Conventional Pesticides Research Articles

Knockdown of double-stranded RNases (dsRNases) enhances oral RNA interference (RNAi) in the corn leafhopper, Dalbulus maidis

The leafhopper Dalbulus maidis is a harmful pest that causes severe damage to corn crops. Conventional chemical pesticides have negative environmental impacts, emphasizing the need for alternative solutions. RNA interference (RNAi) is a more specific and environmentally friendly method for controlling pests and reducing the negative impacts of current pest management practices. Previous studies have shown that orally administered double-stranded RNA (dsRNA) is less effective than injection protocols in silencing genes. This study focuses on identifying and understanding the role of double-stranded ribonucleases (dsRNases) in limiting the efficiency of oral RNAi in D. maidis. Three dsRNases were identified and characterized, with Dmai-dsRNase-2 being highly expressed in the midgut and salivary glands. An ex vivo degradation assay revealed significant nuclease activity, resulting in high instability of dsRNA when exposed to tissue homogenates. Silencing Dmai-dsRNase-2 improved the insects' response to the dsRNA targeting the gene of interest, providing evidence of dsRNases involvement in oral RNAi efficiency. Therefore, administering both dsRNase-specific and target gene-specific-dsRNAs simultaneously is a promising approach to increase the efficiency of oral RNAi and should be considered in future control strategies.

Efficacy of drip irrigation with thiamethoxam on control of Monolepta hieroglyphica and uptake, translocation, and dietary risk of thiamethoxam in maize.

Monolepta hieroglyphica (Motschulsky) is an important agricultural pest that causes significant economic losses in terms of crop production. Conventional pesticide spraying treatments can result in pesticide drift, endanger nontarget organisms, and cause pests to fly away, resulting in unsatisfactory prevention and control effects. To study the effect of thiamethoxam on the control of maize M. hieroglyphica, a field experiment was conducted to determine the optimal thiamethoxam application dose, its spatial and temporal distribution dynamics and its dietary risk based on its control effect when applied by spray and drip irrigation. The results of the field trials showed that compared with spray irrigation, drip irrigation resulted in greater control starting from the 5th day. This result was due to the hysteresis effect of thiamethoxam being first absorbed by the roots and then continuously transferred upward, where it accumulates. After 30 days of drip irrigation with 75 and 150 g a.i. ha-1 thiamethoxam, the control effect on M. hieroglyphica was 32.41-49.44% and 69.77-80.57%, respectively. The results of the dietary risk assessment showed that the risk of thiamethoxam ingestion through maize kernels was acceptable regarding its effect on human health. Drip irrigation with thiamethoxam can improve the effective utilization rate of pesticides, achieve precise control of maize M. hieroglyphica, and provide a new method for sustainable agricultural production. This article is protected by copyright. All rights reserved.

Degradable PDA@PNIPAM-TA Nanocomposites for Temperature- and NIR light-Controlled Pesticide Release.

Controlled pesticide delivery systems offer many distinctive advantages over conventional pesticide formulations. In this work, degradable poly(N-isopropylacrylamide) (PNIPAM)-tannic acid (TA) microgels and multifunctional PDA@PNIPAM-TA nanocomposites were prepared in a high-gravity rotating packed bed reactor (RPB) for smart pesticide delivery and release. The as-prepared microgels and nanocomposites showed reversible temperature-dependent swelling/deswelling behavior and irreversible pH-induced degradation. A dynamic contact angle test suggested that the introduction of TA and PDA into the PNIPAM matrix could enhance foliar adhesion and deposition efficiency. The nanocomposites were further used for the encapsulation and delivery of imidacloprid (IMI) to protect it from rapid photolysis and improve its pest-control efficiency. Their thermoresponsive behavior as well as pesticide loading capacity could be tuned by tailoring the PNIPAM-TA shell thickness, which could be varied by the NIPAM amount. The release rate of IMI from the core/shell nanocomposites was positively correlated with environmental temperature and near-infrared (NIR) light, which was adaptive to the positive temperature-dependent toxicity correlation of IMI and the increasing trend of pests under high temperature. The cumulative release of IMI was 23.5% at 25 °C, while it was 81.2% at 40 °C after 24 h of incubation, and the release rate was greatly enhanced under NIR irradiation. The results indicated that the facile control of pesticide release could be realized by regulating environmental conditions. This work also provides an idea for using high-gravity technology to conveniently construct a smart, effective, and environmentally friendly pesticide delivery system for sustainable crop protection.

