Fungal Infestation Research Articles

Applications of dry chain technology to maintain high seed viability in tropical climates.

Seed storage life in tropical areas is shortened by high humidity and temperature and the general inaccessibility to dehumidifying and refrigeration systems, resulting in rapid decreases in seed viability in storage as well as a high incidence of fungal and insect infestations. The dry chain, based on rapid and deep drying of seeds after harvest followed by packaging in moisture-proof containers, has been proposed as an effective method to maintain seed quality during medium-term storage in humid climates, even without refrigeration. In addition, seed drying with zeolite drying beads can be more effective and economical than sun or heated-air drying under these warm, humid conditions. In this paper, we review recent published literature regarding the dry chain, considering different crop species, storage environments and seed traits. In addition, we provide new original data on the application of dry chain methods and their implementation at larger scales in South Asia, Latin America and Pacific Island Countries. The clear conclusion is that the combination of reusable drying beads and waterproof storage containers enables the implementation of the dry chain in tropical climates, enhancing seed viability and quality in storage of many crop species. The dry chain approach can therefore significantly enhance seed security for farmers in many tropical countries. Finally, we propose actions and strategies that could guide further scaling-up implementation of this technology.

Study of Fungal Organisms Associated with Smoked and Dried Fish Sold in Awka Markets, Anambra State

Fungal contamination of fish is considered as the major cause of spoilage and it constitutes a significant public health problem. This study was carried out to determine the fungal organisms associated with smoked and dried fish samples: Scomber scombrus (Mackerel), Sardinella longiceps (Sardine), Oreochromis niloticus (Tilapia), Clarias gariepinus (catfish), Gadus morhua (Stock fish), Ethmalosa fimbriata (Bonga fish), and Citharinus citharus (Mangala) sold in Awka markets, Anambra State, Nigeria. A total of fifty (50) (25 smoked and 25 dried) fishes were obtained from three markets in Awka and examined microbiologically for viable fungal infestation using Potato Dextrose Agar (PDA) media. A total of 121 fungal organisms were isolated from 25 smoked and 25 dried fish samples and identified. The isolated fungi were Mucor spp, Aspergillus niger, Aspergillus flavus, Penicillium spp, Fusarium spp and Rhizopus spp. It was observed that all the fish samples harboured multiple fungal organisms. Aspergillus niger was the fungus with the highest mean fungal count of 9.00±5.568, followed by Mucor spp (8.00±1.732), while Aspergillus flavus was the lowest (3.67±1.528). In the dried fish samples, Gardus morhua (stock fish) had the highest infestation with fungi (1.08±1.083), while in smoked fish, Clarias gariepinus (catfish) had the highest infestation. The high level of fungal contamination can be attributed to poor handling of fish and the environment. Considering the danger to public health, food and safety authorities should intensify their monitoring efforts towards controlling fish contamination, and fish sellers should also be sensitized on hygienic fish handling techniques.

DEVELOPMENT OF ANTIFUNGAL FINISHES FOR WATER HYACINTH PRODUCTS

This work discusses the research conducted to develop an appropriate agent to enhance the anti-fungal properties of water hyacinth stalks, which are commonly used in handicraft products in Thailand. The objective of the research was to find an agent that would prevent fungal infestations, prolong the shelf life of the products, and ultimately increase the income for the craft makers. The initial experiment involved treating cotton fabrics with three different antifungal solutions: Chitosan, Zinc Pyrithione, and Poly (allylamine hydrochloride). These treated samples were then tested with Aspergillus niger, a common fungal strain, using the standard antifungal test AATCC 30. Among the three finishes, the fabric treated with Poly (allylamine hydrochloride) displayed the highest anti-fungal properties. However, the fabric treated with Zinc Pyrithione effectively inhibited fungal growth but left visible white particles on the fabric. Chitosan, on the other hand, did not significantly inhibit fungal growth. Based on these test results, it was concluded that a solution of Poly (allylamine hydrochloride) can be employed as a finishing agent for water hyacinth to enhance its antifungal properties in water hyacinth-based products. Additionally, it was found that a higher concentration of Poly (allylamine hydrochloride) (100 g/L) is necessary to effectively prevent fungal growth on water hyacinth stalks. By utilizing this research, local Thai communities can enhance the durability and longevity of their water hyacinth handicraft products, reducing the impact of fungal infestations and increasing their income.

