Mark Laing

University of KwaZulu-Natal, School of Agricultural, Earth and Environmental Sciences, Faculty Member

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I'm an experienced academic, working in the field of Plant Pathology, especially in biological control and non-chemical control of plant diseases. I also established the African Centre for Crop Improvement to train PhD students from 20 countries in Africa in Plant Breeding of African food crops.

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Noel B. Salazar

KU Leuven

Vinod K K

INDIAN AGRICULTURAL RESEARCH INSTITUTE, NEW DELHI, INDIA

Viktor Fursov

Schmalhausen Institute of Zoology

Simon Springer

The University of Newcastle

Nicola Lupo

LUISS Guido Carli

Dr. Md. Aktaruzzaman

The University of Georgia

Ola A . Galal

Kafrelsheikh University

Elton E Novais Alves

Federal University of Viçosa

Prof Manjit S Kang

Kansas State University

Dr. Farjana Sultana

International University Of Business Agriculture and Technology(IUBAT)

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Papers by Mark Laing

Determination of productivity, rooting and nutrient profile of Acacia mearnsii (black wattle) hedge plants

Australian Forestry, Jul 11, 2023

Correlation and path-coefficient analyses of root yield and related traits among selected sweetpotato genotypes

The South African Journal of Plant and Soil, Nov 27, 2017

The objective of this study was to assess associations between yield and yield-related traits, an... more The objective of this study was to assess associations between yield and yield-related traits, and to identify the most efficient yield-predicting traits in sweetpotato for effective selection. Twenty-five newly developed sweetpotato genotypes were evaluated across six environments using a 5 × 5 simple lattice design with two replications. Data on root yield and yield-related traits were subjected to analysis of variance, correlation and path-coefficient analyses. Root yield was positively and significantly correlated with most traits studied. Root dry matter content (RDMC) had a significant negative correlation with root flesh colour (r = −0.47) and β-carotene content (r = −0.40). Conversely, β-carotene content and root flesh colour showed a highly positive correlation (r = 0.76). Path-coefficient analysis showed that individual root weight, number of roots per plant, RDMC and above-ground fresh weight had highly positive direct effects of 0.821, 0.776, 0.276 and 0.410, respectively, on fresh root yield. These traits also had significant positive correlations with fresh root yield. Vine length and root length, which had highly significant positive correlations with fresh root yield, showed negative direct effects of −0.086 and −0.033, respectively. Therefore, path-coefficient analysis was more valuable in identifying the most influential traits than simple correlation analysis.

Integrated pest management in Southern Africa

Routledge eBooks, Nov 27, 2019

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Adoption and Promotion of Resilient Crops for Climate Risk Mitigation and Import Substitution: A Case Analysis of Cassava for South African Agriculture

Frontiers in sustainable food systems, Apr 15, 2021

Cassava is an important starchy root crop grown globally in tropical and subtropical regions. The... more Cassava is an important starchy root crop grown globally in tropical and subtropical regions. The ability of cassava to withstand difficult growing conditions and long-term storability underground makes it a resilient crop, contributing to food security. Historically, small-scale farmers have grown cassava as a minor crop in the far northeastern part of the country. However, there is an initiative to scale up cassava production, with two discrete areas of interest: large-scale production for industrial starch, and expanding its footprint as a food security crop for small-scale farmers, especially in the context of climate change. In this scoping study, production, processing and marketing data for cassava were accessed from the FAO and US Commercial trade databases. Other domestic market and demand analysis case studies were also explored. There is no cassava data available for South Africa. The study indicated that South Africa imports more than 66,000 tons of starch annually, of which 33% is cassava starch, showing the availability of a local market. The potential of cassava for the South African economy is discussed. Significant industrial opportunities exist for the production and use of cassava in South Africa. However, the realization of these opportunities will depend on the reliable supply of good quality cassava roots. However, the lack of a well-established cassava research program, and a lack of an existing value chain for the industrial scale cassava production and processing are barriers to the development of cassava industry in South Africa. As the initial step to the development of a successful cassava industry, high potential germplasm is imported, characterized and bred for local conditions to ensure the sustainable primary production of cassava. Subsequently, industrial value chains will need to be developed as the optimization of the breeding and agronomy of the crop are completed, and yield potentials are quantified in the different regions of the country.

