Mark D. Laing

• PhD, Plant Pathology, University of Natal
• Professor Emeritus at University of KwaZulu-Natal

Wheat (Triticum aestivum L. (2n = 6x = 42; AABBDD)) is a commodity crop serving diverse value chains worldwide. However, drought stress and poor soil health are major causes of a yield gap in wheat production. Silicon (Si) fertiliser application with drought-adapted wheat cultivars may enhance wheat productivity. This study aimed to examine the imp...

Tannins are the major extractable component of black wattle (Acacia Mearnsii de Wild) bark. In a wattle factory, extracted tannin levels are one of several quality parameters (Extraction efficiency and insoluble content are some of the other parameters) that are monitored, typically using a modified Soxhlet/ reflux extraction method. However, this...

Maize (Zea mays L.) plays a critical role in smallholder food security in Ethiopia. Its production is rapidly increasing to the Highlands of Ethiopia where it has been a minor crop in the past. This study aimed to assess the magnitude and production systems of Highland maize, farmers’ production constraints, and their implications for the adoption...

Acacia mearnsii De Wild (black wattle) is one of the most important forestry crops in South Africa. The bark of this species contains high-quality tannins, while its wood is used for wood chips, charcoal and mining timber. One of the main problems faced by black wattle farmers is frost damage, thus there is an urgent need to develop frost-tolerant...

A ield study was carried out to evaluate the ef icacy of pendimethalin 500 EC (trade name: Pendimight ®) and oxy luorfen 240 EC (trade name: Harris ®) to control weeds in direct-seeded onion (Allium cepa L.). Pendimethalin and oxy luorfen were applied solely at reduced rates (1.35 and 0.17 kg a.i. ha-1), and at the recommended rates (1.8 and 0.25 k...

Biocontrol of Storage Grain Pests

Identification of maize germplasm with dual resistance to Striga hermonthica (Sh) and S. asiatica (Sa), could lead to the development of cultivars with stable resistance. 130 tropical and sub-tropical maize germplasms, including checks, were evaluated in a controlled environment for their reaction to Sh and Sa infestations using a 13 × 10 alpha lat...

Although chemical control remains a key method to control targeted pests, a controversy has surfaced regarding the use and abuse of pesticides. The diversity of pests found in cotton requires serious control, mostly with pesticides, which negatively impact natural enemies and the environment. The continuous use of synthetic chemicals to protect cro...

The breeding stages of a clonally propagated crop entails several steps and can take more than five years from hybridisation till cultivar release. The Accelerated Breeding Scheme (ABS) in sweetpotato relies on the use of multiple locations at the early breeding stages to reduce the years required for field evaluation. The aim of the study was to s...

Low-temperature stress is an important limiting factor affecting citrus growth and fruit yields. Therefore, increasing citrus cold stress tolerance may enhance the growth, yield, and quality of citrus production in marginal areas. The objective of this study was to determine the efficacy of silicon (Si) fertilizer application on cold-tolerance enha...

The present study is to investigate the level of pesticide residues in soil and water samples from the Gezira Scheme. The results revealed the presence of OCs (lindane, o-p’ DDT, endrin, aldrin, dieldrin, α-endosulfan), OPs (profenofos, malathion, chlorpyrifos), and the plant growth regulator (ethephon) in soil and water samples. Lindane, o-p’ DDT,...

Biocontrol of Tuta absoluta by using Entomopathogenic Nematodes

Cotton is one of the essential cash crops; however, several factors, such as low yields and pest and disease infestations, affect the production. In South Africa, cotton production has increased among small-scale farmers since the late 1990s. Although the crop is not new to South African farmers, no recent information reflects the current status of...

Identification of maize germplasm with dual resistance to Striga hermonthica (Sh) and S. asiatica (Sa) , could lead to the development of cultivars with stable resistance. 130 tropical and sub-tropical maize germplasms were evaluated in a controlled environment for their reaction to Sh and Sa infestations using a 13x10 alpha lattice design with two...

The 2030 Agenda for Sustainable Development Goals of the United Nations puts forward a transformational vision to cope with food security, nutrition, and health challenges, in which sweet potato can play an important role. Globally, sweet potato production is valued at $53.83 billion. The Agricultural Research Council of South Africa (ARC) sweet po...

The tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is a devastating pest worldwide affecting tomato production. The efficacy of soil treatments of the entomopathogenic nematode (EPN) Heterorhabditis indica strains NOAC.N1 and NOAC.N2 were determined against the fourth instar larvae (L4 larvae) and pupae at one, three, and...

Drought is one of the major constraints of wheat production, especially in rainfed wheat production systems. The objective of this study was to evaluate the effects of different silicon fertilizer formulations on the agronomic performance of diverse wheat genotypes under drought-stressed conditions. Twenty wheat genotypes were evaluated in field an...

The authors would like to make the following corrections about the published paper [...]

It was interested presentation at Ethiopian Statistical Association (ESA) in July, 2023.

It was very interesting presentation at the Ethiopian Statistical Association in July 2023

Cassava (Manihot esculenta Crantz) is an important root crop worldwide. It is adapted to a wide range of environmental conditions, exhibiting differential genotypic responses to varying environmental conditions. The objectives of this study were: (1) to examine the effect of genotype, environment and genotype × environment interaction (GEI) on fres...

The potential yield of maize (Zea mays L.) and other major crops is curtailed by several biotic, abiotic, and socio-economic constraints. Parasitic weeds, Striga spp., are major constraints to cereal and legume crop production in sub-Saharan Africa (SSA). Yield losses reaching 100% are reported in maize under severe Striga infestation. Breeding for...

Maize cultivars with resistance to Striga spp. and compatible to Fusarium oxysporum f.sp. strigae ( FOS ) are an economical, sustainable and environmentally Striga control option. This study's objective was to determine the type and magnitude of gene action controlling grain yield and yield‐related components, Striga resistance, FOS compatibility a...

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 id...

Parasitic Striga weeds severely damage cereal crops in sub‐Saharan Africa (SSA), leading to yield losses in susceptible varieties. A range of Striga control methods are commonly recommended, including cultural practices, chemical herbicides, biological control agents, and host resistance, either as solo treatments or in combinations of these approa...

Stable and sustainable food systems are required to meet the increasing global food demands due to climate change, global population pressure, urbanization and life style changes. Underutilized legume crop species such as Bambara groundnut (Vigna subterranea [L.] Verdc.) have exceptional nutritional value and genetic plasticity to be cultivated in...

Tef is the most widely grown and consumed crop in Ethiopia. The crop is currently gaining growing popularity worldwide as nutritious and gluten free cereal crop. Al-toxicity is one of the factors that limit expansion of the crop worldwide. The aims of this study were to adapt hydroponic system as a phenotyping platform for Al-tolerance studies in t...

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 and nutrient security. This study was conducted to evaluate the performance and adaptability of exotic ca...

A naturally ventilated solar-venturi dryer (NSD) was constructed using locally available materials to improve the quality of dry sweet potato slices (SPS) for small to medium scale farmers. The study investigated the efficiency of the NSD to reduce relative humidity (RH), solar radiation and temperature effect on firmness and color of dried SPS. Th...

Knowledge of fall armyworm (FAW) (Spodoptera frugiperda J.E. Smith) rearing, infestation and development and precision screening protocols are preconditions for the successful introgression of resistance genes into farmer-preferred varieties. We aimed to determine FAW developmental stages, screen tropical maize and select resistant lines under cont...

Knowledge of genetic interrelationships and grouping among pigeonpea germplasm collections is fundamental to selecting breeding parents with unique genetic constitutions. The objectives of this study were to assess the genetic diversity and genetic grouping present among 81 pigeonpea genotypes collected from Malawi, Tanzania and Kenya using 4122 si...

Short-term and long-term evaluation studies were conducted against Ephestia cautella on rice grains, using Beauveria bassiana Strain MS-8 formulated in various doses of kaolin as an active carrier. In the short-term study (45 days), a fixed dose of 0.03 g conidia kg−1 of grain of Strain MS-8 was formulated in kaolin at doses of 0.3, 0.5, 1, and 2 g...

Cotton is one of the most valuable materials in the world, popularly used in the clothing industry and other products. However, its production is limited by the high infestation of insect pests. A study was conducted to evaluate the effects of different biopesticides on the control of the African bollworm (Helicoverpa armigera) under cotton field c...

