Advances in research and utilization of botanical pesticides for agricultural pest management in Inner Mongolia, China.

Traditional Chinese herbal medicines not only cure human diseases, but also play an important role as insecticides. Compared with conventional chemical agents, traditional Chinese herbal medicines are characterized by low toxicity, low residues, and being eco-friendly, and they have become a research hotspot. Traditional Chinese herbal medicines have tremendous flexibility and indefinite potential. Therefore, this paper reviewed the types of insecticides belonging to traditional Chinese herbal medicines in Inner Mongolia, China, including their traditional uses, secondary metabolites, biological activities, action mechanisms, application methods, and development status. In addition, the most relevant issues involved in the development of traditional Chinese herbal medicines was discussed. We believe that traditional Chinese herbal medicines can be better implemented and developed; such that its other advantages, such as an insect repellent, can be promoted. Moreover, this study lays a solid foundation for further research on traditional Chinese herbal medicines in Inner Mongolia, China.

Demonstration of the synergistic effect of biochar and Trichoderma harzianum on the development of Ralstonia solanacearum in eggplant.

Soil degradation has been accelerated by the use of chemical pesticides and poor agricultural practices, which has had an impact on crop productivity. Recently, there has been a lot of interest in the use of eco-friendly biochar applications to enhance soil quality and sequester carbon in sustainable agriculture. This study aimed to determine the individual and combined effects of Leaf Waste Biochar (LWB) and the bio-control agent Trichoderma harzianum (BCA) on the development of bacterial wilt in eggplants (Solanum melongena) caused by Ralstonia solanacearum (RS). The effects of LWB and BCA on eggplant physiology and defense-related biochemistry were comprehensively examined. Inoculated (+RS) and un-inoculated (-RS) eggplants were grown in potting mixtures containing 3% and 6% (v/v) LWB, both with and without BCA. The percentage disease index was considerably reduced (90%) in plants grown in the 6% LWB+ BCA amended treatments. Moreover, the plants grown in LWB and inoculated with BCA had higher phenolics, flavonoids and peroxidase contents compared to the non-amended control. The level of NPK was significantly increased (92.74% N, 76.47% P, 53.73% K) in the eggplants cultivated in the 6% LWB + BCA composition. This study has shown that the association of T. harzianum with biochar improved plant growth and reduced R. solanacearum induced wilt. Furthermore, the combined impact of biochar and T. harzianum was greater in terms of wilt suppression and increase in plant physiological measurements when the biochar concentration was 6%. Biochar and bio-control agents triggered biochemical alterations, thus enhancing the management of disease-infested soils.

Response of Pasture Grasses to Organic Fertilizer Produced from Black Soldier Fly Frass.

Livestock and dairy farmers are increasingly required to maintain productivity and profitability while mitigating the environmental harm associated with high-input agriculture. Accordingly, to reduce reliance on synthetic fertilizers, a wide range of organically derived products are being evaluated for their effects on sward growth and forage quality. This study used glasshouse experiments to investigate the responses of four grass species to a novel organic fertilizer derived from the mass production of black soldier fly larvae [Hermetia illucens, HexaFrass™, Meath, Ireland]. Although there was some variability among trials, overall our results indicate that application of HexaFrass produced increased shoot growth of Perennial Ryegrass (PRG; Lolium perenne L.), Timothy (Phleum pratense L.), and Cocksfoot (Dactylis glomerata L.) compared with growth achieved in no-fertilizer control plants. In addition to increases in shoot fresh and dry weight, shoot chlorophyll content was also positively related to the HexaFrass application rate. At nitrogen-equivalent application rates, HexaFrass resulted in lower shoot growth compared with the application of urea, suggesting that the nitrogen contained in HexaFrass may not be immediately plant-available. Of relevance to grazing or silage systems, the addition of HexaFrass resulted in increased shoot regrowth of PRG and Timothy after shoots had been cut. Based on our results, insect-frass-based fertilizers may have a role in low input, organic, and/or regenerative pasture-based livestock systems, although issues may occur due to the relatively high costs and low availability compared with other organic soil amendments such as farmyard manure and slurry.

Agrochemical-free genetically modified and genome-edited crops: Towards achieving the United Nations sustainable development goals and a 'greener' green revolution.

