Browsing by Author "Godfrey Asea"

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Agronomic Evaluation of Alternative Lowland Rice Varieties for Farmers in Uganda; A Case of Aromatic Rice
(Journal of Food Security, 2022-09-16) Simon Alibu; Morish Obura; James Ekebu; Doreen Nampamya; Jimmy Lamo; Godfrey Asea; Tae-Seon Park
Rice has recently become an important crop for tackling food insecurity and poverty in Uganda. Over three-quarters of the country's local rice production occurs in irrigated and rain-fed lowlands in eastern and northern Uganda. However, breeding programs and seed systems have only partially met farmers' expectations for new lowland rice varieties and seeds recently, so farmers are sticking with old varieties. However, a new high-yielding, early-maturing, and most importantly, aromatic variety, NARORICE-1, released in 2019, seems to offer a new ray of hope for lowland rice farmers. This study compared the agronomic performance of NARORICE-1 and two promising KAFACI lines to a popular farmer's variety, WITA-9, in central, eastern, and northern Uganda. These varieties were evaluated for growth and yield response to higher seedling counts per hill when transplanted. Doho was the most productive location with an average rice yield of 6.1 t ha–1, significantly higher than NaCRRI and Olweny with 3.9 and 3.7 t ha–1, respectively. The yield performance of NARORICE-1 was comparable to that of the popular farmer's variety WITA-9. Increasing the number of seedlings per hill from three to seven during transplanting had no clear effect on the paddy yield of NARORICE-1. Besides higher yield potential, NARORICE-1's other additional beneficial traits such as aroma, shorter growing time, and higher milling efficiency have made it one of the growers' favorites.
Efficacy of Event MON 87460 in drought-tolerant maize hybrids under optimal and managed drought-stress in eastern and southern africa
(Journal of Genetic Engineering and Biotechnology, 2024-02-12) Caleb O. Obunyali; Kiru Pillay; Barbara Meisel; Eric N. Ndou; Kingstone Mashingaidze; Julius Pyton Sserumaga; Godfrey Asea; Murenga Mwimali; Regina Tende; Yoseph Beyene; Stephen Mugo; Emmanuel Okogbenin; Sylvester O. Oikeh
Background: Frequent drought events due to climate change have become a major threat to maize (Zea mays L.) production and food security in Africa. Genetic engineering is one of the ways of improving drought tolerance through gene introgression to reduce the impact of drought stress in maize production. This study aimed to evaluate the efficacy of Event MON 87460 (CspB; DroughtGard®) gene in more than 120 conventional drought‐tolerant maize hybrids in Kenya, South Africa, and Uganda for 3–6 years under managed drought‐ stress and optimal conditions and establish any additional yield contribution or yield penalties of the gene in traited hybrids relative to their non‐traited isohybrids. Germplasm used in the study were either MON 87460 traited un‐adapted (2008–2010), adapted traited DroughtTEGO® (2011–2013) or a mix of both under confined field trials. Results: Results showed significant yield differences (p < 0.001) among MON 87460 traited and non‐traited hybrids across well‐watered and managed drought‐stress treatments. The gene had positive and significant effect on yield by 36–62% in three hybrids (CML312/CML445; WMA8101/CML445; and CML312/S0125Z) relative to non‐traited hybrids under drought, and without significant yield penalty under optimum‐ moisture conditions in Lutzville, South Africa. Five traited hybrids (WMA2003/WMB4401; CML442/ WMB4401; CML489/WMB4401; CML511/CML445; and CML395/WMB4401) had 7–13% significantly higher yield than the non‐traited isohybrids out of 34 adapted DroughtTEGO® hybrids with same background genet- ics in the three countries for ≥ 3 years. The positive effect of MON 87460 was mostly observed under high drought‐stress relative to low, moderate, or severe stress levels. Conclusion: This study showed that MON 87460 transgenic drought tolerant maize hybrids could effectively tolerate drought and shield farmers against severe yield loss due to drought stress. The study signified that development and adoption of transgenic drought tolerant maize hybrids can cushion against farm yield losses due to drought stress as part of an integrated approach in adaptation to climate change effects.
