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Integrating strip cropping with grass border enhances soil fertility, maize grain, and nutritional yields in Zimbabwean smallholder farming systems
No full textSmallholder maize production in sub-Saharan Africa is constrained by soil fertility decline and erratic rainfall, leading to low dietary diversity. A four-season on-farm study (2018/2019–2021/2022) was conducted with six farmers in Murehwa District, Zimbabwe, to evaluate the effects of maize–legume strip cropping on soil nutrient dynamics, crop yield, and total system nutritional yield. The experiment was a 2 × 6 factorial arranged in a split-plot randomized complete block design, comparing sole maize with maize strip-cropped with pigeonpea (Cajanus cajan (L.) Mills), cowpea (Vigna unguiculata L. Walp.), lablab (Lablab purpureus (L.) Sweet), velvet bean (Mucuna pruriens (L.) DC), and groundnut (Arachis hypogaea L.), with and without Brachiaria ssp. (cv. Mulato II (CIAT36087) grass border. Rainfall ranged from 495 to 1053 mm, influencing crop and soil responses. Strip cropping affected soil properties between the 2020/21 and 2021/22 seasons, notably pH, exchangeable potassium (K), and soil organic carbon (SOC). Maize + cowpea improved K (+65 %) and pH (+30 %), while maize + groundnut improved SOC (+5 %). Maize grain yield was strongly influenced by season and its interaction with the strip cropping system. Maize + velvet bean yielded 2.4 t ha−1 in 2018/19 and 2020/21, although sole maize produced the highest overall yield (3.2 t ha−1). Maize + pigeonpea consistently produced the highest grain yield among legumes (≈1.0 t ha−1) and total system protein yield (>0.3 t ha−1), while starch yield was highest under sole maize in 2020/21. Overall, maize-legume strip cropping, particularly pigeonpea, cowpea, and groundnut, improved system-level nutrient yield and selected soil properties, demonstrating its potential for climate-resilient smallholder farming
Dialogical training guide for sustainable soil and crop management in smallholder farming systems
No full textThe user of this guidebook may be surprised to find it includes more questions than facts!! This approach grows out of a belief that the best learning comes when facilitators and participants join together in a genuine dialogue. Facilitators may bring knowledge of the scientific world, but farmers best know the reality of their community and farming system. The lecture format, where a teacher talks and the students passively receive information, is replaced by a dialogue in which all parties discuss the reality of their lives, and work together to identify solutions and action plans.viii, 94 page
Do Chameleon Moisture Sensors adopted by farmers increase their irrigation intensity and yields? A proof-of-concept field experiment
No full text14 page
Breeding and deploying high-zinc maize in the tropics
No full textHigh-zinc maize offers a promising solution to alleviate this micronutrient malnutrition, particularly in the Global South. Maize, as a C4 crop, shows potential in addressing declining zinc levels in the face of environmental stressors, but achieving optimal zinc concentrations in maize kernels requires targeted breeding efforts. This chapter highlights the genetic variability of kernel zinc concentration in maize germplasm, considering the complexities of trait inheritance and the influence of genotype-environment interactions. Conventional breeding strategies, alongside modern tools such as QTL mapping, genome-wide association studies (GWAS), and genomic selection (GS), have been instrumental in developing high-zinc varieties. Data from efforts in Latin America and Africa reveal that these varieties can perform competitively in terms of yield and agronomic traits. The bioavailability of zinc in biofortified maize is discussed, alongside the nutritional benefits it provides, particularly in traditional maize-based diets. Key challenges, such as potential yield penalties and the need for consumer acceptance, are explored, with emphasis on combining nutritional improvement with essential agronomic traits like disease resistance and yield stability. The broader opportunities for scaling high-zinc maize are also considered, underscoring the role of collaborative efforts and public-private partnerships in ensuring the sustainable adoption of these nutritionally enhanced varieties.41-6
Mitigating the challenges of transboundary viral disease in Sub Saharan Africa – Maize Lethal Necrosis (MLN): A global model to stop transboundary plant disease threats and secure Africa’s maize future
No full text16 slide
Linkage map construction and QTL mapping for morphological traits in Ipomoea trifida, a diploid sweetpotato relative
No full textIpomoea trifida G. Don (2n = 2x = 30) is considered the closest known diploid relative and a wild ancestor of the autohexaploid sweetpotato, Ipomoea batatas (L.) Lam. (2n = 6x = 90). This study aimed to map quantitative trait loci (QTLs) in a diploid full-sib population (M9 × M19) consisting of 210 progenies based on a high-density genetic linkage map constructed with single-nucleotide polymorphisms (SNPs). In a randomized complete block design with four replications, the phenotypic evaluation of 11 morphological traits was conducted for 188 individuals in 2016 at the International Potato Center under screenhouse conditions in San Ramón, Peru. Heritabilities ranged from 0.30 to 0.80, and genetic correlations varied from −0.22 to 1. An integrated genetic map was constructed with 15 linkage groups and 6410 SNPs spanning 2440.47 cM using the Onemap v.3.0 R package. Major misassemblies were identified and properly fixed on chromosomes 2, 3, and 7. QTL mapping was performed using the composite interval mapping approach for each trait with fullsibQTL v.0.0.901 R package. A total of 37 QTLs were identified, with up to 42.39% of the proportion of phenotypic variance explained by a major QTL on chromosome 3 for a leaf shape-related trait. Reference genome refining and QTL-linked markers contribute to advancing genetic and genomic research on I. trifida and may support sweetpotato breeding programs targeting ornamental traits
Characterization and effect of the introgression of Leymus racemosus into bread wheat
No full textDerivado de la alta demanda que tiene el trigo en el mundo, actualmente se buscan nuevas tecnologías para aumentar su producción, la resistencia a enfermedades, la tolerancia a diferentes estreses y calidad, entre otras. En esta búsqueda, la introgresión de genes mediante el uso de translocaciones entre parientes silvestres y el trigo, ha sido una de las vías más exitosas de mejoramiento. Los objetivos del presente estudio fueron introgresar y caracterizar, en líneas de trigo harinero, la translocación de Leymus racemosus mediante técnicas citogenéticas y marcadores moleculares y determinar el efecto de la translocación sobre la resistencia a la roya de la hoja comparado con el progenitor recurrente. La translocación se ubicó en el brazo largo del cromosoma 5B de trigo harinero Borlaug 100 y fue designada como T5Lr#1L.5BL. El marcador molecular wsnp_Ex_c5915-103 confirmó la presencia de dicha translocación. Las pruebas de resistencia en plántula a la roya de la hoja mostraron que las 38 líneas con la translocación fueron susceptibles, al igual que el progenitor recurrente