RNAi-chitosan biopesticides for managing forest insect pests: an outlook

The expanding world population demands superior forest protection to fulfil feasible environmental certainty. The persistent pest infestations negatively influence forest health and cause substantial economic losses. In contrast, the traditional use of conventional pesticides results in a loss of soil microbial biodiversity, a drop in the population of pollinators, and adverse effects on other non-target organisms, including humans. Global forestry is looking for solutions to reduce the adverse environmental effects of current chemical pesticides. RNAi-nanotechnology has recently drawn much attention for its use in pest management. The advantages of engineered RNAi-chitosan nano-formulations in terms of simple digestion and dissolution, non-toxicity, high adsorption power, potential biodegradation in nature, and widespread availability and cost-effectiveness, have been well documented for pest management in agroecosystems. However, deploying such control strategies in forest ecosystems is still pending and demands further research. Hence, we highlight the putative uses of RNAi-chitosan biopesticides and their preparation, characterization, and putative application methods for forest pest management. We also discussed potential environmental risks and plausible mitigation strategies.

Effects of novel and commercial phytochemicals on beneficial arthropods

Pesticides have been proven to be noxious to non-target organisms, including beneficial arthropods. Moreover, pesticide applications, kill a broad range of natural enemies and pollinators, resulting in pest outbreaks of pesticide resistant phytophagous species and a worldwide shrinking of the pollinators’ populations. Natural pesticides called phytochemicals, are considered environmentally friendly alternatives to conventional pesticides, presenting lower risk to animals and humans. To minimize the environmental impact and the disruption of the species interactions, the potential lethal and sublethal effects of phytochemicals on beneficial arthropods must be evaluated.The aim of this study was to evaluate the toxicity of five phytochemical pesticides (Requiem®, Eradicoat®, Prev-Am®, FLiPPER®, BPA044I), on two predatory mites, two predatory insects and one pollinator, which are all important components of current integrated pest management (IPM) programs. The lethal and sublethal effects of the phytochemicals were evaluated on the phytoseiid mites (Acari, Phytoseiidae), Phytoseiulus persimilis (Evans), and Amblyseius swirskii (Athias-Henriot), as well as the predatory insects Nesidiocoris tenuis (Reuter) (Heteroptera: Miridae) and Orius laevigatus (Fieber) (Heteroptera: Anthocoridae). Also, the lethal effects were evaluated on the pollinator Bombus terrestris L. (Hymenoptera: Apidae) which is used in greenhouse pollination. We evaluated the acute toxicity of the phytochemicals on adult arthropods and the effects on the predator fecundity, when exposed directly and indirectly through residues.Requiem® and BPA044I were harmless or slightly harmful to the mite and insect predators (toxicity <49%), nor did they affect their fertility, according to the IOBC classification. Eradicoat® was harmless to N. tenuis, but it had moderate toxicity to mites and O. laevigatus (<50%). Prev-Am® had high toxicity (>50%) on mites and low on insects, while FLiPPER® was moderately to highly toxic to all predators. The tested phytochemical products exhibited very low toxicity on the pollinator B. terrestris, with either oral or topical exposure and very high repellency. Overall, the evaluation of natural pesticide effects on biocontrol agents and pollinators is crucial for implementing successful IPM strategies.