Genetic trends for yield and key agronomic traits in pre- commercial and commercial maize varieties between 2008 and 2020 in Uganda
(Frontiers, 2023-03-10) Godfrey Asea; Daniel Bomet Kwemoi; Clay Sneller; Charles L. Kasozi; Biswanath Das; Lennin Musundire; Dan Makumbi; Yoseph Beyene; Boddupalli M. Prasanna
Estimating genetic gains is vital to optimize breeding programs for increased efficiency. Genetic gains should translate into productivity gains if returns to investments in breeding and impact are to be realized. The objective of this study was to estimate genetic gain for grain yield and key agronomic traits in pre- commercial and commercial maize varieties from public and private breeding programs tested in (i) national performance trials (NPT), (ii) era trial and, (iii) compare the trends with the national average. The study used (i) historical NPT data on 419 improved maize varieties evaluated in 23 trials at 6-8 locations each between 2008 and 2020, and (ii) data from an era trial of 54 maize hybrids released between 1999 and 2020. The NPT data was first analyzed using a mixed model and resulting estimate for each entry was regressed onto its first year of testing. Analysis was done over all entries, only entries from National Agricultural Research Organization (NARO), International Maize and Wheat Improvement Center (CIMMYT), or private seed companies. Estimated genetic gain was 2.25% or 81 kg ha-1 year-1 from the NPT analysis. A comparison of genetic trends by source indicated that CIMMYT entries had a gain of 1.98% year-1 or 106 kg ha-1 year-1. In contrast, NARO and private sector maize entries recorded genetic gains of 1.30% year-1 (59 kg ha-1 year-1) and 1.71% year-1 (79 kg ha-1 year-1), respectively. Varieties from NARO and private sector showed comparable mean yields of 4.56 t ha-1 and 4.62 t ha-1, respectively, while hybrids from CIMMYT had a mean of 5.37 t ha-1. Era analysis indicated significant genetic gain of 1.69% year-1 or 55 kg ha-1 year-1, while a significant national productivity gain of 1.48% year-1 (37 kg ha-1 year-1) was obtained. The study, thus, demonstrated the importance of public-private partnerships in development and delivery of new genetics to farmers in Uganda.
Genetic trends in CIMMYT’s tropical maize breeding pipelines
(Nature Journal, 2022-11-22) Boddupalli M. Prasanna; Juan Burgueño; Yoseph Beyene; Dan Makumbi; Godfrey Asea; Vincent Woyengo; Amsal Tarekegne; Cosmos Magorokosho; Dagne Wegary; Thokozile Ndhlela; Mainassara Zaman‐Allah; Prince M. Matova; Kabamba Mwansa; Kingstone Mashingaidze; Pedro Fato; Adefris Teklewold; B. S. Vivek; P. H. Zaidi; M. T. Vinayan; Nagesh Patne; Sujay Rakshit; Ramesh Kumar; S. L. Jat; S. B. Singh; Prakash H. Kuchanur; H. C. Lohithaswa; N. K. Singh; K. B. Koirala; Salahuddin Ahmed; Felix San Vicente; Thanda Dhliwayo; Jill E. Cairns
Fostering a culture of continuous improvement through regular monitoring of genetic trends in breeding pipelines is essential to improve efficiency and increase accountability. This is the first global study to estimate genetic trends across the International Maize and Wheat Improvement Center (CIMMYT) tropical maize breeding pipelines in eastern and southern Africa (ESA), South Asia, and Latin America over the past decade. Data from a total of 4152 advanced breeding trials and 34,813 entries, conducted at 1331 locations in 28 countries globally, were used for this study. Genetic trends for grain yield reached up to 138 kg ha−1 yr−1 in ESA, 118 kg ha−1 yr−1 South Asia and 143 kg ha−1 yr−1 in Latin America. Genetic trend was, in part, related to the extent of deployment of new breeding tools in each pipeline, strength of an extensive phenotyping network, and funding stability. Over the past decade, CIMMYT’s breeding pipelines have significantly evolved, incorporating new tools/technologies to increase selection accuracy and intensity, while reducing cycle time. The first pipeline, Eastern Africa Product Profile 1a (EA-PP1a), to implement marker-assisted forward-breeding for resistance to key diseases, coupled with rapid-cycle genomic selection for drought, recorded a genetic trend of 2.46% per year highlighting the potential for deploying new tools/technologies to increase genetic gain.
