CIMMYT Southern Africa Regional Office

Mount Pleasant, Zimbabwe

CIMMYT Southern Africa Regional Office

Mount Pleasant, Zimbabwe
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Iqbal S.,University of Agriculture, Peshawar | Thierfelder C.,CIMMYT Southern Africa Regional Office | Khan H.Z.,University of Agriculture at Faisalabad | Javeed H.M.R.,COMSATS Institute of Information Technology | And 2 more authors.
Nutrient Cycling in Agroecosystems | Year: 2017

In Pakistan, low crop yields are a common problem of sandy-loam arid and semi-arid agroecosystems. Poor nitrogen use efficiency (NUE) and widespread soil nitrogen (N) deficiency resulting from higher N losses are the main reasons for low yields. Compost may offer a nutrient source in this context as it is relatively stable, has a high NUE and crop N uptake, and may contribute to lower N losses in this region. This research conducted during 2011 and 2012, focused on application of N from poultry manure compost (PMC) and pressmud compost (PrMC) with urea in different ratios (0:0, 100:0, 75:25, 50:50, 25:75, 0:100) for sustainable maize production under the semi-arid conditions of Faisalabad. Overall, combined use of PMC and PrMC with urea in the 2 years increased the grain yield relative to the application of PMC and PrMC on their own. The greatest plant N uptake during the two years from PMC and urea at 25:75 was equivalent to mineral N management (0:100), and it resulted in maximum total grain yield (218.6%) and grain protein (19.8%). This resulted in the lowest N loss from the soil, and the largest NUE (19.1 kg kg−1). Economically, this treatment also provided the greatest net income (932 US$ ha−1), and a benefit cost ratio (2.1). Based on these results, PMC and urea at 25:75 was considered highly beneficial in increasing maize yield while reducing the loss of less-stable N from the soil, increasing NUE and N uptake in inherently poor soils. However, further evaluation is needed to decide whether this N nutrition strategy can be adopted on a wider scale. © 2017 Springer Science+Business Media Dordrecht

MADAMOMBE S.M.,CIMMYT Southern Africa Regional Office | MADAMOMBE S.M.,University of Zimbabwe | NYAGUMBO I.,CIMMYT Southern Africa Regional Office | MVUMI B.M.,University of Zimbabwe | And 3 more authors.
Experimental Agriculture | Year: 2017

Nematode infestation in Sub-Saharan Africa's (SSA) cropping systems, worsened by poor crop rotations, is a major factor contributing to limited utilisation of applied nutrients and water, leading to low maize (Zea mays L.) yields particularly on sandy soils. The effects of nematode infestation on maize productivity were evaluated under conservation agriculture (CA) on granitic sandy soils in sub-humid smallholder farms of Goromonzi district of Zimbabwe. Four treatments were tested for three seasons on six smallholder farmers’ fields in a randomised complete block design, each farm being a replicate: fenamiphos 40EC (a commercial synthetic nematicide), lime + fenamiphos 40EC, lime and an untreated control. Results of the study showed that independent application of fenamiphos 40EC and lime significantly reduced plant parasitic nematode infestations in maize roots by more than 10 times those present in the untreated plots while maize yield also increased significantly. Yield increase from fenamiphos and lime applications amounted to 53 and 42% respectively, compared to the untreated controls. Maize yield was negatively correlated with density of Pratylenchus spp. nematodes. Nematode management strategies involving fenamiphos 40EC or lime could significantly reduce maize yield losses in maize-based smallholder farming systems of SSA under CA. It was more economical to use fenamiphos than lime to control nematodes. Copyright © Cambridge University Press 2017

Ndoli A.,Wageningen University | Baudron F.,CIMMYT Southern Africa Regional Office | Schut A.G.T.,Wageningen University | Mukuralinda A.,World Agroforestry Center | Giller K.E.,Wageningen University
Field Crops Research | Year: 2017