Enhanced control efficacy of spinosad on corn borer using polylactic acid encapsulated mesoporous silica nanoparticles as a smart delivery system

Asion corn borer (Ostrinia furnacalis (Guenee)) is one of the most important factors affecting the normal growth and yield of corn. However, chemical control methods currently in use cause severe pollution. In the present study, aminated mesoporous silica nanoparticles (MSNs-NH2) and polylactic acid (PLA) were used as the carrier and capping agent respectively to construct an insect gut microenvironment nano-response system that loaded spinosad, a biopesticide used to control O. furnacalis. The resulting spinosad@MSNs-PLA demonstrated high loading capacity (38.6 %) and improved photostability of spinosad. Moreover, this delivery system could intelligently respond to the intestinal microenvironment of the corn borer's gut and achieve the smart release of spinosad. Compared with the conventional pesticide, spinosad@MSNs-PLA exhibited superior efficacy in controlling the O. furnacalis and could uptake and transport in maize plants without adverse effects on their growth. Furthermore, the toxicity of spinosad@MSNs-PLA on zebrafish was reduced by over 50 times. The prepared spinosad@MSNs-PLA has great potential and could be widely applied in agricultural production in the future. This approach could improve the utilization of pesticide and reduce environmental pollution. In addition, MSNs-PLA nano vectors provide new ideas for the control of other borer pests.

Agrohomoeopathy: Bridging Nature and Agriculture for Sustainable Crop Health

Agro-Homeopathy is an emerging field of science that seeks to revolutionize agricultural practices by integrating the principles of homeopathy with sustainable farming methods. This innovative approach aims to promote crop health, enhance productivity, and reduce the reliance on conventional chemical inputs. Drawing inspiration from homeopathy, which focuses on stimulating the self-healing abilities of living organisms, Agro-Homeopathy utilizes potentized remedies to treat and prevent diseases in crops. These remedies are then applied to crops in various forms, such as sprays, soil treatments, or through irrigation systems. By stimulating the plant's natural defense mechanisms and strengthening its vitality, Agro-Homeopathy aims to create an optimal environment for crops to thrive. The potential benefits of Agro-Homeopathy are manifold. Firstly, it offers a sustainable alternative to conventional chemical pesticides and fertilizers, minimizing environmental contamination and reducing the risk of chemical residues in food. Secondly, Agro-Homeopathy has shown promising results in enhancing crop resistance to diseases, pests, and adverse environmental conditions. Additionally, it has the potential to improve nutrient uptake, strengthen plant roots, and promote overall plant vigor. Rigorous scientific studies are needed to evaluate its effectiveness across different crops, regions, and farming systems. In conclusion, Agro-Homeopathy holds great promise as a sustainable and eco-friendly approach to agriculture. By harnessing the power of natural remedies and principles of homeopathy, this field of science offers a holistic and harmonious way of nurturing crops, supporting biodiversity, and safeguarding the environment for future generations. Keywords: Homoeopathy, Agro-Homoeopathy, Biotic and Abiotic stress, Fertilizers, Pesticides, Insecticides.

Antibacterial Efficacy of Green Synthesized Silver Nanoparticles Using Salvia nubicola Extract against Ralstonia solanacearum, the Causal Agent of Vascular Wilt of Tomato.

Ralstonia solanacearum is a phytopathogen causing bacterial wilt diseases of tomato and affecting its productivity, which leads to prominent economic losses annually. As an alternative to conventional pesticides, green synthesized nanoparticles are believed to possess strong antibacterial activities besides being cheap and ecofriendly. Here, we present the synthesis of silver nanoparticles (Sn-AgNPs) from medicinally important aqueous plant extracts of Salvia nubicola. Characterization of biologically synthesized nanoparticles was performed through UV-vis spectrophotometry, Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy (TEM), and thermogravimetric analysis. The antibacterial activity of the biosynthesized silver nanoparticles was tested against the phytopathogen R. solanacearum through in vitro experiments. Preliminary phytochemical analysis of the plant extracts revealed the presence of substantial amounts of flavonoids (57.08 mg GAE/g), phenolics (42.30 mg GAE/g), tannins, and terpenoids. The HPLC phenolic profile indicated the presence of 25 possible bioactive compounds. Results regarding green synthesized silver nanoparticles revealed the conformation of different functional groups through FTIR analysis, which could be responsible for the bioreduction and capping of Ag ions into silver NPs. TEM results revealed the spherical, crystalline shape of nanoparticles with the size in the range of 23-63 nm, which validates SEM results. Different concentrations of Sn-AgNPs (T1 (500 μg/mL) to T7 (78.1 μg/mL)) with a combination of plant extracts (PE-Sn-AgNPs) and plant extracts alone exhibited an efficient inhibition of R. solanacearum. These findings could be used as an effective alternative preparation against the bacterial wilt of tomato.