Knowledge of the genetic diversity and genetic relationship is important in crop improvement. The objective of this study was to determine the genetic diversity of 31 sweetpotato genotypes and furthermore to select distantly related individuals for breeding of superior parental clones. The genotypes (sourced from the Agricultural Research Council,...

Wheat (Triticum aestivum L.) is traditionally cultivated under drought-affected and low-input agro-ecologies in sub-Saharan Africa, including Ethiopia. Wheat productivity in these agro-systems is considerably low (50%) planted wheat in early July using the broadcasting method. Their land was of medium fertility, and the application of inorganic fer...

Understanding demographic structures, production constraints, and trait preferences is essential for setting up crop breeding goals and enhancing adoption strategies for new varieties. The objective of this study was to document the sorghum (Sorghum bicolor L. Moench) production constraints and preferred sorghum traits to guide breeding in Sierra L...

Sorghum hybrids can provide enhanced bioethanol yield if genetically complementary parents and progenies are developed using efficient crossing and selection methods. The objective of this study was to determine the combining ability of sweet stem sorghum genotypes, and assess heterosis among F1 hybrids for ethanol production and associated traits....

Background: Cowpea [Vigna unguiculata (L.) Walp.] in Zambia is a valuable source of cheap protein, complement to the food systems and value chains in rural and urban areas despite the low productivity. This study aimed to document the present level of cowpea production, identify constraints affecting cowpea production among smallholder farmers and...

The current study evaluated the bio-control activity of Sudanese isolates of entomopathogenic-fungi against 3 rd larval instars of Khapra beetle (Trogoderma granarium) (Everts) in Sudan and morphologically and molecularly characterized the virulent isolates. Fungi were isolated using Galleria-baiting method and tested against the larvae using immer...

Cotton (Gossypium hirsutum L.) is the most produced natural fibre worldwide, and it contributes significantly to the economy of almost 80 cotton-producing countries. Given the high pest infestation, huge amounts of insecticides have been used in cotton production. However, this has resulted in the development of resistance from primary cotton pests...

The drying of agricultural produce is an important food preservation measure. However, high energy requirements for drying, limited access to energy sources, small-medium scale farmers experience high post-harvest losses of their produce. Therefore, there is a need to develop and optimize low-cost food preservation technologies. In this study, four...

Cotton (Gossypium hirsutum L.) is one of the essential fibre crops. However, several factors affect production, including low yields, high input costs, pests, and weeds infestations. Biopesticides can play a vital role in the integrated programme to address the challenges that limit production and reduce the profits for cotton farmers. This thesis...

Several studies have demonstrated Si absorption in monocotyledonous and dicotyledonous species. Regarding Si uptake, studies in monocotyledons have identified Si deposition around the cell wall, cuticle layer bulliform cells, silica cells and endodermal cells. In previous studies with different citrus species there was evidence of Si uptake, howeve...

Formulations of the entomopathogenic fungus Beauveria bassiana (Hypocreales: Cordycipitaceae) were tested under field conditions against the bovine tick adults Rhipicephalus microplus (Acari: Ixodidae). Formulations were prepared for each fungal isolate consisting of 10⁸ conidia.mL⁻¹, 10% avocado oil and either of Ballista® or Break-thru® as an adj...

Combining ability analysis is fundamental in breeding programs to select desirable parents and progenies. The objectives of this study were to determine the combining ability effects, and gene action controlling agronomic traits and resistance to Fusarium wilt (FW) caused by Fusarium udum Butler in pigeonpea [Cajanus cajan (L.) Millspaugh]. Twenty-...

A 22-m 3 residential room was converted to a seed storage facility by retrofitting a solar collector on the roof. Three different chimney sizes of diameter and height of 200 mm x 3.6 m, 200 mm x 4.8 m, 300 mm x 3.6 m and 300 mm x 4.8 m were investigated to determine the best size of the chimney to be used for ventilation in a storage facility. The...

Beauveria bassiana (Hypocreales: Cordycipitaceae) is an entomopathogenic fungus that has shown promising results as a biocontrol agent of ticks. Locally isolated B. bassiana are better acclimatised to the natural conditions of their geographical origin; therefore, they are essential in developing effective biocontrol agents for ticks. The current s...

Crop improvement depends on availability of genetic variation. However, recombination during sexual reproduction may be inadequate or slow for successful crop improvement. Ethylmethanesulphonate (EMS) is widely used to induce mutations and create new genetic variation in plants. The objective of this study was to determine optimum dosage and treatm...