Plasmodesmata Function and Callose Deposition in Plant Disease Defense.

Callose, found in the cell walls of higher plants such as β-1,3-glucan with β-1,6 branches, is pivotal for both plant development and responses to biotic and abiotic stressors. Plasmodesmata (PD), membranous channels linking the cytoplasm, plasma membrane, and endoplasmic reticulum of adjacent cells, facilitate molecular transport, crucial for developmental and physiological processes. The regulation of both the structural and transport functions of PD is intricate. The accumulation of callose in the PD neck is particularly significant for the regulation of PD permeability. This callose deposition, occurring at a specific site of pathogenic incursion, decelerates the invasion and proliferation of pathogens by reducing the PD pore size. Scholarly investigations over the past two decades have illuminated pathogen-induced callose deposition and the ensuing PD regulation. This gradual understanding reveals the complex regulatory interactions governing defense-related callose accumulation and protein-mediated PD regulation, underscoring its role in plant defense. This review systematically outlines callose accumulation mechanisms and enzymatic regulation in plant defense and discusses PD's varied participation against viral, fungal, and bacterial infestations. It scrutinizes callose-induced structural changes in PD, highlighting their implications for plant immunity. This review emphasizes dynamic callose calibration in PD constrictions and elucidates the implications and potential challenges of this intricate defense mechanism, integral to the plant's immune system.

Distinguishing between Wheat Grains Infested by Four Fusarium Species by Measuring with a Low-Cost Electronic Nose.

An electronic device based on the detection of volatile substances was developed in response to the need to distinguish between fungal infestations in food and was applied to wheat grains. The most common pathogens belong to the fungi of the genus Fusarium: F. avenaceum, F. langsethiae, F. poae, and F. sporotrichioides. The electronic nose prototype is a low-cost device based on commercially available TGS series sensors from Figaro Corp. Two types of gas sensors that respond to the perturbation are used to collect signals useful for discriminating between the samples under study. First, an electronic nose detects the transient response of the sensors to a change in operating conditions from clean air to the presence of the gas being measured. A simple gas chamber was used to create a sudden change in gas composition near the sensors. An inexpensive pneumatic system consisting of a pump and a carbon filter was used to supply the system with clean air. It was also used to clean the sensors between measurement cycles. The second function of the electronic nose is to detect the response of the sensor to temperature disturbances of the sensor heater in the presence of the gas to be measured. It has been shown that features extracted from the transient response of the sensor to perturbations by modulating the temperature of the sensor heater resulted in better classification performance than when the machine learning model was built from features extracted from the response of the sensor in the gas adsorption phase. By combining features from both phases of the sensor response, a further improvement in classification performance was achieved. The E-nose enabled the differentiation of F. poae from the other fungal species tested with excellent performance. The overall classification rate using the Support Vector Machine model reached 70 per cent between the four fungal categories tested.

Treatment of Bamboo for Sustainable Construction Practise: A Comprehensive Review

Abstract Bamboo is a versatile and sustainable natural resource that has been used for centuries by numerous cultures. Untreated bamboo, on the other hand, has limitations in terms of durability, strength, and decay resistance, which limit its usage in specific conditions. To overcome these restrictions and realise its full potential, researchers have investigated various bamboo treatment methods. This research presents an overview of bamboo treatment methods, effects on their performance, and emphasises possible uses in a variety of construction practises. The study looks into the usage of synthetic resin and synthetic rubber as bamboo protective coatings. These coatings improve durability, water repellence, dimensional stability, mechanical strength, and fungal growth resistance. They are also simple to use and contribute to environmentally friendly practises. To protect bamboo from fungal deterioration and insect infestation, chemical substances such as boron-based additions, zinc chloride, sodium pentachloro-phenate, and copper-chrome-arsenic (CCA) are employed as preservatives. These chemicals increase the longevity of bamboo while also ensuring its structural integrity. The use of epoxy resins to improve the tensile strength of bamboo composites is also being observed. It increases flexural and compressive strength by improving adhesion between bamboo fibres and the matrix. The use of epoxy glue also retains the natural strength and durability of bamboo. Heat treatment of bamboo entails treating it to high temperatures in order to enhance its qualities such as dimensional stability, hardness, and resistance to decay and insect assault. Heat-treated bamboo is used in building, furniture, flooring, and composite materials. Understanding and implementing these treatment procedures can help to encourage the wider use of bamboo as a sustainable and environmentally friendly construction material. The findings of this study have the potential to drive decision-making, encourage innovation, and have a positive impact on the environment, society, and economy. Bamboo may be used as a viable alternative to traditional materials in a variety of sectors by exploiting its unique qualities and improving its durability and strength.