Ecotoxicity studies of two atrazine nanoformulations: From the evaluation of stability in media to the effects on aquatic organisms

In the field of agriculture, nanopesticides have been developed as an alternative to the conventional pesticides, being more efficient for pest control. However, before their widespread application it is essential to evaluate their safe application and no environmental impacts. In this paper, we evaluated the toxicological effects of two kinds of atrazine nanoformulations (ATZ NPs) in different biological models (Raphidocelis subcapitata, Danio rerio, Lemna minor, Artemia salina, Lactuca sativa and Daphnia magna) and compared the results with nanoparticle stability over time and the presence of natural organic matter (NOM). The systems showed different characteristics for Zein (ATZ NPZ) (184 ± 2 nm with a PDI of 0.28 ± 0.04 and zeta potential of (30.4 ± 0.05 mV) and poly(epsilon-caprolactone (ATZ PCL) (192 ± 3 nm, polydispersity (PDI) of 0.28 ± 0.28 and zeta potential of −18.8 ± 1.2 mV) nanoparticles. The results showed that there is a correlation between nanoparticles stability and the presence of NOM in the medium and Environmental Concentrations (EC) values. The stability loss or an increase in nanoparticle size result in low toxicity for R. subcapitata and L. minor. For D. magna and D. rerio, the presence of NOM in the medium reduces the ecotoxic effects for ATZ NPZ nanoparticles, but not for ATZ NPs, showing that the nanoparticles characteristics and their interaction with NOM can modulate toxic effects. Nanoparticle stability throughout the evaluation must be considered and become an integral part of toxicity protocol guidelines for nanopesticides, to ensure test quality and authentic results regarding nanopesticide effects in target and non-target organisms.

RNA-Based Control of Fungal Pathogens in Plants.

Our duty to conserve global natural ecosystems is increasingly in conflict with our need to feed an expanding population. The use of conventional pesticides not only damages the environment and vulnerable biodiversity but can also still fail to prevent crop losses of 20-40% due to pests and pathogens. There is a growing call for more ecologically sustainable pathogen control measures. RNA-based biopesticides offer an eco-friendly alternative to the use of conventional fungicides for crop protection. The genetic modification (GM) of crops remains controversial in many countries, though expression of transgenes inducing pathogen-specific RNA interference (RNAi) has been proven effective against many agronomically important fungal pathogens. The topical application of pathogen-specific RNAi-inducing sprays is a more responsive, GM-free approach to conventional RNAi transgene-based crop protection. The specific targeting of essential pathogen genes, the development of RNAi-nanoparticle carrier spray formulations, and the possible structural modifications to the RNA molecules themselves are crucial to the success of this novel technology. Here, we outline the current understanding of gene silencing pathways in plants and fungi and summarize the pioneering and recent work exploring RNA-based biopesticides for crop protection against fungal pathogens, with a focus on spray-induced gene silencing (SIGS). Further, we discuss factors that could affect the success of RNA-based control strategies, including RNA uptake, stability, amplification, and movement within and between the plant host and pathogen, as well as the cost and design of RNA pesticides.

Evaluation of the Stability of a 1,8-Cineole Nanoemulsion and Its Fumigant Toxicity Effect against the Pests Tetranychus urticae, Rhopalosiphum maidis and Bemisia tabaci.

