Search Results (279)

Protecting the soil ecosystem’s functioning is one of the main goals of recent regulations of chemicals. It is important to take soil biodiversity into account when designing cropping systems and measuring their impacts. Our main objective was to evaluate the effects of an organic amendment on soil nematode biodiversity compared to two years of fumigation. The plot-trial was conducted on tomato and lettuce plants under greenhouse, and free-living nematodes were used as bio-indicators of soil health. Treatments included a soil fumigant (applied once or twice over time), water control, and an organic substance. Soil samplings were carried out to determine the Meloidogyne incognita reproduction factor and the soil nematode community analysis using soil biological indicators. Data showed that soil fumigation clearly made the soil increasingly dependent on chemicals. Furthermore, fumigants suppressed pests and pathogens as well as their natural antagonists, causing a lack of biodiversity. While soils treated with organic matter respond slowly to stressors, they are progressively more suppressive thanks to biodiversity enrichment. Nematodes have proven to be useful indicators of the soil biota in response to biotic or abiotic disturbances. Their species richness and functional diversity make them valid bioindicators of soil management impact. Full article

The use of chloride-based deicing salts, particularly sodium chloride (NaCl) and calcium chloride (CaCl₂), is a common practice in cold regions for maintaining road safety during winter. However, the accumulation of salt residues in adjacent soils poses serious environmental threats, including reduced pH, increased electrical conductivity (EC), disrupted soil structure, and plant growth inhibition. This study aimed to evaluate the combined effect of activated carbon (AC) and Pennisetum alopecuroides, a salt-tolerant perennial grass, in alleviating salinity stress under deicer-treated soils. A factorial greenhouse experiment was conducted using three fixed factors: (i) presence or absence of Pennisetum alopecuroides, (ii) deicer type (NaCl or CaCl₂), and (iii) activated carbon mixing ratio (0, 1, 2, 5, and 10%). Soil pH, EC, and ion concentrations (Na⁺, Cl⁻, Ca²⁺) were measured, along with six plant growth indicators. The results showed that increasing AC concentrations significantly increased pH and reduced EC and ion accumulation, with the 5% AC treatment being optimal in both deicer systems. Plant physiological responses were improved in AC-amended soils, especially under CaCl₂ treatment, indicating less ion toxicity and better root zone conditions. The interaction effects between AC, deicer type, and plant presence were statistically significant (p < 0.05), supporting a synergistic remediation mechanism involving both adsorption and biological uptake. Despite the limitations of short-term controlled conditions, this study offers a promising phytomanagement strategy using natural adsorbents and salt-tolerant plants for sustainable remediation of salt-affected soils in road-adjacent and urban environments. Full article

A mutation affecting eye color was discovered in Macrolophus pygmaeus (Rambur) (Hemiptera: Miridae). This species is an important biological control agent used to manage whiteflies and other arthropod pests in greenhouse crops. Typically, these predators exhibit a dark eye coloration, ranging from garnet to black. However, individuals with bright red eyes have been identified within wild populations, making them easily distinguishable. The objective of this study was to study the mode of inheritance of the red eye color mutation observed. Additionally, a comparative analysis of key biological traits was conducted between individuals carrying the mutation and those from a wild-type population. From these specimens, a population carrying this eye color mutation, referred to as ruby, was established. Genetic analyses revealed that the red coloration is controlled by a single recessive allele located on an autosomal chromosome. Red-eyed individuals exhibited superior performance in biological traits, including greater body size in both males and females, as well as increased fecundity and longevity in females. The utilization of this red-eyed variant could be valuable as a visual marker in ecological and biological studies of population dynamics. Full article