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Isolation of yeast and Bacillus strains for postharvest control of Penicillium digitatum on citrus fruits in South Africa

Genetic analysis of dual-purpose sweetpotato genotypes using simple sequence repeat markers and phenotypic traits

Journal of Crop Improvement, Apr 1, 2021

ABSTRACT The new generation sweetpotato [Ipomoea batatas L. (Lam.)] varieties are valued as dual-... more ABSTRACT The new generation sweetpotato [Ipomoea batatas L. (Lam.)] varieties are valued as dual-purpose types for food and fodder in the crop-livestock mixed-farming systems in sub-Saharan Africa. The objective of this study was to determine the genetic diversity present among dual-purpose sweetpotato genotypes using simple sequence repeat (SSR) markers and phenotypic traits to identify complementary genotypes for direct production and breeding. Twenty-four sweetpotato genotypes were genotyped using nine selected and highly polymorphic SSR markers and dual-purpose phenotypic traits. The genotypes were field-evaluated using a randomized complete block design with three replications in two representative locations in Rwanda. Genotypes differed significantly (p < 0.05) for dual-purpose traits and other assessed phenotypic traits. Genotype “Ukerewe” had the highest fresh root yield (18.24 t ha−1), followed by genotype ‘8–1038ʹ (17.63 t ha−1). The top-performing genotypes for fresh vine yield were “Wagabolige” (23 t ha−1) and ‘NASPOT13ʹ (21.64 t ha−1). The mean expected heterozygosity value was 0.69, indicating adequate genetic variation in the tested germplasm. Cluster analysis grouped the genotypes into three distinct groups, which aided in the identification of genotypes with high fodder and storage root yields, which were SPK004 and K5132/61 from Group I; 4–160, Ukerewe and RW11-2910 from Group II; and RW11-1860, Wagabolige and 2005–179 from Group III. The identified genotypes should be useful genetic resources for production and development of high-performing dual-purpose sweetpotato cultivars in Rwanda.

Evaluation of candidate orange-fleshed sweetpotato clones for nutritional traits

Acta Agriculturae Scandinavica Section B-soil and Plant Science, May 12, 2017

ABSTRACT Information on the nutrient contents of newly developed orange-fleshed sweetpotato (OFSP... more ABSTRACT Information on the nutrient contents of newly developed orange-fleshed sweetpotato (OFSP) varieties is required for recommendations to growers and the food industry. Therefore, the objectives of this study were to determine the nutritional value of newly developed OFSP clones and to establish the associations between β-carotene content and micro-nutrients for targeted large scale production to alleviate nutrient deficiencies. Seventeen OFSP and eight white/cream-fleshed sweetpotato clones were evaluated across six diverse environments (Halaba, Kokate, Areka, Arbaminch, Hawassa and Dilla) in southern Ethiopia in 2014 using a 5 × 5 simple lattice design. Nutritional traits data were collected on dry-weight basis and subjected to analysis of variance and correlation analyses. Environment, genotype, and genotype × environment interaction effects were highly significant (p < 0.01) for all parameters measured. A newly developed genotype, designated G8, had the highest contents of β-carotene (20.01 mg 100 g−1), protein (7.08%), iron (2.55 mg 100 g−1), zinc (1.42 mg 100 g−1), fructose (4.45%), glucose (5.34%) and sucrose (16.20%). Genotypes G15 and G19 also performed relatively well for the above nutritional traits. The three genotypes, G8, G15 and G19 had mean fresh root yield of 23.5,13.7 and 21.3 tha−1, respectively. These genotypes had root dry matter content of 26.99%, 25.23% and 33.09%, respectively. Β-carotene content had significant positive correlations with iron, zinc, fructose, glucose and sucrose content. This reflects the potential to breed for OFSP varieties enriched with the important micro-nutrients. Overall, the candidate OFSP clones, G8 (Resisto × PIPI-2), G15 (Resisto × Temesgen-23) and G19 (Resisto × Ogansagen-23) were good sources of nutritional traits such as vitamin A, iron, zinc, protein, sucrose, glucose and fructose. The selected genotypes can be recommended for large-scale production, food processing or further sweetpotato improvement to alleviate nutrient deficiencies in Ethiopia or similar environments in sub-Saharan Africa.