Modest Ag-Extension and Access to Seeds of Aromatic Rice Can Boost Returns of Smallholder Farmers in Uganda, A Case Study
(Agriculture Journal, 2022-08-06) Simon Alibu; Morish Obura; James Ekebu; Doreen Nampamya; Jimmy Lamo; Godfrey Asea; Tae-Seon Park
Limited farmer access to quality seeds of improved varieties and knowledge gaps in good agronomic practices are the major factors limiting rice productivity among smallholder farmers in Uganda. Promoting high yielding aromatic rice varieties alongside good agronomic practices can unlock commercial opportunities for smallholder farmers in rice cultivation, given that 80% of rice consumers in Uganda prefer aromatic rice, which is in short supply. This case study highlights a project’s achievements to accelerate the adoption of improved aromatic rice varieties among smallholder farmers in Uganda. This project supported a few selected farmers with the seed of a new aromatic rice variety, NARORICE-1, and equipped them with agronomic skills to raise their yields from an average of 3.1 to 4.1 t/ha. Line transplanting was identified as a crucial technology to increase rice yields among smallholders. Costly and inaccessible crop-enhancing inputs such as seeds and fertilizers, and an unfair distribution of irrigation water were the two main obstacles farmers face in rice production. Farmers valued NARORICE-1 for its aroma, high yield, and early maturity. The project’s training of a community seed producer improved farmers’ access to NARORICE- 1 seeds, increasing its adoption by 20% in two years. NARORICE-1 is much more in demand than any other variety and attracts a better price, making it an ideal innovation for increasing productivity and farmer’s incomes. An effective seed system and continuous farmer training are vital for accelerating impact.
Performance of Bt maize event MON810 in controlling maize stem borers Chilo partellus and Busseola fusca in Uganda
(Crop Protection, 2022-06-05) Michael H. Otim; Simon Alibu; Godfrey Asea; Grace Abalo; Julius Pyton Sserumaga; Stella Adumo; Jane Alupo; Stephen Ochen; Tadele Tefera; Anani Y. Bruce; Yoseph Beyene; Barbara Meisel; Regina Tende; Francis Nang’ayo; Yona Baguma; Stephen Mugo; Sylvester O. Oikeh
Stem borers are major insect pests of maize in Uganda. A study was conducted in 2014–2016 to assess the performance of Bt hybrids expressing Cry1Ab (event MON810) against the two major stem borer species in Uganda – the African stem borer (Busseola fusca) and the spotted stem borer (Chilo partellus) – under artificial infestation. The study comprised 14 non-commercialized hybrids, including seven pairs of Bt and non-Bt hybrids (isolines), three non-Bt commercial hybrids and a conventional stem borer resistant check. All stem borer damage parameters (leaf damage, number of internodes tunneled and tunnel length) were generally significantly lower in Bt hybrids than in their isolines, the conventionally resistant hybrid, and local commercial hybrids. Mean yields were significantly higher by 29.4–80.5% in the Bt hybrids than in the other three categories of non-Bt hybrids. This study demonstrated that Bt maize expressing Cry1Ab protects against leaf damage and can limit entry of stem borers into the stems of maize plants, resulting in higher yield than in the non-transgenic hybrids. Thus, Bt maize has potential to contribute to the overall management package of stem borers in Uganda.