In the sub-humid parts of East Africa, high population density and pressure on land have led farmers to integrate multipurpose trees on farm. Although mixing trees and crops generates numerous benefits (e.g., fuelwood, timber), it often reduces crop yields. Whereas the effects of mature trees on crops are well studied in semi-arid parklands, there are only few studies for the sub-humid environment. The effects of mature Alnus acuminata (Kunth) and Markhamia lutea (Seem.) on crops were studied on-farm for four seasons in the sub-humid environment of northern Rwanda. Five sampling points for A. acuminata and M. lutea were: (i) 1 m from tree trunk without maize, (ii) 3 m from tree trunk without maize, (iii) 1 m from tree trunk with maize, (iv) 3 m from tree trunk with maize and (v) sole maize away from any tree. Nutrient availability and uptake, soil water, air temperature, solar radiation, crop growth and yields were measured. The APSIM-maize module was used to assess the sensitivity of maize yields to changes in these variables. Nutrients availability was higher under A. acuminata compared with M. lutea, because of higher litter fall but maize nutrient uptake increased only under A. acuminata 3 m from tree trunk during a wetter season. None of tree species affected water availability for maize in the topsoil. Photosynthetically active radiation (PAR), total solar radiation and day air temperature were reduced by both tree species. Maize crop at 1 m and 3 m from the tree trunk was shorter in height but had the same number and size of leaves when compared to sole maize plots. Crop yield was generally reduced more at 1 m than at 3 m from the tree trunk. A positive interaction between A. acuminata and maize was only apparent at 3 m from the tree in one of the four seasons following higher litter fall, suggesting that the negative effect of shade was offset by extra N input during that season. In a modelled scenario under low N fertilization, larger N input from trees could compensate for yield loss caused by reduction in radiation and temperature in about 60% of the seasons. Our findings suggest that adequate pruning and high leaf litter recycling can reduce the negative effect of shade in low intensity farming systems. © 2017 Elsevier B.V.

Ndhlela T.,Crop Breeding Institute | Herselman L.,University of the Free State | Semagn K.,CIMMYT | Magorokosho C.,CIMMYT Southern Africa Regional Office | And 2 more authors.
Euphytica | Year: 2015

Genetic characterisation of breeding lines is of great importance as it enables breeders to maximise heterosis in hybrid combinations as well as in the breeding material. In this study 10 Department of Research and Specialist Services and 13 Centre for the Improvement of Maize and Wheat inbred lines were crossed using a North Carolina II mating scheme and were genotyped using 1,129 single nucleotide polymorphic (SNP) markers. The resultant 72 single cross hybrids together with eight different local checks were evaluated across seven locations in Zimbabwe in the 2009/2010 and 2010/2011 seasons. SNP markers yielded a total of 2,258 alleles and a moderate genetic diversity and polymorphic information content of 0.32 and 0.258, respectively. Clustering of lines did not relate to available pedigree information. Significant positive correlations were recorded for specific combining ability with mid parent heterosis (MPH), high parent heterosis (HPH) and per se performance of hybrids. However, correlations of genetic distances with heterosis under drought conditions were too low to be of predictive value. The HPH and MPH also showed significant positive associations along with high coefficients of determination with per se performance of hybrids, especially under drought. © 2015, Springer Science+Business Media Dordrecht.

Ndhlela T.,Crop Breeding Institute | Herselman L.,University of the Free State | Magorokosho C.,CIMMYT Southern Africa Regional Office | Setimela P.,CIMMYT Southern Africa Regional Office | And 2 more authors.
Crop Science | Year: 2014

Maize (Zea mays) is the most important cereal crop in Zimbabwe and is grown by both large-and small-scale farmers who are located in different agro-ecological zones of the country. The development and dissemination of adapted and high-yielding maize cultivars to these agro-ecological zones involves conducting multi-environment trials (METs). This study was conducted with the objectives of i) understanding complex G × E interaction and stability of single cross hybrids generated using CIMMYT elite drought tolerant lines and Department of Research and Specialist Services (DR&SS) elite drought susceptible lines for grain yield across stress and nonstress environments and ii) to identify genotypes to recommend for further use in the breeding program. Initially, yield data of 80 maize single cross hybrids tested across seven environments during the 2009 to 2010 and 2010 to 2011 seasons were analyzed using the additive main effects and multiplicative interaction (AMMI) biplot method. The analysis was further done for 20 best performing genotypes to facilitate less congested graphical presentation. Combined analysis of variance showed highly significant differences for the G × E interaction, indicating the possibility of selection for stable genotypes. The five AMMI interaction principal component analyses (IPCAs; IPCA1, IPCA2, IPCA3, IPCA4, and IPCA5) explained 82.41% of the variation and they were highly significant. The results showed three genotypes with high yield performance and broad adaptability whilst narrow adaptations were also observed. Agricultural Research Trust Farm was the most powerful site in discriminating among genotypes and the most representative environment. © Crop Science Society of America.