Sustainable farming on ever-shrinking agricultural land and declining water resources for the growing human population is one of the greatest environmental and food security challenges of the 21st century. Conventional, age-old organic farming practices alone, and foods based on costly cellular agriculture, do not have the potential to be upscaled to meet the food supply challenges for feeding large populations. Additionally, agricultural practices relying on chemical inputs have a well-documented detrimental impact on human health and the environment. As the available farming methods have reached their productivity limits, new approaches to agriculture, combining friendly, age-old farming practices with modern technologies that exclude chemical interventions, are necessary to address the food production challenges. Growing genetically modified (GM) crops without chemical inputs can allow agricultural intensification with reduced adverse health and environmental impacts. Additionally, integrating high-value pleiotropic genes in their genetic improvement coupled with the use of modern agricultural technologies, like robotics and artificial intelligence (AI), will further improve productivity. Such 'organic-GM' crops will offer consumers healthy, agrochemical-free GM produce. We believe these agricultural practices will lead to the beginning of a potentially new chemical-free GM agricultural revolution in the era of Agriculture 4.0 and help meet the targets of the United Nations Sustainable Development Goals (SDGs). Furthermore, given the advancement in the genome editing (GE) toolbox, we ought to develop a new category of 'trait-reversible GM crops' to avert the fears of those who believe in ecological damage by GM crops. Thus, in this article, we advocate farming with no or minimal chemical use by combining chemical-free organic farming with the existing biofortified and multiple stress tolerant GM crops, while focusing on the development of novel 'biofertilizer-responsive GE crops' and 'trait-reversible GE crops' for the future.

Seedcorn maggot response to planting date, cover crops, and tillage in organic cropping systems.

Seedcorn maggot, Delia platura (Meigen) (Diptera: Anthomyiidae), is an economically important early-season pest of corn and soybean in the United States. Adult seedcorn maggot is attracted to decomposing plant residues for oviposition, creating potential management issues where growers typically use tillage to incorporate fertility amendments and to create a seedbed. The use of growing degree-day models to time planting dates is an important tool for effectively managing this pest, but their use has not been examined in organic crop production. Here, we report the results of experiments to determine the effects of cover crops, tillage, and relative planting date on seedcorn maggot in corn and soybean in 2 experiments: The first during the transition to organic from conventional management and the second during the 3 yr following organic certification in central Pennsylvania, United States. Overall, delaying the planting date by 1-2 wk reduced fly emergence in corn, but not in soybean in both experiments. Seedcorn maggot emergence was also consistently greater in corn than in soybean, with 6 times more flies in corn than in soy. About 15 times more seedcorn maggot flies emerged from corn in treatments in which cover crops were managed with tillage compared to treatments in which cover crops were terminated with a roller-crimper followed by no-till planting of corn. Fly emergence was negatively related to the proportion of legumes in the cover crop mixture preceding corn. These results can help inform soil, cover crop, and crop decisions for organic growers in the Mid-Atlantic United States.

Anaerobic Soil Disinfestation and Vermicompost to Manage Bottom Rot in Organic Lettuce.

Rhizoctonia solani Kühn (teleomorph: Thanatephorus cucumeris [Frank] Donk) is an aggressive soilborne pathogen with a wide host range that survives saprophytically between crops, presenting a challenge for organic vegetable farmers who lack effective management tools. A 2-year field experiment was conducted at two organic farms to compare anaerobic soil disinfestation (ASD) and worm-cured compost (vermicompost) to manage bottom rot caused by R. solani subspecies AG1-IB in field-grown organic lettuce (Lactuca sativa). At each farm, four replicate plots of seven treatments were arranged in a randomized complete block design. Randomization was restricted by grouping treatments to evaluate ASD, and treatments to evaluate vermicompost in starter plugs. ASD experiment treatments were three different ASD carbon sources that are commonly used and widely available to local farmers in Vermont: compost, cover crop residues, and poultry manure fertilizer, as well as a tarped control. Vermicompost experimental treatments were vermicompost compared with two types of controls: a commercial biocontrol product (RootShield PLUS + G), and unamended (untarped control). This study demonstrated that the ASD method is achievable in a field setting on Vermont farms. However, neither ASD nor vermicompost produced significant disease suppression or resulted in higher marketable yields than standard growing practices. Given the laborious nature of ASD, it is likely more appropriate in a greenhouse setting with high-value crops that could especially benefit from being grown in plastic tarped beds (e.g., tomatoes and strawberries). This study is the first known attempt of field-implemented ASD for soil pathogen control in the northeastern United States.