Genotype-by-environment interaction for dual-purpose traits in sweetpotato

Journal of Crop Improvement, Jun 18, 2020

Development of high-yielding dual-purpose sweetpotato (Ipomoea batatas [L.] Lam) genotypes is use... more Development of high-yielding dual-purpose sweetpotato (Ipomoea batatas [L.] Lam) genotypes is useful for cultivation in mixed croplivestock farming systems. The objective of this study was to determine genotype-by-environment interaction (GEI) for storage root yield (SRY), vine yield (VY), root: vine ratio (RVR), total above-ground and below-ground biomass (TABGB) and root dry matter content (RDMC) among newly developed sweetpotato clones to select promising dual-purpose clones. Forty-five sweetpotato genotypes, of which 32 were newly developed candidate clones, were evaluated across six diverse environments in Rwanda. Additive main effects and multiplicative interaction (AMMI) and genotype and genotype-by-environment (GGE) biplot analyzes were used to analyze GEI. AMMI analysis revealed a relatively larger proportion of the GEI effect for SRY (31.21%), VY (37.17%), RVR (41.73%), TABGB (35.24%) and RDMC (36.23%) than for genotype and environmental effects, suggesting differential response of test genotypes across environments for the assessed traits. GGE-biplot analysis explained total variation of 72.98% for SRY, 83.26% for VY, 74.03% for RVR, 78.82% for TABGB and 56.78% for RDMC. Clone 21 with enhanced SRY and TABGB, and clone 42 for SRY had broad adaptation. For better VY, clone 733 was the best performer in environments E2 and E6 which are designated as mega-environment (MGE) 2, and clone 321 in E1, E3 and E4 (MGE 3). For RVR, clone 577 had best adaptation in E3, E4 and E5 (MGE 1), while clone 460 in E2 and E6 (MGE 2). Clones 42 and 381 were best performers for RDMC with specific adaptation in environments E3 and E1, respectively.

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Assessment of sorghum genetic resources of Ethiopia for anthracnose ( Colletotrichum sublineolum Henn.) resistance and agronomic traits

Journal of Phytopathology, Sep 24, 2019

Sorghum (Sorghum bicolor [L.] Moench, 2n = 2x=20) is the fifth most important cereal crop globall... more Sorghum (Sorghum bicolor [L.] Moench, 2n = 2x=20) is the fifth most important cereal crop globally. Sorghum anthracnose, caused by the fungal pathogen Colletotrichum sublineolum [Henn.] Sacc. & Trotter (formerly known as C. graminicola [Ces.] G.W. Wilson), is the major yield-limiting disease in susceptible sorghum varieties (Li, Zhu, Liu,

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Groundnut production constraints, farming systems, and farmer-preferred traits in Tanzania

Journal of Crop Improvement, Oct 14, 2018

Groundnut (Arachis hypogaea L.) production in Tanzania is affected by a multitude of biotic and a... more Groundnut (Arachis hypogaea L.) production in Tanzania is affected by a multitude of biotic and abiotic stresses and socioeconomic constraints. The objective of this study was to document the groundnut farmers' major production constraints, farming systems, and varietal trait preferences in selected agroecologies of Tanzania. A participatory rural appraisal study was conducted in three groundnut-producing zones: Lake, Central, and Southern. Data were collected from 170 groundnut farmers using a semistructured questionnaire, focus group discussions, and field observations. The production constraints were mainly diseases and pests, which were reported by 87.7% and 84.9% of respondents, respectively. Groundnut rust, caused by Puccinia arachidis Speg, was the major cause of yield reduction, as reported by 30% of the respondents. Drought stress and nonavailability of seed of improved varieties were other important constraints, as reported by 83.9% and 76.1% of the respondents, respectively. Groundnut agronomic attributes preferred by farmers were as follows: high yield (reported by 78.4% of respondents), disease resistance (71.2%), early maturity (66%), drought tolerance (63.0%), and pest resistance (63%). Medium-tolarge grain size (reported by 62.6% of respondents) and tan and red seed color (59.2%) were the main farmer-and market-preferred groundnut seed quality traits. Groundnut variety development programs should therefore address the above constraints and farmer-preferred traits for sustainable groundnut production and productivity in Tanzania.