Transcriptional Response of Wolfberry to Infestation with the Endophytic Fusarium nematophilum Strain NQ8GII4.

Fusarium nematophilum NQ8GII4 is an endophytic fungus isolated from the root of healthy wolfberry (Lycium barbarum). Previous studies have reported that NQ8GII4 could dwell in wolfberry roots and enhance the defense responses in wolfberry against root rot, which is caused by F. oxysporum. To further elucidate the molecular mechanism of wolfberry disease resistance induced by NQ8GII4, in the present study, we adopted RNA sequencing analysis to profile the transcriptome of wolfberry response to NQ8GII4 infestation over a time course of 3 and 7 days postinoculation. Gene ontology enrichment analysis revealed that differentially expressed genes (DEGs) were enriched in biological regulation, response to stimulus, signaling, detoxification, immune system process, transporter activity, electron carrier activity, transcription factor activity, nucleic acid binding transcription factor, and antioxidant activity. Through Kyoto Encyclopedia of Genes and Genomes analysis, it was found that many of these DEGs were enriched in pathways related to plant-pathogen interactions, hormone signal transduction, and the phenylpropanoid biosynthesis pathway in wolfberry. This result suggested that innate immunity, phytohormone signaling, and numerous phenylpropanoid compounds comprise a complex defense network in wolfberry. Chloroplast 50S ribosomal proteins were consistently located at the core position of the response in wolfberry following infestation with NQ8GII4 analyzed by the protein-protein interaction network. This study elucidated the molecular mechanism underlying the interaction between NQ8GII4 and wolfberry, clarified the wolfberry immune response network to endophytic fungi infestation, identified candidate resistance genes in wolfberry, and provided a fundamental date for subsequent work.

Monoclonal-Antibody-Based Immunoassays for the Mycotoxins NX-2 and NX-3 in Wheat.

The fungal infestation of crops can cause major economic losses. Toxins produced by the causative fungi (mycotoxins) represent a potential safety hazard to people and livestock consuming them. One such mycotoxin is deoxynivalenol (DON, also known as vomitoxin), a trichothecene associated with Fusarium Head Blight of wheat. DON is commonly found in cereal crops worldwide. A group of trichothecene mycotoxins closely related to DON, the NX toxins, have been reported to occur in the northeastern United States and southern Canada. While many commercial immunoassays are available to detect DON, there are no rapid screening assays for the NX toxins. We describe the development and isolation of three monoclonal antibodies (mAbs) specific towards two NX toxins: NX-2 and NX-3. The mAbs did not recognize DON or several other closely related trichothecenes. One of the mAbs was selected for development of an enzyme-linked immunosorbent assay (ELISA) for NX-2 and NX-3 in wheat. The dynamic ranges for the assay were 7.7 to 127 μg/kg for NX-2 and 59 μg/kg to 1540 μg/kg for NX-3 in wheat. Recoveries from spiked wheat averaged 84.4% for NX-2 and 99.3% for NX-3, with RSDs of 10.4% and 11.3%, respectively (n = 24). The results suggest that this assay can be used to screen for NX toxins in wheat at levels relevant to human food and animal feed safety.