Araus J.L.,University of Barcelona | Cairns J.E.,CIMMYT Southern Africa Regional Office
Trends in Plant Science | Year: 2014

Constraints in field phenotyping capability limit our ability to dissect the genetics of quantitative traits, particularly those related to yield and stress tolerance (e.g., yield potential as well as increased drought, heat tolerance, and nutrient efficiency, etc.). The development of effective field-based high-throughput phenotyping platforms (HTPPs) remains a bottleneck for future breeding advances. However, progress in sensors, aeronautics, and high-performance computing are paving the way. Here, we review recent advances in field HTPPs, which should combine at an affordable cost, high capacity for data recording, scoring and processing, and non-invasive remote sensing methods, together with automated environmental data collection. Laboratory analyses of key plant parts may complement direct phenotyping under field conditions. Improvements in user-friendly data management together with a more powerful interpretation of results should increase the use of field HTPPs, therefore increasing the efficiency of crop genetic improvement to meet the needs of future generations. © 2013 Elsevier Ltd.

Nyakudya I.W.,Bindura University of Science Education | Stroosnijder L.,Wageningen University | Nyagumbo I.,CIMMYT Southern Africa Regional Office
Agricultural Water Management | Year: 2014

Realising that rainwater harvesting (RWH) improves crop productivity, smallholder farmers in semi-arid Zimbabwe modified contour ridges traditionally used for rainwater management by digging infiltration pits inside contour ridge channels in order to retain more water in crop fields. However, scientific studies on crop yield benefits of infiltration pits have not been conclusive. Combining field-edge RWH methods such as contour ridges with infiltration pits with in-field practices may enhance crop yield benefits. Thus, the objective of the study was to assess soil moisture and maize yield improvement of combining infiltration and planting pits. Field experiments were conducted in Rushinga, Zimbabwe for three seasons at three sites using a split-plot design: main-plot factor, field-edge rainwater management method (RWMM); and split-plot factor, tillage method. Soil moisture content was measured weekly using gravimetric and Time Domain Reflectometry (TDR) methods. A household and field survey to establish farmers' perceptions, typology and availability of field-edge RWMM was conducted. In order to share experiences and enhance stakeholders' learning, field days were held. Lateral movement of soil water was measured up to 2m downslope from infiltration pits, hence infiltration pits did not improve maize yield and soil moisture content in the cropping area. Maize yield (kgha-1) was 45% higher under conventional tillage (2697) than planting pits (1852) but the yield gap decreased from 90 to 30% in the first and third year respectively. The value of infiltration pits is in reducing soil erosion by water and growing high value horticultural crops inside and close to pits, a view shared by host farmers and other stakeholders. Planting pits are an option for farmers without access to draught power and a fall-back method. Research is required to determine soil moisture, maize yield benefits and waterlogging risk in fields with underlying impermeable layers that enhance lateral flow of water. © 2014 Elsevier B.V.

Mupangwa W.,CIMMYT Southern Africa Regional Office | Mutenje M.,CIMMYT Southern Africa Regional Office | Thierfelder C.,CIMMYT Southern Africa Regional Office | Nyagumbo I.,CIMMYT Southern Africa Regional Office
Renewable Agriculture and Food Systems | Year: 2016

Continuous conventional tillage coupled with unsystematic cereal/legume rotations has promoted low crop productivity on smallholder farms. A multi-locational study was established in three agro-ecoregions (AEs) of Zimbabwe. The aim of the study was to determine the effect of four tillage systems (conventional plowing, planting basins, rip-line and animal traction direct seeding systems) on maize (Zea mays L.), cowpea [Vigna unguiculata (L.) Walp] and soybean [Glycine max (L.) Merrill] yields, and evaluate the economic performance of the conservation agriculture (CA) systems relative to conventional plowing. Each farmer was a replicate of the trial over the three cropping seasons. In the high (750–1000 mm per annum) and low (450–650 mm) rainfall AEs, conventional practice and CA systems gave similar maize grain yield. Under medium rainfall conditions (500–800 mm) planting basins, rip-line and direct seeding systems gave 547, 548 and 1690 kg ha−1 more maize yield than the conventional practice. In the high and low rainfall AEs, conventional practice and planting basins had the lowest maize production risk. Cowpea yield was 35 and 45% higher in the rip-line and direct seeding than conventional practice. Soybean yield was higher in rip-line (36%) and direct seeding (51%) systems than conventional practice. Direct seeding system gave the highest net benefits in all AEs. A combination of long-term biophysical and socio-economic assessments of the different cropping systems tested in our study is critical in order to fully understand their performance under different AEs of Zimbabwe. Copyright © Cambridge University Press 2016

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