Different microbial communities in paddy soils under organic and nonorganic farming.

Organic agriculture is a farming method that provides healthy food and is friendly to the environment, and it is developing rapidly worldwide. This study compared microbial communities in organic farming (Or) paddy fields to those in nonorganic farming (Nr) paddy fields based on 16S rDNA sequencing and analysis. The predominant microorganisms in both soils were Proteobacteria, Chloroflexi, Acidobacteria, Actinobacteria, and Nitrospirota. The alpha diversity of the paddy soil microbial communities was not different between the nonorganic and organic farming systems. The beta diversity of nonmetric multidimensional scaling (NMDS) revealed that the two groups were significantly separated. Distance-based redundancy analysis (db-RDA) suggested that soil pH and electrical conductivity (EC) had a positive relationship with the microbes in organic paddy soils. There were 23 amplicon sequence variants (ASVs) that showed differential abundance. Among them, g_B1-7BS (Proteobacteria), s_Sulfuricaulis limicola (Proteobacteria), g_GAL15 (p_GAL15), c_Thermodesulfovibrionia (Nitrospirota), two of f_Anaerolineaceae (Chloroflexi), and two of g_S085 (Chloroflexi) showed that they were more abundant in organic soils, whereas g_11-24 (Acidobacteriota), g__Subgroup_7 (Acidobacteriota), and g_Bacillus (Firmicutes) showed differential abundance in nonorganic paddy soils. Functional prediction of microbial communities in paddy soils showed that functions related to carbohydrate metabolism could be the major metabolic activities. Our work indicates that organic farming differs from nonorganic farming in terms of microbial composition in paddy soils and provides specific microbes that might be helpful for understanding soil fertility.

Impacts of a Commercially Available Horticultural Oil Biopesticide (EF-400) on the Tomato-Phytophthora infestans Pathosystem.

Biopesticide fungicides are naturally derived compounds that offer protection from plant diseases through various modes of action, including antimicrobial activity and upregulation of defense responses in host plants. These plant protectants provide a sustainable and safe alternative to conventional pesticides in integrated disease management programs and are especially salient in the management of high-risk and economically important diseases such as late blight of tomato and potato, for which host resistance options are limited. In this study, a commercially available biopesticide, EF400 comprised of clove (8.2%), rosemary (8.1%), and peppermint oils (6.7%) (Anjon AG, Corcoran, CA), was investigated for its effects on the Phytophthora infestans-tomato pathosystem. Specifically, we evaluated the impact of EF400 on P. infestans growth in culture, disease symptoms in planta, and activation of host defenses through monitoring transcript accumulation of defense-related genes. The application timing and use rate of EF400 were further investigated for managing tomato late blight. EF400 delayed the onset of tomato late blight symptoms, although not as effectively as the copper hydroxide fungicide Champ WG (Nufarm Americas Inc., Alsip, IL). Pathogen mycelial growth and sporangial quantity on late blight-susceptible tomato leaves were significantly reduced with EF400. The biopesticide also had an enhancing or suppressing effect on the transcript accumulation of three defense-related genes: Pin2, PR1a, and PR1b. Our work in exploring a commercially available horticultural oil biopesticide meaningfully contributed to the essential knowledge base for optimizing recommendations for the management of tomato late blight.

Changes in crop trait plasticity with domestication history: Management practices matter.