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Gene action controlling yield and yield-related traits among tef (Eragrostis tef [Zucc.] Trotter) populations under drought-stressed and nonstressed conditions

Plant Breeding, Jun 25, 2018

This study was aimed to determine gene action for grain yield and yield-related traits of newly d... more This study was aimed to determine gene action for grain yield and yield-related traits of newly developed tef populations under drought-stressed and nonstressed conditions to improve drought tolerance. Ten crosses, along with the parents, were evaluated in the F 2 generation under drought-stressed conditions at Hastebo and Adigdad sites in 2015 and Dura site in 2016 and under nonstressed conditions at Dura site in 2016. Additive gene action predominantly controlled the inheritance of the grain yield and majority of the yield-related traits under drought-stressed and nonstressed conditions. Under both test conditions, the genotypes DZ-Cr-387 and 9415 were the best general combiners for increased grain yield and morphological traits. Conversely, genotype 222076 was the best general combiner for reduced maturity period only. The selected parents are novel genetic materials for tef breeding programmes to improve grain yield and morphological traits with reduced days to maturity for drought tolerance breeding. The family of the cross DZ-Cr-387 9 222076 was selected for high grain yield and early maturity in both the drought-stressed and nonstressed environments.

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Appraisal of farmers wheat production constraints and breeding priorities in rust prone agro-ecologies of Ethiopia

African Journal of Agricultural Research, Mar 23, 2017

Ethiopia is the second largest producer of wheat in sub-Saharan Africa although yields remain con... more Ethiopia is the second largest producer of wheat in sub-Saharan Africa although yields remain considerably below the global average due to several production constraints. The aim of the study was to identify the primary threats to wheat production, farmers' selection criteria for wheat varieties, and disease management practices with emphasis on wheat rusts in the Arsi, Bale and West Shewa administrative zones of Ethiopia. A total of 270 wheat growing households were interviewed in the three administrative zones in 2012. Participatory rural appraisal tools, a semi-structured questionnaire and focus group discussions were used to engage with the farmers. Main wheat production constraints were wheat rust diseases, the high costs of fertilizers, shortage of improved seeds and high seed prices. The most important traits that farmers sought in wheat varieties were disease resistance (27.8%) and high grain yield (24.8%). Owing to the limited availability of rusts resistant varieties, and the emergence of virulent pathotypes, fungicide application was the main disease management practice used by 60% of respondent farmers. To enhance wheat production and productivity in Ethiopia, it is important to develop rust resistant varieties considering farmers' preferences, promote access to wheat production inputs and strengthen seed multiplication and dissemination of improved varieties.

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Phenotypic characterization of diverse Bambara groundnut (Vigna subterranea [L.] Verdc.) germplasm collections through seed morphology

Genetic Resources and Crop Evolution, Apr 20, 2016

Bambara groundnut (Vigna subterranea [L.] Verdc.) is an important grain legume native to Africa. ... more Bambara groundnut (Vigna subterranea [L.] Verdc.) is an important grain legume native to Africa. Unlike other legumes, the crop has been largely neglected by science and is part of the socalled neglected and underutilized plant species of Africa. In Africa, farmers currently grow unimproved and heterogeneous landraces in seed mixtures that hold distinctive and divergent genetic attributes. The systematic selection of Bambara groundnut landraces into defined homogenous groups of seed morphotypes for effective breeding would boost crop productivity and quality, and improve food security. Systematic pre-breeding of Bambara groundnut is a starting point to enhance the productivity of the crop. The objective of this study was to characterize a wide range of germplasm of Bambara groundnut collections using seed morphology to classify and identify unique germplasm. Bambara groundnut seed collections (58 seed lots) from seven diverse geographic origins were phenotyped using visual technique to describe seed morphological features including: seed coat colour and pattern, seed eye colour and pattern and hilum colour and pattern. The study generated baseline seed morphology diversity information, and 353 different seed morphotypes of the crop were distinguished for field production of true to type lines and further genetic improvement.

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Maize production constraints, traits preference and current Striga control options in western Tanzania: farmers’ consultation and implications for breeding

Acta Agriculturae Scandinavica Section B-soil and Plant Science, Aug 12, 2019

Striga spp. severely affect maize yields in Tanzania causing yield losses varying from 20% to 100... more Striga spp. severely affect maize yields in Tanzania causing yield losses varying from 20% to 100%. The use of Striga resistant varieties is an economical and environmentally friendly option that can be easily adopted by smallholder farmers. Uptake of newly developed varieties would be high if the breeding process is inclusive and consultative to farmer preferred traits and preferences. The aim of this study was to identify farmers' maize production constraints, current Striga control options, trait preference and perceptions among smallholder farmers in western Tanzania. Surveys were conducted in four districts, namely Igunga, Shinyanga rural, Urambo and Uyui during the 2017/ 2018 cropping season. Data were collected from 324 farmers using a semi-structured questionnaire (166), focus group discussions (158) and field observations. The major maize production constraints reported by farmers were; drought (97.2%), Striga infestation (93.1%), insect pests in field (90.1%) and in stores (72.7%). The main Striga control options described by farmers across the studied districts were: hoe weeding, uprooting, manure application and crop rotation in descending order. Only 59% of the farmers used the seed of improved maize varieties of either hybrids or open-pollinated varieties (OPV) which are Striga susceptible and the remaining used home saved seed. A breeding programme aiming at improving maize varieties for Striga resistance, including farmers' preferred traits, should be designed and executed to control Striga infestations thus improving maize production, productivity and profitability in western Tanzania.