Chitosan nanoemulsion incorporated with Carum carvi essential oil as ecofriendly alternative for mitigation of aflatoxin B1 contamination in stored herbal raw materials

The present investigation entails the first report on entrapment of Carum carvi essential oil (CCEO) into chitosan polymer matrix for protection of stored herbal raw materials against fungal inhabitation and aflatoxin B1 (AFB1) production. Physico-chemical characterization of nanoencapsulated CCEO was performed through Fourier transform infrared spectroscopy, dynamic light scattering, X-ray diffractometry, and scanning electron microscopy. The nanoencapsulated CCEO displayed improved antifungal and AFB1 suppressing potentiality along with controlled delivery over unencapsulated CCEO. The encapsulated CCEO nanoemulsion obstructed the ergosterol production and escalated the efflux of cellular ions, thereby suggesting plasma membrane as prime target of antifungal action in Aspergillus flavus cells. The impairment in methyglyoxal production and modeling based carvone interaction with Afl-R protein validated the antiaflatoxigenic mechanism of action. In addition, CCEO displayed augmentation in antioxidant potentiality after encapsulation into chitosan nanomatrix. Moreover, the in-situ study demonstrated the effective protection of Withania somnifera root samples (model herbal raw material) against fungal infestation and AFB1 contamination along with prevention of lipid peroxidation. The acceptable organoleptic qualities of W. somnifera root samples and favorable safety profile in mice (animal model) strengthen the application of nanoencapsulated CCEO emulsion as nano-fungitoxicant for preservation of herbal raw materials against fungi and AFB1 mediated biodeterioration.

Characterization of Culturable Mycobiome of Newly Excavated Ancient Wooden Vessels from the Archeological Site of Viminacium, Serbia.

Two ancient wooden vessels, specifically a monoxyle (1st century BCE to 1st century CE) and shipwreck (15th to 17th century CE), were excavated in a well-preserved state east of the confluence of the old Mlava and the Danube rivers (Serbia). The vessels were found in the ground that used to be river sediment and were temporarily stored within the semi-underground exhibition space of Mammoth Park. As part of the pre-conservation investigations, the primary aim of the research presented was to characterize the culturable mycobiomes of two excavated wooden artifacts so that appropriate conservation procedures for alleviating post-excavation fungal infestation could be formulated. Utilizing culture-based methods, a total of 32 fungi from 15 genera were identified, mainly Ascomycota and to a lesser extent Mucoromycota sensu stricto. Soft-rot Ascomycota of genus Penicillium, followed by Aspergillus and Cephalotrichum species, were the most diverse of the isolated fungi. Out of a total of 38 isolates, screened on 7 biodegradation plate assays, 32 (84.21%) demonstrated at least one degradative property. Penicillium solitum had the highest deterioration potential, with a positive reaction in 5 separate plate assays. The obtained results further broaden the limited knowledge on the peculiarities of post-excavation soft-rot decay of archaeological wood and indicate the biochemical mechanisms at the root of post-excavation fungal deterioration.

Detection and quantification of aflatoxins in farmers’ stored rice seeds in some selected areas of Bangladesh

Detection and quantification of total aflatoxins in farmers’ stored rice seeds at different storage intervals in two cropping seasons (Boro 2017–2018: cv. BRRI Dhan28 and cv. BRRI Dhan29 and Aman 2017: cv. BR 11 and cv. BRRI dhan49) was focused in this study. Aflatoxin was quantified in two cropping seasons (Boro and Aman). Blotter incubation test was conducted for fungal prevalence assessment and a one-step lateral flow immune-chromatographic assay was used to quantify the aflatoxins. Seed moisture content ranged from 11.59 to 13.32% and aflatoxin concentrations ranged from 2.41 to 11.12 ppb. Variation in fungal contamination in stored seeds was correlated with seed moisture content. The moisture content in stored rice seeds increased with storage time and was positively correlated with fungal infestation and toxin production. The findings of this study indicate that moisture content of stored rice seeds and storage duration are determining factors for aflatoxin contamination.

