana bunchy top virus (BBTV) is threatening livelihoods and banana biodiversity in sub-Saharan Africa. Since the first report in the 1960s, the virus has spread to 17 countries, eight of those in the last decade, including a recent spread in Uganda and Tanzania. In the "2022 International Plant Protection Convention Regional Workshop for Africa," organized by the FAO-IPPC, the African Union-Inter-African Phytosanitary Council (AU-IAPSC), the Plant Protection Organization of Kenya (KEPHIS), and FAO, the BBTV emergence in EA, along with other emerging threats in Africa, was discussed to strategies control actions. The event was held in a hybrid format from 6-8 Sep-2022 in Nairobi and was attended by 58 participants from 22 countries. The summary of BBTV status and recommendations for control was made through the presentation. It has led to the FAO allocation of emergency funds for BBTV management in EA through TCP (Technical Action Program) for 2023.Item Direct planting versus transplanting of yam leaf-bud cuttings for seed production(Conference Paper, 2022-11) Aighewi, B.; Maroya, N.; Aihebhoria, D.; Balogun, M.; Mignouna, Djana B.; Asiedu, R.Item Gene editing of banana for disease resistance(Conference Proceedings, 2022-10-08) Tripathi, L.Item Promotion of soybean as nutritious food, livestock feed and edible oil in Tanzania(Conference Proceedings, 2022) Baijukya, F.Item Prediction of root biomass in cassava based on ground penetrating radar phenomics(Journal Article, 2021-12-03) Agbona, A.; Teare, B.; Ruíz Guzman, H.; Dobreva, I.D.; Everett, M.E.; Adams,T.; Montesinos López, Osval A.; Kulakow, Peter A.; Hays, D.B.Cassava as a world food security crop still suffers from an inadequate means to measure early storage root bulking (ESRB), a trait that describes early maturity and a key characteristic of improved cassava varieties. The objective of this study is to evaluate the capability of ground penetrating radar (GPR) for non-destructive assessment of cassava root biomass. GPR was evaluated for this purpose in a field trial conducted in Ibadan, Nigeria. Different methods of processing the GPR radargram were tested, which included time slicing the radargram below the antenna surface in order to reduce ground clutter; to remove coherent sub-horizontal reflected energy; and having the diffracted energy tail collapsed into representative point of origin. GPR features were then extracted using Discrete Fourier Transformation (DFT), and Bayesian Ridge Regression (BRR) models were developed considering one, two and three-way interactions. Prediction accuracies based on Pearson correlation coefficient (r) and coefficient of determination (R2) were estimated by the linear regression of the predicted and observed root biomass. A simple model without interaction produced the best prediction accuracy of r = 0.64 and R2 = 0.41. Our results demonstrate that root biomass can be predicted using GPR and it is expected that the technology will be adopted by cassava breeding programs for selecting early stage root bulking during the crop growth season as a novel method to dramatically increase crop yieldItem Machine learning model accurately predict maize grain yields in conservation agriculture systems in southern Africa(Conference Paper, 2021-07) Muthoni, Francis K.; Thierfelder, Christian L.; Mudereri, B.T.; Manda, J.; Bekunda, Mateete A.; Hoeschle-Zeledon, IrmgardAdoption of CA in smallholder farmers in Africa is (s)low partly due to poor spatial targeting. Mapping the crop yield from different CA systems across space and time can reveal their spatial recommendation domains. Integration of machine learning (ML) and free remotely sensed big data have opened huge opportunities for data-driven insights into complex problems in agriculture. The objective of this study was to estimate the spatial-temporal variations of maize grain yields from 13-year multi-location on-farm trials implemented across four countries in southern Africa. The agronomic data from the long-term CA trials is used together with gridded biophysical and socio-economic variables. A spatially explicit random forest (RF) algorithm was developed. Spatial variation of yield advantage or loss from CA practices was compared with conventional tillage practices (CP) during seasons with above and below-normal precipitation. The out-of-bag accuracy of the RF model was R 2 = 0.63 and RMSE = 1.2 t ha -1 . The variable importance analysis showed that the altitude, precipitation, temperature, and soil physical and nutrients conditions variables explained most of the variation in maize grain yield. Maps were generated to identify the locations where CA had a yield advantage over CP during seasons with below and above-average precipitation. The CA showed yield gains of up-to 1 t ha -1 during the season with drought compared to CP. In contrast, the CA returned yield losses of similar magnitude during the season with above-normal precipitation, except in Mozambique. The maps on yield advantage will support the spatial targeting of CA to suitable biophysical and socioeconomic contexts. Results demonstrates that multi-source remotely sensed data, coupled with advanced and efficient machine learning algorithms can provides accurate, cost-effective, and timely platform for predicting the optimal locations for the upscaling sustainable agricultural technologies.Item Trends of rainfall onset, cessation, and length of growing season in northern Ghana: comparing the rain gauge, satellite, and farmer's perceptions(Journal Article, 2021-12-13) Atiah, W.A.; Muthoni, Francis K.; Kotu, Bekele Hundie; Kizito, Fred; Amekudzi, L.K.Rainfall onset and cessation date greatly influence cropping calendar decisions in rain-fed agricultural systems. This paper examined trends of onsets, cessation, and the length of growing season over Northern Ghana using CHIRPS-v2, gauge, and farmers’ perceptions data between 1981 and 2019. Results from CHIRPS-v2 revealed that the three seasonal rainfall indices have substantial latitudinal variability. Significant late and early onsets were observed at the West and East of 1.5° W longitude, respectively. Significant late cessations and longer growing periods occurred across Northern Ghana. The ability of farmers’ perceptions and CHIRPS-v2 to capture rainfall onsets are time and location-dependent. A total of 71% of farmers rely on traditional knowledge to forecast rainfall onsets. Adaptation measures applied were not always consistent with the rainfall seasonality. More investment in modern climate information services is required to complement the existing local knowledge of forecasting rainfall seasonality.Item Beyond survival opportunities: enhancing youth livelihoods within the rural space through informed policies in Nigeria(Brief, 2021) Olaosebikan, O.; Teeken, Béla; Bello, A.; Okoye, B.; Crossouard, B.; Sumberg, J.; Madu, TessyItem Commercialising Africa's Agricultural Research Products: perspectives from TAAT(Conference Proceedings, 2020) Opaluwah, A.Item Communicating the TAAT brand(Conference Proceedings, 2018) Opaluwah, A.