Safe drinking water and sanitation are very important for the survival of human life. With the rapid proliferation of industries, growth in population and different forms of pollution, i.e. in water, air, soil and sediments, the living environment and the ecosystem is constantly polluted. In this context, integrating different water resources for e...

Finger millet (Eleusine coracana (L.) Gaertn) is a highly nutritious crop, predominantly grown in the semi-arid tropics of the world. Finger millet has a niche market opportunity due to its human health benefits and being rich in calcium, iron and dietary fiber and gluten-free. Ethiopia is the center of the genetic diversity of the crop. However, t...

Selecting genetically diverse and complementary parental lines and superior crosses are pre-requisites in developing improved cultivars. The objectives of this study were to determine the combining ability effects and gene action conditioning rice yellow mottle virus disease (RYMVD) resistance and agronomic traits in rice (Oryza sativa L.). Ten par...

Pigeonpea Cajanus cajan (L.) Millsp. is the most important legume cash crop grown in Malawi. However, productivity is low due to biotic and abiotic stresses and socioeconomic constraints. The objectives of this study were to determine farmers’ perceived constraints to pigeonpea production and to identify the varieties and traits preferred by farmer...

This study aimed to select desirable parents and single-cross hybrids with partial FAW resistance and suitable agronomic traits for effective (FAW) (Spodoptera frugiperda Lepidoptera: Noctuidae J.E. Smith) resistance pre-breeding and breeding programs in Zambia and related agro-ecologies. A line × tester mating design was used to generate 60 experi...

This paper reviews the threat of citrus pathogens during citrus production, with a focus on two pre-harvest diseases, citrus leaf spot, caused by Alternaria alternata (Fr.) Keissl. (1912) and brown rot, caused by Phytophthora citrophthora (R.E. Sm. and E.H. Sm.) Leonian, (1906) as well as green and blue mold post-harvest disease, caused by Penicill...

Sorghum bicolor L. Moench (Poaceae) is a cereal crop grown worldwide and playing an important role in human nutrition as well as feed for livestock. Lepidopteran stem borers are the most economically important insect pests that affect sorghum production and their management relies on the use of insecticide chemicals that have adverse effects on hum...

The production and quality of wheat are affected by abiotic constraints including water stress and soil nutrient deficiencies. It is imperative to develop drought-tolerant wheat varieties with high yield potential and enhanced grain protein content for food security. Silicon (Si) is important for plant growth and development but its role in abiotic...

The current study evaluated the efficacy of indigenous isolates of entomopathogenic fungi against the third larval instar of tomato leaf miner (Tuta absoluta Meirick; Lepidoptera: Gelechiidae). Four virulent isolates were subject to morphological and molecular identification and they were identified as; Beauveria bassiana isolate Hammad-R7 (Sudan)...

The fall armyworm (FAW) (Spodoptera frugiperda J.E. Smith) is an invasive pest of maize, as well as other important cereals and vegetables, threatening food systems and biodiversity in Sub-Saharan Africa. This study aimed to assess the outbreaks of the FAW, farmers’ perceived production constraints, and coping strategies in maize production in Zamb...

The performance of a solar energy-assisted seed storage room was evaluated through an ordinary 22-m 3 room that was retrofitted with a solar collector, inlets and chimney. The structure was made of a solar collector to heat the ambient air before entering the chimney. The chimney circulated the air inside the structure and inlets. To compare the pe...

The performance of a solar energy-assisted seed storage room was evaluated through an ordinary 22-m 3 room that was retrofitted with a solar collector, inlets and chimney. The structure was made of a solar collector to heat the ambient air before entering the chimney. The chimney circulated the air inside the structure and inlets. To compare the pe...

The narrow genetic variation for drought adaptive traits and biomass allocation in wheat ( Triticum aestivum L.) presents a major bottleneck for breeding. Induced mutagenesis creates genetic variation and complements conventional breeding for drought tolerance improvement. The aims of this study were to induce mutations in wheat genotype LM43 using...

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. Re...

Drought is a major cause of reduced yields in dryland wheat production. This study aimed to determine the combining ability effects of selected bread wheat genotypes (Triticum aestivum L.) for yield and yield-related traits. Eight parental lines were selected and crossed using a half-diallel mating design. The parents and 28 crosses were evaluated...