Crop domestication has led to the development of distinct trait syndromes, a series of constrained plant trait trade-offs to maximize yield in high-input agricultural environments, and potentially constrained trait plasticity. Yet, with the ongoing transition to organic and diversified agroecosystems, which create more heterogeneous nutrient availability, this constrained plasticity, especially in root functional traits, may be undesirable for nutrient acquisition. Such agricultural systems require a nuanced understanding of the soil-crop continuum under organic amendments and with intercropping, and the role crop genetic resources play in governing nutrient management and design. In this study, we use a functional traits lens to determine if crops with a range of domestication histories express different functional trait plasticity and how this expression changes with soil amendments and intercropping. We utilize a common garden experiment including five wheat (Triticum aestivum) varietals with a range of domestication histories planted in a factorial combination with amendment type (organic and inorganic) and cropping design (monoculture or intercropped with soybean). We use bivariate, multivariate and trait space analyses to quantify trait variation and plasticity in five leaf and five root functional traits. Almost all leaf and root traits varied among varieties. Yet, amendment type was nearly inconsequential for explaining trait expression across varieties. However, intercropping was linked to significant differences in root acquisitive strategies, regardless of the varietals' distinct history. Our findings show substantial leaf and root trait plasticity, with roots expressing greater trait space occupation with domestication, but also the strong role of management in crop trait expression. We underscore the utility of a functional trait-based approach to understand plant-soil dynamics with organic amendments, as well as the role of crop genetic histories in the successful transition to low-input and diversified agroecosystems.

Crossing the Old Local Breed Deutsches Lachshuhn with the Layer Breed White Rock: Effects on Laying Performance of the Females and Fattening Performance of the Males.

We tested the novel cross of the old local breed Deutsches Lachshuhn and the layer breed White Rock, as well as purebred Deutsches Lachshuhn, for their suitability as dual-purpose chickens under 100% organic husbandry conditions, and compared their performance and welfare with the two dual-purpose crosses New Hampshire × Bresse and Bresse × White Rock, which are already established in Germany. Chicks were reared in mixed-sex groups until slaughter of the males at 15 or 18 weeks of life. Data on laying performance and animal welfare were recorded until the hens' 72nd week of life. Laying performance of Deutsches Lachshuhn × White Rock was almost twice as high as that in purebred hens, while fattening performance of the males did not differ. Deutsches Lachshuhn × White Rock, New Hampshire × Bresse and Bresse × White Rock realized a balanced performance profile of 242-250 eggs per hen alive and a final live weight of the males of 2924-3105 g after 18 weeks of rearing. The efficiency of a pair of chickens (one male and one female) was very similar for the crosses (3.69-3.77 kg feed kg-1 marketable product), while purebred Deutsches Lachshuhn was less efficient (6.35 kg feed kg-1 marketable product). Crossing the breed Deutsches Lachshuhn with a layer breed therefore improved laying performance and overall efficiency of the birds compared to purebred Deutsches Lachshuhn.

Development of agroecology in Austria and Germany.

Background: Transforming food systems is necessary to address the global issues of severe biodiversity loss, hunger, and malnutrition as well as the consequences of the rapidly advancing climate change. Agroecology as a systemic approach has been recognised as a promising path of change exemplified in various case studies strengthening this transformation. The aim of this study is to get insight specifically for Austria and Germany in providing an overview of the advancement in agroecology in both countries and identify agroecology-related initiatives. Methods: 21 interviews with experts were conducted to determine the recognition, understanding, and development of agroecology in Austria and Germany in terms of movement, practice, policies, education, and research. In addition, information about agroecology-related initiatives was collected from interviews with 24 representatives of initiatives and literature analysis. Data was analysed according to five activity categories under which agroecology manifest: movement, practice, living lab, science and research infrastructure, and training and education. Results: Results show that the term agroecology is not commonly used in Austria and Germany, where the concept is mainly associated to a scientific discipline. Practices considered agroecological are implemented primarily through organic agriculture, which is very developed in Austria and to a lesser extent in Germany. Many networks, food policy councils, associations, and scientific projects related to agroecology exist, each with specific purposes and ambitions to change farming and food systems. While most selected initiatives do not explicitly refer to agroecology, all follow certain agroecological principles and aim at contributing to accelerate the agroecological transition. Conclusions: Clarifying the concept of agroecology, overcoming economic and political barriers as well as fostering participation of a multitude of stakeholders in the transition is essential for the future development of agroecology in Austria and Germany.

The Biostimulant, Potassium Humate Ameliorates Abiotic Stress in Arabidopsis thaliana by Increasing Starch Availability.