Root rot induces a core assemblage of bacterial microbiome to prevent disease infection in Sanqi ginseng

Plants rely on rhizosphere microbes as the first line of defense against pathogen invasion and for maintaining the health of itself. Increasing evidence suggests that plants recruit beneficial microbes to the roots, strengthening their resistance to pathogens. However, the response of the rhizosphere core bacterial microbiome to root rot infection remains largely unclear. In this study, we investigated the rhizosphere and bulk soil core bacterial microbiome of healthy and root rot-diseased Sanqi ginseng in genuine production areas in China. We utilized 16S amplicon sequencing, co-occurrence network analysis, and strain culture approaches to explore whether root rot-induced plant rhizosphere alterations in the bacterial core microbiome could improve disease suppression. Root rot infection had a significant impact on the rhizosphere core bacterial microbiome of Sanqi ginseng. Root rot led to a reduction in the diversity and evenness of the core bacterial microbiome in the rhizosphere, while the variability of the core bacterial community in the rhizosphere increased. In response to fungal root rot pathogen infestation, Sanqi ginseng recruited potentially beneficial bacteria with disease-suppressive functions to the rhizosphere, such as Sphingobium, Pseudoxanthomonas, Pseudomonas, Stenotrophomonas, and Flavobacterium. Function prediction analysis demonstrated a remarkable enrichment of several functional genes involved in antibiotic biosynthesis in the rhizosphere that was infected with root rot. Strain isolation and pot addition experiments further confirmed the effectiveness of root rot rhizosphere-specific enrichment of Operational Taxonomic Units (OTUs) for controlling root rot. Furthermore, co-occurrence network analysis indicated that root rot activated the disease-suppressive functions of the rhizosphere core bacterial microbiome by enhancing complexity and connectivity at the expense of network stability. These findings expand our knowledge of plant-microbe interactions and provides new evidence supporting the “cry for help” strategy for rhizosphere responses to root rot.

Bacillus subtilis Edible Films for Strawberry Preservation: Antifungal Efficacy and Quality at Varied Temperatures.

Fungal infestations, particularly from Rhizopus stolonifer, pose significant post-harvest challenges for strawberries, compromising their shelf life and quality. Traditional preservation methods, including refrigeration, offer limited protection against such pathogens. This study introduces an innovative approach, utilizing edible films infused with Bacillus subtilis strains GOS 01 B-67748 and HFC 103, known for their antifungal properties. We demonstrate that these bioactive films not only inhibit fungal growth effectively but also enhance the preservation of strawberries at varying temperatures. The inclusion of Bacillus subtilis in edible films represents a significant advancement in extending the viability of strawberries, surpassing the efficacy of conventional methods. Our findings suggest a promising avenue for natural, safe food preservation techniques, aligning with current consumer preferences for additive-free products. This research contributes to the broader understanding of microbial-based food preservation strategies, offering potential applications across a range of perishable commodities.

Investigation of two-pore K+ (TPK) channels in Triticum aestivum L. suggests their role in stress response

Two-pore K+ (TPK) channels are voltage-independent and involved in stress response in plants. Herein, we identified 12 TaTPK genes located on nine chromosomes in the Triticum aestivum genome. The majority of TaTPK genes comprised two exons. Each TaTPK channel comprised four transmembrane (TM) helices, N- and C-terminal ion-channel domains, two EF-hand domains and one 14-3-3 binding site. Additionally, highly conserved ‘GYGD’ motif responsible for K+ ion specificity, was found in between the TMs in both the ion-channel domains. Nine TaTPK channels were predicted to be localised at the plasma membrane, while three were vacuolar. The protein-protein and protein-chemical interactions indicated the coordinated functioning of the TaTPK channels with the other K+ transporters and their possible interaction with the Ca2+-signaling pathway. Expression studies suggested their importance in both vegetative and reproductive tissues development. Significantly modulated expression of various TaTPK genes during heat, drought, combined heat and drought and salt stresses, and after fungal infestation, depicted their function in stress responses. The miRNAs and transcription factors interaction analyses suggested their role in the hormone, light, growth and development-related, and stress-responsive signaling cascades. The current study suggested vital functions of various TaTPK genes, especially in stress response, and would provide an opportunity for their detailed characterization in future studies.