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Genetic characterisation of a Eucalyptus nitens base breeding population in South Africa

Southern forests, Aug 25, 2013

The measurement and statistical analysis of data from eight Eucalyptus nitens trials established ... more The measurement and statistical analysis of data from eight Eucalyptus nitens trials established in the summer rainfall forestry region of South Africa during the 1980s and 1990s, have enabled the characterisation of the Institute for Commercial Forestry's breeding population. Provenance testing showed that the more northerly New South Wales (Australia) Eucalyptus nitens provenances of Barren Mountain and Barrington Tops are distinctly better suited to the summer rainfall areas of South Africa than the southern New South Wales provenances and the Victorian provenance, Penny Saddle. Generally, the species was not badly affected by Coniothyrium canker. High Type B genetic correlations for all sites pairs, except one comparison, ranged from 0.75 to 0.99 for dbh, indicating very little, or no, genotype-environment interaction for diameter at 1 breast height for the genotypes tested in this study. Narrow sense heritability coefficients ranged from 0.01 to 0.34, indicating that the species generally exhibits sufficient breeding opportunity for improvement of diameter growth. High genetic correlations of greater than 0.90 between diameter measurements at 52 to 62 months after establishment and diameter measurements at 94 or 113 months were found, indicating that selections can be reliably made at five or six years. Predicted genetic gains were highest in the trials at Goedehoop and Arthur's Seat, with increases in diameter at breast height of 3.07 cm (17.1%) and 3.17 cm (20.7%), respectively, at full rotation.

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Genotype Selection for Grain Yield of Sorghum through Generalized Linear Mixed Model

Agronomy

The classical model only provides a correct analysis if all the effects are fixed. For experiment... more The classical model only provides a correct analysis if all the effects are fixed. For experiments that include fixed and random effects, the general linear mixed model is appropriate for handling the non-normal distributed response variables. The aim of this study is to perform the genotype selection through a generalized linear mixed model and identify the impact of treatment and the related traits on grain yield. The data were collected using a lattice square design and measured the phenotype traits of sorghum. The result of PCA was used as an input variable for the general linear mixed model. The data analysis was performed using a general linear mixed model with maximum likelihood methods to estimate the parameters of the model. The result showed that the grain yield had a gamma distribution and a treatment effect on grain yield. The first principal component was significant for grain yield. The variability of grain yield due to the random effects of replication within treatmen...

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Effect of pH on nutrient removal and crop production of hydroponic systems treating brewery effluent

Water Supply

The use of a crop to remove nutrients from brewery effluent and the influence of pH on these remo... more The use of a crop to remove nutrients from brewery effluent and the influence of pH on these removal rates was evaluated. Cabbage (Brassica oleracea) was grown in recirculating hydroponic systems fed with post-anaerobically digested brewery effluent (BE) either subject to pH adjustment (6.5–7.0) or unaltered pH (8.0–8.5). These were compared with cabbages grown in water only and in a inorganic fertiliser nutrient solution (NS). Hydroponic systems fed with pH adjusted BE removed significantly more nitrogen and phosphorus than systems fed with pH unadjusted BE (p < 0.05). The final weight of cabbages from the pH adjusted BE systems were 6.7 times greater than cabbages from the pH unadjusted BE systems, whereas pH adjustment had no influence on cabbage weight in the water-only and NS treatments. Anaerobically digested BE that is not pH adjusted is not a suitable water and nutrient source for the hydroponic production of cabbages. However, pH adjustment of BE renders it more suitable...

