Environmentally safe methods for controlling plant-parasitic nematodes

Entomo-Pathogenic Nematode: An Effective and Eco-Friendly Alternative to Synthetic Pesticides. A Review

EPNs are increasingly used in Africa for managing key agricultural pests due to their effectiveness against banana weevils, fall armyworm, sweet potato weevils, and white grubs, but the key challenges include, temperature sensitivity and farmer adoption, however, ongoing research and local production are improving accessibility.

Sustainable Control Strategies for Thrips in Agricultural Crops: A Review

Sustainable farming faces an ongoing challenge from thrips, which are widespread agricultural pests that cause severe crop damage and spread harmful plant viruses. The overuse of chemical pesticides has backfired, leading to pest resistance, leaving toxic residues in the soil, and harming beneficial organisms, highlighting the need for eco-friendly alternatives for thrips management. Using biological controls offers a reliable path forward by capitalising on the natural interaction between predatory insects and plant-derived compounds. Beneficial organisms, such as Amblyseius swirskii (predatory mites) and minute pirate bugs, work alongside a variety of parasitoids to control thrips populations naturally. Furthermore, microscopic allies such as beneficial nematodes and specialised fungi (Beauveria bassiana and Metarhizium anisopliae) can be deployed to target pests at vulnerable points in their life cycles. Turning to botanical sprays, such as tobacco and neem-derived azadirachtin, also allows farmers to reduce dependency on synthetic chemical treatment. Combining these biological agents and botanical extracts into a unified Integrated Pest Management (IPM) model helps growers protect their crop yields, reduce chemical footprints, and build long-term agricultural resilience.

“Current Applications of Trichoderma in Agriculture Biocontrol of Fungal Pathogens And Enhancement of Plant Growth”

Filamentous fungi of the genus Trichoderma, commonly found in the rhizosphere, are a prevalent component of various soil ecosystem mycobiomes and are known for their ability to colonize plant roots. Understanding Trichoderma's characteristics, including its metabolic activity and interactions with plants and other microorganisms, is crucial for its effective application in agriculture. Interest in Trichoderma is growing due to its direct and indirect biocontrol capabilities against a wide spectrum of soil-borne phytopathogens. These fungi employ a range of complex mechanisms, such as mycoparasitism, degradation of pathogen cell walls, competition for nutrients and space, and activation of plant defence responses. Given the continuous threat posed to plants by various pathogens, particularly filamentous fungi, and the increasing resistance of these pathogens to chemical pesticides, there is a pressing need to develop alternative biological protection strategies. Among non-pathogenic microorganisms, Trichoderma stands out as a promising candidate for sustainable agricultural practices due to its extensive biofertilization and bio stimulatory properties. Most Trichoderma species function as plant growth-promoting fungi, capable of producing phytohormones and the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase. This review consolidates current knowledge on the role of Trichoderma, emphasizing its significance in promoting plant growth and its effectiveness in the biocontrol of fungal phytopathogens.

Harnessing Beneficial Bacteria for the Sustainable Management of Plant Viral Diseases

Conidia, enzymes and metabolites of Purpureocillium lilacinum Coad 4015 for the control of nematodes and insect pests: laboratory and field studies

Insect pests and plant-parasitic nematodes cause significant yield losses in agriculture, and the use of mycoparasitic fungi for their control has been increasing. However, a limited range of fungi has proven activity against these organisms, reinforcing the need to evaluate new strains and species with potential for biological control. This thesis aimed to characterize and evaluate the potential of a new strain of Purpureocillium lilacinum (COAD 4015) as a multi-target biological control agent, focusing on the management of nematodes and insect pests of agricultural importance. In Chapter 2, the strain was tested for the control of root-knot nematodes of the genus Meloidogyne in tomato crops. The application of conidia at different concentrations significantly reduced the number of eggs and juveniles in the soil and roots, in addition to promoting plant growth. The absence of fungal growth at 36°C indicated low risk to human health, reinforcing its safety for agricultural use. In Chapter 3, the efficacy of P. lilacinum was evaluated for the field control of the corn leafhopper (Dalbulus maidis). Two trials were conducted: one under commercial field conditions and another in a controlled experimental setting. The application of the fungus with an oil-based adjuvant improved conidial adhesion to the insect’s cuticle, overcoming natural barriers such as brochosomes, and resulted in population reduction of the pest, as well as a significant increase in maize grain yield. In Chapter 4, the pathogenicity of conidia, enzymes, and metabolites was investigated against D. maidis, Tenebrio molitor, and four lepidopteran pest species. The results indicated low overall pathogenicity, with moderate effects observed only in Rachiplusia nu (enzymes) and marginal response in Spodoptera frugiperda. Notably, the addition of P. lilacinum to the chemical insecticide acephate (active ingredient of the commercial product Acefato®) resulted in a 50% reduction in D. maidis mortality compared to acephate alone, suggesting a possible negative interaction between treatments. Overall, the findings position P. lilacinum COAD 4015 as a promising candidate for integrated pest and nematode management, with potential for safe and effective formulations, provided its compatibility with chemical products is carefully evaluated. Keywords: Meloidogyne; Dalbulus maidis; Spodoptera frugiperda;Rachiplusia nu; Chrysodeixis includens; Helicoverpa armigera

Pesticide-Induced Decline of Soil Arthropods: Ecological Consequences and Implications for Sustainable Agriculture

Pesticides comprise both naturally derived and synthetically manufactured compounds extensively employed to control insects, weeds, fungi, rodents, nematodes, and other agricultural pests. Their widespread application has significantly enhanced crop productivity and food security; however, indiscriminate use has resulted in serious environmental and public health concerns. Owing to their toxic nature, pesticides can adversely affect living organisms, and the World Health Organization (WHO) classifies these compounds according to their potential health hazards. This article provides a comprehensive review of pesticides' global distribution, classification, applications, and environmental effects. It summarizes the available literature on pesticide classification based on source, chemical composition, mode of action, target organisms, and toxicity. Furthermore, the review discusses the detrimental effects of pesticide residues on terrestrial and aquatic ecosystems, soil and water quality, plant physiology, metabolism, defence mechanisms, genotypic and phenotypic characteristics, and human health, including their association with genetic alterations, carcinogenesis, allergic disorders, and respiratory diseases. Eco-friendly approaches for pesticide remediation, such as bacterial degradation, mycoremediation, phytoremediation, and microalgae-based bioremediation, are highlighted. These biological systems utilize diverse catabolic enzymes to degrade pesticide residues and facilitate environmental detoxification. The review also emphasizes the need to identify efficient microbial strains, novel degradative genes, and advanced biotechnological strategies to achieve sustainable pesticide waste management.