Potassium humate is a widely used biostimulant known for its ability to enhance growth and improve tolerance to abiotic stress. However, the molecular mechanisms explaining its effects remain poorly understood. In this study, we investigated the mechanism of action of potassium humate using the model plant Arabidopsis thaliana. We demonstrated that a formulation of potassium humate effectively increased the fresh weight accumulation of Arabidopsis plants under normal conditions, salt stress (sodium or lithium chloride), and particularly under osmotic stress (mannitol). Interestingly, plants treated with potassium humate exhibited a reduced antioxidant response and lower proline accumulation, while maintaining photosynthetic activity under stress conditions. The observed sodium and osmotic tolerance induced by humate was not accompanied by increased potassium accumulation. Additionally, metabolomic analysis revealed that potassium humate increased maltose levels under control conditions but decreased levels of fructose. However, under stress, both maltose and glucose levels decreased, suggesting changes in starch utilization and an increase in glycolysis. Starch concentration measurements in leaves showed that plants treated with potassium humate accumulated less starch under control conditions, while under stress, they accumulated starch to levels similar to or higher than control plants. Taken together, our findings suggest that the molecular mechanism underlying the abiotic stress tolerance conferred by potassium humate involves its ability to alter starch content under normal growth conditions and under salt or osmotic stress.

Physiological and biochemical characterization of biochar-induced resistance against bacterial wilt of eggplants.

The abrupt variation in climatic patterns has become a global concern in terms of food security. Biochar, known to ameliorate climatic adversities by sequestering carbon and activating systemic resistance pathways in plants, has become increasingly relevant. Therefore, the study was aimed to characterize leaf waste biochar (LWB) by Fourier-transform infrared spectroscopy, scanning electron microscopy with energy dispersive X-ray (SEM-EDX) and X-ray diffraction analytical techniques as well as determination of its impact on the development of bacterial wilt (BW) in eggplant (Solanum melongena) caused by Ralstonia solanacearum (RS). The effect of LWB on the physiology and defence-associated biochemistry of eggplants was investigated thoroughly. Eggplants either inoculated (+RS) or uninoculated (-RS) were cultivated in potting mixture containing 3 and 6% (v/v) LWB separately. In comparison with substrate (soil only), percentage disease index was significantly reduced (71%) in plants grown in 6% LWB-amended treatments. Biochar-induced increase in level of total chlorophyll content as well as in biochemicals such as phenolics, flavonoids and peroxidases were evident on plants in terms of resistance response against BW. Moreover, biochar also significantly affected the level of NPK in the eggplants. In conclusion, biochar-triggered biochemical alterations played a pivotal role in the management of BW along with the curing of the disease-infested soils.

The Effect of Imidacloprid on the Volatile Organic Compound Profile of Strawberries: New Insights from Flavoromics.

Organic agriculture is of great socioeconomic significance because it can promote the nutritional quality of horticultural crops and is environmentally friendly. However, owing to the lack of techniques for studying complex aroma-related chemical profiles, limited information is available on the influence of organic practices on the flavor quality of strawberries, one of the primary factors driving consumer preferences. Here, two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GC×GC-TOF-MS) and flavoromics analysis was employed to investigate the profiles and differences in the volatile organic compounds (VOCs) of strawberries under organic (without imidacloprid) and conventional (with imidacloprid) agricultural practices. A total of 1164 VOCs, representing 23 chemical classes (e.g., aldehydes, terpenes, and furanone compounds), were detected, which is the highest number of VOCs that have ever been detected in strawberries. The sensory evaluation results indicated that there was a notable influence of imidacloprid (IMI) on the aroma of the strawberries. Principal component analysis and partial least squares discriminant analysis results suggested that the composition of volatile compounds significantly differed in the present study between the IMI-treated and non-IMI-treated groups. Furthermore, the flavor-related indicators of 25 key contributors to the differences between the two treatment groups suggested that VOC profiles can be considered an indicator for distinguishing between strawberries from different agricultural practices. Flavoromics can provide new insights into the quality of strawberries from different agricultural practices.

Ideotype breeding for crop adaptation to low phosphorus availability on extensive organic farms.