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Dose-response relationship of Beauveria bassiana (Balsamo) Vuillemin on Rhipicephalus microplus ticks

Background Isolation and optimization are the primary step in the development of fungal pathogens... more Background Isolation and optimization are the primary step in the development of fungal pathogens for biological control agents. In this study, three indigenous strains of Beauveria bassiana (Bb-27, Bb-40 and Bb-41) and one commercial strain (Eco-Bb) were tested for dose/response relationship of the fungus against Rhipicephalus microplus ticks. Results We used R. microplus larvae of 2 weeks of age, and exposed them to four conidial concentrations: 1x103, 3x105, 4x107, 3.2x108 conidia.mL− 1 of each strain. Water was used as a control. Larval mortality was significantly affected by the type of formulation. There was a positive relationship between the concentration of the formulation and mortality of the treated ticks. All the ticks treated with the formulation containing 3.2x108 conidia.mL− 1 resulted in high levels of mortality. Conclusions From this study, it can be concluded that, because of the diversity in the performance of B. bassiana strains, optimization of the formulation f...

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Trichoderma harzianum as a tool for reaching suitable growth and vegetation cover on mine tailings

Proceedings of the Sixth International Conference on Mine Closure, 2011

Rapid and efficient revegetation of mining landscapes is always a challenge. One of the main diff... more Rapid and efficient revegetation of mining landscapes is always a challenge. One of the main difficulties in revegetation is the amount of plants species which are able to establish and survive in the harsh conditions often associated with mining. Finding a suitable growth medium is the initial requirement for the plant to produce an appropriate vegetation cover. Fast growing plants with a good root system are of interest as they not only immobilise metals but also prevent erosion and soil compaction. For this reason, it is important for the phytoremediation biotechnologies to have a better understanding of the potential growth of different plant species. Recent publications have shown the potential interest of using grasses as the first stage of revegetation. The candidates should be fast growing and resist metal toxicity when planted on mine tailings. Many products have been registered as growth promoters. One of them, Eco-T, a fungal species (Trichoderma harzianum Rifai strain kd) is currently produced in South Africa and well accepted as a growth promoter. AgriSil K50 a silica based product is known to provide a regular supply of potassium to the plant.

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Proximate composition, cyanide contents, and particle size distribution of cassava flour from cassava varieties in Zambia

AIMS Agriculture and Food, 2019

The utilisation of cassava in the food industry is on the rise in Africa. However, information ab... more The utilisation of cassava in the food industry is on the rise in Africa. However, information about the quality traits of raw material derived from new cassava varieties is limited. Cassava flours processed from six cassava varieties (Bangweulu, Katobamputa, Mweru, Kariba, Kampolombo and Chila) were assessed for particle size distribution, dry matter, starch yields; proximate contents, cyanides and whiteness index. The variety effect was analysed. The moisture, protein, lipid, ash, and fibre contents were in the range 10.43-11.18, 1.21-1.87, 0.15-0.63, 1.21-1.78, and 0.03-0.60%, respectively. The average particle size distribution at D90 (250.44-334.34 μm) and D10 (35.56-48.52 μm) varied (p < 0.05) among varieties. The bulk and packed density ranged 0.40-0.47 and 0.62-0.67 g/cm 3 , respectively. Bulk density correlated positively (p < 0.05) with moisture content. The cassava root dry matter contents varied in the range 40.04-47.25%, and correlated negatively with lipid (p < 0.01), ash content (p < 0.05) and positively with fibre (p < 0.01). Starch yield ranged between 20.76 and 28.31%. The cassava cyanide contents were in the range 23.60-238.12 and 8.62-15.48 mg HCN/kg for roots and flours, respectively. The cyanide reduction was in the range 60.76-93.86%. Degrees of lightness (L*) were in the range between 93.65 and 94.55, yellowness (b*) 6.52-8.15 with greenness in the range −0.03 to 0.44. The whiteness index of flours was in the range 89.90 to 91.46. Whiteness index negatively correlated with fibre content (p < 0.01). The quality traits varied among the cassava varieties, and source of variations were due to differences in flour particle size, fibre and ash contents.

