Browsing by Author "Dan Makumbi"

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    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.
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    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.