Examination and analysis of a stored stucco window in the conservation lab of Bab Al-azab area, citadel of Salah Al-din Al-Ayyubi, Cairo Egypt

Historic areas are at the forefront of global attention because of their historical and social traits that reflect human civilization, giving them an economic weight that helps preserve the city's historical identity. For that, the aim of this paper is based on examining and analyzing the components of a deteriorated stucco window kept in the Restoration Lab of Bab Al-azab Area of the Citadel of Salah al-din Al-ayyubi, which was carried out via different techniques. The stucco window used in this study was inspected using a digital microscope and scanning electron microscope to determine the degradation of the stucco and wooden frame's outside surface. Besides, the polarized microscope involves studying minerals by studying the optical properties of stucco. Also, the light microscope was used to identify the wood. Besides, energy dispersive X-ray (EDX) showed the presence of constituent elements for both the stucco and glass. In addition, X-ray diffraction estimated cellulose crystallinity to decrease. A technique called Fourier transform infrared (FTIR) was also used to find changes in lignin, gypsum, anhydrite, and calcite, as well as cellulose and hemicellulose. A microbiological investigation indicated the presence of a fungal infestation on a wooden frame. This study showed that Salah El-Din Castle's semi-separate historical areas can be considered one of its architectural, planning, and historical models, which have their fabric and characteristics.

Bioinspired Living Coating System for Regenerative and Circular Architecture

Surfaces of exposed materials are affected by biotic and abiotic degradation processes. They often are protected by architectural coatings that not only provide a decorative layer but also enhance integrity of the material structure. Common surface treatments often include mineral oil binders and other ingredients that are known to have a negative impact on the environment. To address these issues, an alternative bioinspired concept for materials protection based on engineered fungal biofilm is under development. This paper presents the first results related to the bioreceptivity of building materials and the initial steps of natural biofilm formation. This research concluded that fungal colonisation and the variability of microorganisms is influenced by the type of material and climate condition at the exposure site. Fungal infestation was lower on protected materials (e.g., with commercial coatings). Samples from the eastern and western exposure exhibited the highest fungal colonisation, whereas samples from the northern and southern exposure exhibited the least growth. Furthermore, the samples in close spatial proximity were colonized by different fungal microbiota. It was determined that Aureobasidium sp. is the dominant species in the early phase of colonisation. In the following steps, a bioactive protective coating system that works in synergy with nature will be developed. Based on the initial results Aureobasidium appears to be a viable candidate as an active, living component of a new nature-inspired coating system. The novel protection concept is based on three interrelated components – bioinspiration as a driving force for materials design, bio-based ingredients, and living fungal cells that will provide self-healing and bioremediation capacity. The living coating will be designed to protect various architectonic materials, including porous materials such as biomaterials, concrete, stone, and non-porous, as well as plastics, and metals. The ultimate goal is to advance the development of engineered living materials that interact, adapt, and respond to environmental changes.

The Combined Effect of Lemon Peel Extract and Calcium Chloride on the Physical and Biochemical Quality Parameters of the Dessert Banana (Musa acuminata var. Dwarf Cavendish) Fruit

The dessert banana is a popular fruit worldwide, but its ripening process is greatly accelerated by high temperatures, which eventually leads to an unpleasant taste and the appearance of spots on the skin of the fruits. To slow down the ripening of bananas, expensive strategies are used, which are usually not practical for conventional farmers in less developed countries. In this study, we try to find a less costly alternative. Therefore, the effects of coatings of lemon peel extract (2.5%, 5%, and 10%), calcium chloride (4%), and glycerol (2%) on the shelf life and postharvest quality of the banana fruit (Cavendish) stored at 19–22 °C and 40–60% relative humidity were investigated. Treatment with a mixture of 2.5% lemon peel extract and 2% glycerol resulted in an extension of the shelf life of the dessert banana by up to 6 days and no detectable fungal infestation. The coating solution is an effective alternative to extend the shelf life and reduce quality losses in bananas.