Organic farming in extensive production regions, such as the Canadian prairies have a particularly difficult challenge of replenishing soil reserves of phosphorus (P). Organic grains are exported off the farm while resupply of lost P is difficult due to limited availability of animal manures and low solubility of rock organic fertilizers. As a result, many organic farms on the prairies are deficient in plant-available P, leading to productivity breakdown. A portion of the solution may involve crop genetic improvement. A hypothetical 'catch and release' wheat ideotype for organic production systems is proposed to (i) enhance P uptake and use efficiency but (ii) translocate less P from the vegetative biomass into the grain. Root traits that would improve P uptake efficiency from less-available P pools under organic production are explored. The need to understand and classify 'phosphorus use efficiency' using appropriate indices for organic production is considered, as well as the appropriate efficiency indices for use if genetically selecting for the proposed ideotype. The implications for low seed P and high vegetative P are considered from a crop physiology, environmental, and human nutrition standpoint; considerations that are imperative for future feasibility of the ideotype.

Determining the optimum mixture of three essential oils for potato sprout suppression at room temperature storage.

As a staple crop, potatoes (Solanum tuberosum) play an important role in meeting daily caloric needs. To ensure adequate supplies for year-round consumption, potato quality must be maintained throughout lengthy storage periods. Towards this end, potato sprouting during storage must be minimized. Due to changing regulations regarding chemical means of potato sprout suppression, increased focus has turned to alternative products including essential oils (EO) as sprout suppressants in recent years. The complex composition of various EOs promises numerous options for sprout suppression. Furthermore, blends of several EOs may achieve enhanced sprout suppressant properties if synergistic interactions are present. We evaluated Syzygium aromaticum, Artemisia herba-alba, and Laurus nobilis EOs and blends thereof as sprout suppressants in potato cultivar Ranger Russet stored at room temperature and also tested for their antifungal activity against Colletotrichum fragariae, a causal organism of anthracnose disease in strawberries including other vegetables and fruits. A. herba-alba EO was an effective sprout suppressant when used alone and suppressed sprouting over the 90-day storage period. Interactions between A. herba-alba and S. aromaticum affected sprout length whereas interactions between A. herba-alba and L. nobilis EOs affected sprout number. An optimum blend of 50% - 82.31% A. herba-alba, 17.69% - 50% L. nobilis, and 0% - 1.01% S. aromaticum EOs could more effectively minimize tuber sprout length and number than any of the three whole EOs used alone. Among these three EOs, only S. aromaticum EO showed antifungal activity against C. fragariae in bioautography assay. These results exhibit the potential of EOs blends as a novel tactic in potato sprout suppression as well as potential natural product-based fungicides in managing C. fragariae.

Oral Treatment with Plant-Derived Exosomes Restores Redox Balance in H2O2-Treated Mice.

Plant-derived exosomes (PDEs) are receiving much attention as a natural source of antioxidants. Previous research has shown that PDEs contain a series of bioactives and that their content varies depending on the fruit or vegetable source. It has also been shown that fruits and vegetables derived from organic agriculture produce more exosomes, are safer, free of toxic substances, and contain more bioactives. The aim of this study was to investigate the ability of orally administered mixes of PDE (Exocomplex®) to restore the physiological conditions of mice treated for two weeks with hydrogen peroxide (H2O2), compared with mice left untreated after the period of H2O2 administration and mice that received only water during the experimental period. The results showed that Exocomplex® had a high antioxidant capacity and contained a series of bioactives, including Catalase, Glutathione (GSH), Superoxide Dismutase (SOD), Ascorbic Acid, Melatonin, Phenolic compounds, and ATP. The oral administration of Exocomplex® to the H2O2-treated mice re-established redox balance with reduced serum levels of both reactive oxygen species (ROS) and malondialdehyde (MDA), but also a general recovery of the homeostatic condition at the organ level, supporting the future use of PDE for health care.

Are Bacillus thuringiensis strains like any other Bacillus cereus strains? Phenotypic-based tools to locate Bacillus thuringiensis in the diversity of the Bacillus cereus sensu lato group.