Pest control is a main concern in agriculture. Indiscriminate application of synthetic pesticides has caused negative impacts leading to the rapid development of resistance in arthropod pests. Plant secondary metabolites have been proposed as a safer alternative to conventional pesticides. Monoterpenoids have reported bioactivities against important pests; however, due to their high volatility, low water solubility and chemical instability, the application of these compounds has been limited. Nanosystems represent a potential vehicle for the broad application of monoterpenoids. In this study, an 1,8-cineole nanoemulsion was prepared by the low energy method of phase inversion, characterization of droplet size distribution and polydispersity index (PDI) was carried out by dynamic light scattering and stability was evaluated by centrifugation and Turbiscan analysis. Fumigant bioactivity was evaluated against Tetranychus urticae, Rhopalosiphum maidis and Bemisia tabaci. A nanoemulsion with oil:surfactant:water ratio of 0.5:1:8.5 had a droplet size of 14.7 nm and PDI of 0.178. Formulation was stable after centrifugation and the Turbiscan analysis showed no particle migration and a delta backscattering of ±1%. Nanoemulsion exhibited around 50% more bioactivity as a fumigant on arthropods when compared to free monoterpenoid. These results suggest that nanoformulations can provide volatile compounds of protection against volatilization, improving their bioactivity.

From identification to forecasting: the potential of image recognition and artificial intelligence for aphid pest monitoring.

Insect monitoring has gained global public attention in recent years in the context of insect decline and biodiversity loss. Monitoring methods that can collect samples over a long period of time and independently of human influences are of particular importance. While these passive collection methods, e.g. suction traps, provide standardized and comparable data sets, the time required to analyze the large number of samples and trapped specimens is high. Another challenge is the necessary high level of taxonomic expertise required for accurate specimen processing. These factors create a bottleneck in specimen processing. In this context, machine learning, image recognition and artificial intelligence have emerged as promising tools to address the shortcomings of manual identification and quantification in the analysis of such trap catches. Aphids are important agricultural pests that pose a significant risk to several important crops and cause high economic losses through feeding damage and transmission of plant viruses. It has been shown that long-term monitoring of migrating aphids using suction traps can be used to make, adjust and improve predictions of their abundance so that the risk of plant viruses spreading through aphids can be more accurately predicted. With the increasing demand for alternatives to conventional pesticide use in crop protection, the need for predictive models is growing, e.g. as a basis for resistance development and as a measure for resistance management. In this context, advancing climate change has a strong influence on the total abundance of migrating aphids as well as on the peak occurrences of aphids within a year. Using aphids as a model organism, we demonstrate the possibilities of systematic monitoring of insect pests and the potential of future technical developments in the subsequent automated identification of individuals through to the use of case data for intelligent forecasting models. Using aphids as an example, we show the potential for systematic monitoring of insect pests through technical developments in the automated identification of individuals from static images (i.e. advances in image recognition software). We discuss the potential applications with regard to the automatic processing of insect case data and the development of intelligent prediction models.

Effect of nanopesticides (azoxystrobin and bifenthrin) on the phenolic content and metabolic profiles of strawberries (Fragaria × ananassa).

Nanoencapsulation has opened promising fields of innovation for pesticides. Conventional pesticides can cause side effects on plant metabolism. To date, the effect of nanoencapsulated pesticides on plant phenolic contents has not been reported. In this study, a comparative evaluation of the phenolic contents and metabolic profiles of strawberries was performed for plants grown under controlled field conditions and treated with two separate active ingredients, azoxystrobin and bifenthrin, loaded into two different types of nanocarriers (Allosperse® polymeric nanoparticles and SiO2 nanoparticles). There were small but significant decreases of the total phenolic content (9%) and pelargonidin 3-glucoside content (6%) in strawberries treated with the nanopesticides. An increase of 31% to 125% was observed in the levels of gallic acid, quercetin, and kaempferol in the strawberries treated with the nanoencapsulated pesticides compared with the conventional treatments. The effects of the nanocarriers on the metabolite and phenolic profiles was identified by principal component analysis. Overall, even though the effects of nanopesticides on the phenological parameters of strawberry plants were not obvious, there were significant changes to the plants at a molecular level. In particular, nanocarriers had some subtle effects on plant health and fruit quality through variations in total and individual phenolics in the fruits. Further research will be needed to assess the impact of diverse nanopesticides on other groups of plant metabolites. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

A comprehensive study of recent bioremediation approaches and techniques for a green and sustainable environment

AbstractAim and objective of this study focus on the bioremediation approaches and techniques for a clean and sustainable environment. Recently agriculture practices are facing enormous problems because of industry wastages are dumped into lakes and rivers etc. Farmers rely primarily on large‐scale chemical fertilizers to increase yields. To preserve and retain the nutrients in the soil and increase crop production modern bioremediation approaches and techniques may be incorporated. It explains the role of microorganisms and industrial waste treatment technology. The soil microbiome and biopesticides are alternatives to conventional chemical pesticides. The contaminants of industrial wastes and their unpleasant effects are brief. The Recent types of bioremediation methods like microbial, genetically modified microbes, and phytobial technique are analyzed for mitigating the industrial wastages and enhanced bioremediation. Hence, this study elaborates various bioremediation approaches and techniques for a green and sustainable environment.