Seed Dormancy Breaking and Germination Rate Improvement in Mucuna (Mucuna bracteata) Seeds using Mechanical and Fungicide Treatments

Mucuna (Mucuna bracteata) is a cover crop for young plants in oil palm plantations. However, it has a very low germination rate due to its hard outer shell and fungi infestation after germination. Thus, this study was conducted to determine the effectivity of mechanical treatment combined with 15-min of Dithane M-45 treatment to improve the germination rate of Mucuna’s seed and its seedling growth. The experiment was performed with the combination of two factors: mechanical treatment and Dithane M-45 (0.00 g/L, 0.05 g/Lg, 0.10 g/L and 0.15 g/L) in pentaplicate for each group. The seeds were sowed on wet cotton, and the data was analyzed using ANOVA (α = 0.05) followed by DMRT (α = 0.05). The shell nicking seed followed by a 0.10 g/L of Dithane M-45 treatment resulted in the best germination rate (88 ± 9.1%), the fastest germination speed (6.29 ± 0.65 %), the shortest mean germination time (4.25 ± 0.87 days), the longest shoot, and the highest of fresh and dry biomass for both shoot and root of the seedlings. Therefore, the shell nicking and fungicide immersion before sowing the seeds could improve Mucuna's germination and seedling growth.

Dissolution kinetics of copper oxide nanoparticles in presence of glyphosate

Recently CuO nanoparticles (n-CuO) have been proposed as an alternative method to deliver a Cu-based pesticide for controlling fungal infestations. With the concomitant use of glyphosate as an herbicide, the interactions between n-CuO and this strong ligand need to be assessed. We investigated the dissolution kinetics of n-CuO and bulk-CuO (b-CuO) particles in the presence of a commercial glyphosate product and compared it to oxalate, a natural ligand present in soil water. We performed experiments at concentration levels representative of the conditions under which n-CuO and glyphosate would be used (∼0.9 mg/L n-CuO and 50 μM of glyphosate). As tenorite (CuO) dissolution kinetics are known to be surface controlled, we determined that at pH 6.5, T ∼ 20 °C, using KNO3 as background electrolyte, the presence of glyphosate leads to a dissolution rate of 9.3 ± 0.7 ×10−3 h−1. In contrast, in absence of glyphosate, and under the same conditions, it is 2 orders of magnitude less: 8.9 ± 3.6 ×10−5 h−1. In a more complex multi-electrolyte aqueous solution the same effect is observed; glyphosate promotes the dissolution rates of n-CuO and b-CuO within the first 10 h of reaction by a factor of ∼2 to ∼15. In the simple KNO3 electrolyte, oxalate leads to dissolution rates of CuO about two times faster than glyphosate. However, the kinetic rates within the first 10 h of reaction are about the same for the two ligands when the reaction takes place in the multi-electrolyte solution as oxalate is mostly bound to Ca2+ and Mg2+.

Effect of Indigenous Beauveria bassiana on the Control of Allocaridala maleyensis (Crawford) in durian plantation areas in eastern region

The spread of Allocaridala maleyensis (Crawford) in durian fields has a great economic impact on durian farmers. Allocaridala maleyensis can invade durian at every stage from the beginning of young leaves until harvesting. Thus, it is necessary to select indigenous entomopathogenic fungi that have the potential to control A. maleyensis in durian fields. The objective of this research was to select indigenous Beauveria bassiana with the ability to control A. maleyensis in durian plantation areas in the eastern region. The insect pest samples were collected from durian orchards in 3 provinces: Chanthaburi, Trat, and Rayong provinces. Fungi isolated from the collected insect pests were then identified and classified by fungi morphology. The isolated fungi were classified as Beauveria bassiana and used as tested fungi to control A. maleyensis. The results showed that B. bassiana at 104 , 106, and 108 spore/ml were able to inhibit the growth of A. maleyensis. Beauveria bassiana at 108 spore/ml completely inhibit mortality nymph (100%) and inhibited adult A. maleyensis (88%). It can be concluded that indigenous B. bassiana should be sprayed on rooster aphids at the nymph stage rather than at the adult stage because the nymph is susceptible to the infestation of entomopathogenic fungi.