Some Bacillus thuringiensis (Bt) strains are used as pesticide agent. This species belongs to Bacillus cereus (Bc) group which contains many species with a high phenotypic diversity, and could be pathogenic like B. cereus. The aim of this study was to characterize the phenotype of 90 strains belonging to Bc group, half of which were Bt. Knowing that Bt strains belong to different phylogenetic Bc groups, do Bt strains have the same phenotype than other Bc group strains? Five phenotypic parameters were estimated for 90 strains in the Bc group, of which 43 were Bt strains: minimal, maximal and optimal growth temperature, cytotoxicity on Caco-2 cells, heat resistance of spores. The dataset was processed by principal component analysis, showing that 53% of the variance of the profiles corresponded to factors linked to growth, heat resistance and cytotoxicity. The phenotype followed the phylogenetic groups based on panC. Bt strains showed similar behavior to other strains in the Bc group, in our experimental conditions. Commercial bio-insecticide strains were mesophilic with low heat resistance.

The endophytobiome of wild Rubiaceae as a source of antagonistic fungi against the American Leaf Spot of coffee (Mycena citricolor).

AIMS: The American leaf spot, caused by Mycena citricolor, is an important disease of coffee (Coffea arabica), mostly in Central America. Currently, there are limited pathogen control alternatives that are environment friendly and economically accessible. The use of fungi isolated from the plant endomycobiota in their native habitats is on the rise because studies show their great potential for biological control. To begin to generate a green alternative to control M. citricolor, the objectives of the present study were to (i) collect, identify, screen (in vitro and in planta), and select endophytic fungi from wild Rubiaceae collected in old-growth forests of Costa Rica; (ii) confirm endophytic colonization in coffee plantlets; (iii) evaluate the effects of the endophytes on plantlet development; and (iv) corroborate the antagonistic ability in planta. METHODS AND RESULTS: Through in vitro and in planta antagonism assays, we found that out of the selected isolates (i.e. Daldinia eschscholzii GU11N, Nectria pseudotrichia GUHN1, Purpureocillium aff. lilacinum CT24, Sarocladium aff. kiliense CT25, Trichoderma rifaii CT5, T. aff. crassum G1C, T. aff. atroviride G7T, T. aff. strigosellum GU12, and Xylaria multiplex GU14T), Trichoderma spp. produced the highest growth inhibition percentages in vitro. Trichoderma isolates CT5 and G1C were then tested in planta using Coffea arabica cv. caturra plantlets. Endophytic colonization was verified, followed by in planta growth promotion and antagonism assays. CONCLUSIONS: Results show that Trichoderma isolates CT5 and G1C have potential for plant growth promotion and antagonism against Mycena citricolor, reducing incidence and severity, and preventing plant mortality.

Testing the role of allelochemicals in different wheat cultivars to sustainably manage weeds.

BACKGROUND: Selecting wheat varieties with allelopathic potential or high competitiveness against weeds is a sustainable solution for organic farming to eliminate the use of synthetic herbicides. Wheat is one of the most economically important crops. This study focuses on screening the allelopathic or competitive potential of four wheat cultivars, Maurizio, NS 40S, Adesso and Element, on two weeds of interest due to acquired herbicide resistance, Portulaca oleracea and Lolium rigidum, through germination and growth bioassays and the identification and quantification of benzoxazinoids (BXZs) and polyphenols (phenolic acids and flavonoids). RESULTS: The different cultivars showed different abilities to manage surrounding weeds and different capacity to exude or accumulate specialized metabolites in the presence of those weeds. Furthermore, each cultivar behaved differently depending on the weed present in the medium. The most efficient cultivar to control the tested monocot and dicot weeds was Maurizio, as it effectively controlled germination and growth of L. rigidum and P. oleracea while exuding large amounts of benzoxazinones through the roots, especially the hydroxamic acids 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one and dihydroxy-2H-1,4-benzoxaxin-3(4H)-one. By contrast, NS 40S, Adesso and Element showed the potential to control the growth of just one of the two weeds through allelopathy or competition. CONCLUSION: This study reveals that Maurizio is the most promising wheat cultivar for sustainable weed control, and that the screening of crop varieties with allelopathic potential, which results in the displacement of synthetic herbicides, is an immediate solution in ecological and sustainable agriculture. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.