Rhizosphere bacteria show a stronger response to antibiotic-based biopesticide than to conventional pesticides

The plant microbiota can substantially contribute to various functions related to host health, fitness, and productivity. Therefore, maintaining the integrity of the microbiota is beginning to be seen as a crucial factor in modern agriculture. Here, we evaluated the effects of two chemical pesticides (azoxystrobin and carbendazim) and an antibiotic-based biopesticide (wuyiencin) on the rhizosphere microbiome of tomato plants. It was found that all treatments resulted in changes in the bacterial community structure to varying degrees. The most pronounced changes were observed with the biopesticide, which resulted in an enrichment of Streptomyces in the microbiome. In contrast, the relative abundance of Actinobacteria decreased in samples that were treated with low and high dosages of carbendazim. Clostridia were enriched after the applications of azoxystrobin and wuyiencin. When functioning of the microbiome was assessed, it was shown that genes encoding multidrug efflux pumps and ABC transporters related to nutrient uptake were enriched. This enrichment is likely to overcome potentially negative effects linked to the exposure to the employed substances. The study provides new insights into the potential of different pesticides to modulate native plant microbiomes, and thus highlights the importance to include such evaluations when new active agents are developed.

Comparative Environmental Impact Assessment of Copper-Based Nanopesticides and Conventional Pesticides

Comparative Environmental Impact Assessment of Copper-Based Nanopesticides and Conventional Pesticides

Nanopesticides: A Review on Current Research and Future Perspective

AbstractThe survival of humans depends critically on crop production, making crop protection absolutely essential. Numerous studies have suggested that nanopesticides could soon fully replace conventional pesticides since they are far more effective than those now in use. Due to an increase in their surface‐to‐volume ratio, nanomaterials exhibit different properties from their bulk counterparts. Nanopesticides are pesticides that have been made with these nanoparticles and have a high application efficiency and significantly fewer hazardous environmental impacts than pesticides that have been made chemically. Various formulation strategies, which include the containment of the active substance by the nanoparticles, have previously been established, exhibiting promising effects on the pests. Target specificity, high stability, and controlled active ingredients (AIs) release are a few of the noteworthy qualities these nanopesticides offer. The development of green nanopesticides derived from nature, which have very low ecotoxicities and nanoscale qualities, can also have a significant positive impact on crop output. However, before being mass‐produced and used, the discovery still has to be thoroughly examined to determine its effects on people and the environment due to the lack of conclusive proof demonstrating its toxicity. This paper aims to represent the use of nanopesticides in crop protection and a detailed overview of the various methods for the formulation of nanopesticides. Also, the possible negative impacts on the non‐target species by the application of nanopesticides have been briefly discussed. The need for the development of green nanopesticides to avoid the negative aspects of nanopesticides has also been highlighted.

Exploring the potency of curcumin and phyto-compounds as inhibitors of tomato yellow leaf curl virus-sardinia's DNA-binding domain: A computational approach