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Determination of productivity, rooting and nutrient profile of Acacia mearnsii (black wattle) hedge plants

Australian Forestry, Jul 11, 2023

Correlation and path-coefficient analyses of root yield and related traits among selected sweetpotato genotypes

The South African Journal of Plant and Soil, Nov 27, 2017

Integrated pest management in Southern Africa

Routledge eBooks, Nov 27, 2019

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Adoption and Promotion of Resilient Crops for Climate Risk Mitigation and Import Substitution: A Case Analysis of Cassava for South African Agriculture

Frontiers in sustainable food systems, Apr 15, 2021

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Isolation of yeast and Bacillus strains for postharvest control of Penicillium digitatum on citrus fruits in South Africa

Genetic analysis of dual-purpose sweetpotato genotypes using simple sequence repeat markers and phenotypic traits

Journal of Crop Improvement, Apr 1, 2021

Evaluation of candidate orange-fleshed sweetpotato clones for nutritional traits

Acta Agriculturae Scandinavica Section B-soil and Plant Science, May 12, 2017

Genotype-by-environment interaction for dual-purpose traits in sweetpotato

Journal of Crop Improvement, Jun 18, 2020

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Assessment of sorghum genetic resources of Ethiopia for anthracnose ( Colletotrichum sublineolum Henn.) resistance and agronomic traits

Journal of Phytopathology, Sep 24, 2019

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Groundnut production constraints, farming systems, and farmer-preferred traits in Tanzania

Journal of Crop Improvement, Oct 14, 2018

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Gene action controlling yield and yield-related traits among tef (Eragrostis tef [Zucc.] Trotter) populations under drought-stressed and nonstressed conditions

Plant Breeding, Jun 25, 2018

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Appraisal of farmers wheat production constraints and breeding priorities in rust prone agro-ecologies of Ethiopia

African Journal of Agricultural Research, Mar 23, 2017

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Phenotypic characterization of diverse Bambara groundnut (Vigna subterranea [L.] Verdc.) germplasm collections through seed morphology

Genetic Resources and Crop Evolution, Apr 20, 2016

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Maize production constraints, traits preference and current Striga control options in western Tanzania: farmers’ consultation and implications for breeding

Acta Agriculturae Scandinavica Section B-soil and Plant Science, Aug 12, 2019

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Genetic characterisation of a Eucalyptus nitens base breeding population in South Africa

Southern forests, Aug 25, 2013

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Genotype Selection for Grain Yield of Sorghum through Generalized Linear Mixed Model

Agronomy

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Effect of pH on nutrient removal and crop production of hydroponic systems treating brewery effluent

Water Supply

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Dose-response relationship of Beauveria bassiana (Balsamo) Vuillemin on Rhipicephalus microplus ticks

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Trichoderma harzianum as a tool for reaching suitable growth and vegetation cover on mine tailings

Proceedings of the Sixth International Conference on Mine Closure, 2011

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Proximate composition, cyanide contents, and particle size distribution of cassava flour from cassava varieties in Zambia

AIMS Agriculture and Food, 2019

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Development of transgenic baby marrow (Cucurbita pepo l.) Plants with broad resistance to potyviruses occurring in KwaZulu-Natal.

by Jacques D Ibaba and Mark Laing

Plant viruses are a major limiting factor of cucurbit production in the Republic of South Africa ... more Plant viruses are a major limiting factor of cucurbit production in the Republic of South Africa (RSA). Current methods of controlling virus diseases infecting cucurbits are not very effective thus necessitating the need to look for alternative approaches. The aim of this study was to develop baby marrow (Cucurbita pepo L.) plants with multiple resistance to the common Potyviruses infecting cucurbits in the province of KwaZulu-Natal (KZN). Surveys were conducted throughout KZN during the 2011 - 2013 growing seasons to identify cucurbit-infecting viruses. Cucumber mosaic virus (CMV), Beet pseudo yellows virus (BPYV), Zucchini yellows virus (ZYMV), Morrocan watermelon mosaic virus (MWMV), Pepo aphid-borne yellows virus (PABYV) and a distinct tentative species in the genus Potyvirus from the Papaya ringspot virus (PRSV) cluster were the viruses identified using double antibody sandwich enzyme-linked immunosorbent assay and reverse transcription polymerase chain reaction (RT-PCR) and characterized using phylogenetic analyses. Portions of the coat protein gene of the three potyviruses detected in the survey (MWMV, ZYMV and the tentative Potyvirus) were incorporated into a gene construct that was used to transform baby marrow cotyledon explants. Agrobacterium-mediated transformation was used. Resultant putative transgenic baby marrow plants were screened by PCR and resistance was evaluated by challenging plants with inoculum made from a mixture of the selected three Potyviruses. Southern and Northern blot hybridization are still to be performed on putative transgenic plants to confirm the nature of the resistance which is expected to be via post-transcriptional gene silencing (PTGS). The findings of this study will contribute positively to strategies that effectively manage virus diseases in cucurbits in RSA.

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