Pearl millet (Pennisetum glaucum) is a staple food crop in Burkina Faso that is widely grown in the Sahelian and Sudano-Sahelian zones, characterised by poor soil conditions and erratic rainfall, and high temperatures. The objective of this study was to document farmers’ perceptions of the prevailing constraints affecting pearl millet production an...

Drought is one of the major constraints to wheat production and productivity globally. Developing drought-adapted wheat cultivars is paramount to increase wheat productivity under variable rainfall conditions. Understanding the genetic variability and trait association is key to the development of improved wheat cultivars. The objective of this stu...

Background: Bread wheat (Triticum aestivum L.) is a valuable commodity crop for local, regional and global markets. In Ethiopia, wheat ranks third after maize (Zea mays L.) and tef (Eragrostis tef Zucc.) in terms of total production, and fourth after maize, tef and sorghum (Sorghum bicolor L.) in areas of cultivation. The major wheat-producing area...

A new generation of chemical hybridization agents (CHAs) or gametocides has shown potential to induce male sterility in predominantly self-fertilizing crops, including sorghum (Sorghum bicolor [L.] Moench). There is a lack of information on the relative efficacy of the various available CHAs for large-scale application in plant breeding programs. T...

The significant role of agriculture in the transformation of emerging economies has been well founded in the literature. This has contributed to the implementation of a number of intervention programs aimed at improving agricultural productivity and, subsequently, household welfare. However, the magnitude of the impact of adoption of any innovation...

Sweetpotato improvement is influenced by selection of superior and best combiner parents with desirable traits. This study determined the genetic control of root nutrients: protein, β-carotene, starch, simple sugars and selected minerals. Two heterotic groups of five parents were crossed using a North Carolina II mating design to generate 25 full-s...

As part of the Green Revolution, plant breeding programmes such as the African Centre for Crop Improvement have trained scientists to breed crop varieties in Africa to address the challenges of low productivity. However, exposure to and adoption of these varieties is somewhat modest, and there is also a scarcity of empirical studies on the drivers...

Striga species cause significant yield loss in maize varying from 20 to 100%. The aim of the present study was to screen and identify maize genotypes with partial resistance to S. hermonthica (Sh) and S. asiatica (Sa) and compatible with Fusarium oxysporum f. sp. strigae (FOS), a biocontrol agent. Fifty-six maize genotypes were evaluated for resist...

Despite Rwanda's impressive economic success over the last decade, household food insecurity persists, particularly in rural areas. Empirical evidence is therefore deemed necessary to inform policies addressing food insecurity, hunger and poverty in general. This study examines household food security and its determinants in the rural areas of Sout...

Breeding new and high performing cultivars with market‐preferred traits take more than 10 years in the absence of an integrated pre‐breeding programme. During the early phases of breeding a significant amount of time, space and resources are invested in the selection and genetic advancement stages after initial crosses are performed with parental g...

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 an...

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 north-eastern p...

The aim of this study was to assess the extent of genetic diversity among and within tef populations collected from acid-affected soils in Ethiopia, and to test the cross-amplification of markers linked to Al-toxicity tolerance in other cereals. Forty-two tef genotypes were studied using 33 highly polymorphic SSRs. About 55% of the amplified putati...

Rice (Oryza species) is a commercial crop worldwide. Across Africa, the potential yield and quality of rice is diminished by a lack of high performance, locally adapted varieties, and the impact of rice yellow mottle virus (RYMV). The objective of this study was to assess the performance of a diverse collection of rice germplasm for RYMV resistance...

Genotype-by-environment interaction (GEI) analysis is fundamental in crop improvement programmes to guide selection and for recommendation of high performing and stable genotypes for breeding or production. The objectives of this study were to quantify the GEI effects and determine grain yield stability among diverse pigeonpea genotypes to select c...

Cotton is a major fibre crop grown in South Africa; and is subjected to pest attacks, which reduce its yield and profitability for farmers. Field trials were conducted in 2017 and 2018 to evaluate three biopesticides, namely, Eco-Bb®, Bb endophyte, and Metarhizium rileyi in comparison with the insecticides Chlorpyrifos® 480 EC, Karate® EC, and Band...