BackgroundWith the current rise of Tomato yellow leaf curl virus-Sardinia (TYLCV-Sar), a pathogen causing significant yield losses, conventional pesticides have proven inadequate. This necessitates the exploration of innovative and environmentally benign measures for virus control. An understudied avenue in this context is the utilization of plant specialized metabolites, such as phytoconstituents, which can potentially offer sustainable and effective solutions. AimThis study aimed to identify potent phytoconstituents derived from Curcuma longa that could combat TYLCV-Sar effectively, with a focus on the nucleocapsid, the virus's crucial DNA-binding domain. Another objective was to assess the impact of these phytoconstituents on the plant's resilience to abiotic stress, particularly drought, a factor significantly contributing to crop productivity. ResultsWe carried out virtual screening and accelerated molecular re-docking on Curcuma longa extracts from PubChem database. Our findings revealed that Curcumin emerged as the most potent compound against the nucleocapsid of TYLCV-Sar, demonstrating a promising docking score of −10.59 kcal/mol. Furthermore, we observed that tomato plants treated with Curcumin exhibited enhanced drought resistance, leading to a potential increase in yield. The molecular dynamics simulation results further supported the stability of the Curcumin-nucleocapsid complex, reinforcing its efficacy. ConclusionOur study concludes that Curcumin, a phytocompound derived from Curcuma longa, can act as a potent inhibitor of the active site of the TYLCV-Sar nucleocapsid. This finding represents a potential breakthrough in controlling the spread of the virus and enhancing crop productivity by improving drought resistance. Future directionsOur research highlights the significance of plant metabolites as a novel approach to disease control in crops. This study opens avenues for future research, warranting extensive in vitro and in vivo experimentation to further validate the computational findings. Furthermore, our study underscores the importance of interdisciplinary approaches in developing sustainable agriculture practices, integrating biophysics, biochemistry, and mathematical modeling.

Biopesticides provide inadequate control of three foliar bacterial diseases of tomato transplants

There are three important diseases caused by bacterial pathogens affecting tomato foliage on seedlings in the greenhouse and on mature plants in the field: bacterial canker, bacterial spot, and bacterial speck. Their causal agents are seedborne and the greenhouse environment is conducive for their multiplication and spread; therefore, control measures should be targeted to transplant production to reduce the risk of epidemics in the field. A tank-mix of copper and mancozeb or streptomycin are standard treatments to prevent or manage these diseases in the greenhouse, but the presence of copper and/or streptomycin resistant strains makes it difficult to achieve consistent control. Increasing demand for biopesticides to avoid control failure due to pesticide resistance and reduce the use of conventional pesticides has led to many products being developed. We evaluated three registered biopesticides (Regalia, Stargus, and TerraGrow) and five products in development: three botanicals (AOMMA-Agro, CranShield Plus, and CranProtect), a biological bacterial biofilm inhibitor (SP8010), and Zinkicide. Products were applied singly or in combination to assess their efficacy against three bacterial diseases of tomato seedlings caused by four pathogens, compared to a tank mixture of copper plus mancozeb alternated with streptomycin (grower standard) and a non-treated control. The grower standard provided the best control in three of the four experiments, while the biopesticides were inconsistent or ineffective in controlling each of the four pathogens in this study.

Laboratory evaluation of insect growth regulators against the spotted wing drosophila, Drosophila suzukii

Drosophila suzukii (Diptera: Drosophilidae) is an invasive species that causes great damages to many stone and small fruits, resulting in reduced fruit production and high economic losses. The concern about this pest has led to the research of a wide range of possible control methods. However, the main control strategies are still based in insecticide applications. The efficacy of different insect growth regulators (IGRs), which have better ecotoxicological profile than conventional pesticides, was evaluated to test their feasibility for the control of this pest. When adult flies fed for three days on artificial diet surface-treated with lufenuron, cyromazine or pyriproxyfen, no adult offspring developed. However, adult offspring production progressively recovered when flies were transferred to non-treated diet. When adult flies fed continuously for 19 days on surface-treated artificial diet, lufenuron, cyromazine and pyriproxyfen completely suppressed the production of viable offspring while azadirachtin and tebufenozide reduced offspring production by more than a half compared to the untreated control. Nevertheless, these were transient non-permanent effects since viable offspring was produced shortly after females fed on treated diet were transferred to non-treated diet. The results observed in additional choice and egg-transfer assays indicate a vertical transmission of lufenuron and cyromazine from treated females to their offspring whereas the effect of pyriproxyfen seems to be related to the feeding of larvae on treated diet, although effects on reproductive processes cannot be discarded. In addition, choice assays showed no repellent effect on oviposition by lufenuron, cyromazine and pyriproxyfen.