Alternative plant protection methods should be promoted to mitigate the dangers and consequences of using chemical pesticides, ensuring a safe environment and protecting human health (Directive 2009/128/EC). One of the objectives of the EU organic production action plan is to provide substitutes for plant protection methods, decrease the adverse effects on the environment, and promote the diversity of living organisms. The use of synthetic and non-organic chemicals has significantly expanded, damaging human health and the environment. This study aimed to evaluate alternative plant protection solutions for the improvement of the strawberry cv. Elsanta plant’s generative development, yield, fruit quality, and biochemical composition. The two-year strawberry experiment conducted in a tunnel greenhouse included chemical and biological means (Bacteria and Thyme preparations). The experiment randomised a block design with four replicates and 32 plants per replicate. The treatments were conducted at the 10% flowering state (BBCH 61–65), every 7–10 days (a total of four times): (1) Control, (2) Chemical, (3) Bacteria, and (4) Thyme. We evaluated the yield, fruit weight, size, number of leaves, crowns, flowers, inflorescences, fruit firmness, soluble solids, and Vitamin C. The highest fruit weight at the first picking was in the Bacteria treatment. The number of rotten fruits was similar after all treatments. Additionally, they were firmer and bigger in size but had a smaller soluble solids content. The strawberry ascorbic acid and soluble solids content (Brix %) showed significant variation. The highest ascorbic acid concentration in the fruit was after the Thyme application (45.06%). Our study showed that alternative plant protection measures can reduce the use of chemical fungicides and maintain proper fruit quality. Full article

Nucleopolyhedroviruses of lepidopteran larvae (Alphabaculovirus, Baculoviridae) form the basis for effective and highly selective biological insecticides for the control of caterpillar pests of greenhouse and field crops and forests. Horizontal transmission is usually achieved following the release of large quantities of viral occlusion bodies (OBs) from virus-killed insects. In the present review, I examine the evidence for productive midgut infection in different host species and the resulting transmission through the release of OBs in the feces (frass) of the host. This has been a neglected aspect of virus transmission since it was initially studied over six decades ago. The different host–virus pathosystems vary markedly in the quantity of OBs released in feces and in their ability to contaminate the host’s food plant. The release of fecal OBs tends to increase over time as the infection progresses. Although based on a small number of studies, the prevalence of transmission of fecal inoculum is comparable with that of recognized alternative routes for transmission and dissemination, such as cannibalism and interactions with predators and parasitoids. Finally, I outline a series of predictions that would affect the importance of OBs in feces as a source of inoculum in the environment and which could form the basis for future lines of research. Full article

Fire blight, a devastating bacterial disease caused by Erwinia amylovora, has posed significant challenges to apple and pear production for over a century. This study introduces a gliding filamentous bacterium, the strain NSD29, isolated from natural forest soil in Xinjiang, China, as a biological control agent for managing this disease. Comprehensive characterization based on morphological, physiological, biochemical, 16S rRNA gene, and whole-genome analyses identified the strain NSD29 as Herpetosiphon llansteffanensis. The train NSD29 demonstrated potent predatory activity against E. amylovora in vitro. Its biocontrol efficacy was subsequently evaluated on detached leaves, inflorescences, young fruit, and shoots of fragrant pear under controlled greenhouse conditions. Results indicated that applying H. llansteffanensis NSD29 significantly inhibited lesion expansion on pear leaves and young fruit, achieving protective efficacies of 75.2% and 72.0%, respectively. Furthermore, pre-treatment spraying with NSD29 effectively reduced the incidence of blossom blight, with a control efficacy of 61.2%. On detached pear shoots, the application of NSD29 fermentation broth suppressed lesion expansion, demonstrating substantial protective (86.8%) and curative (75.6%) efficacies. This research provides the first evidence for the potential of Herpetosiphon species in the biological control of plant diseases, highlighting H. llansteffanensis NSD29 as a promising candidate for developing strategies to combat fire blight. Full article

The tomato russet mite (TRM), Aculops lycopersici, is a destructive pest of tomato crops worldwide. It poses a significant challenge to growers in both greenhouse and open-field conditions. Traditional chemical control methods are often ineffective, promote resistance, and have negative environmental impacts. This has prompted the search for alternative strategies, such as biological control and eco-friendly botanical pesticides. In this study, we evaluated the acaricidal effects of essential oils (EOs) extracted from three officinal plants, Origanum vulgare L., Salvia rosmarinus Spenn., and Salvia officinalis L., cultivated using precision aromatic crop (PAC) techniques. Their efficacy was evaluated against A. lycopersici under laboratory conditions. The chemical composition of the EOs was determined by solid-phase microextraction (SPME) coupled with gas chromatography–mass spectrometry (GC-MS). The dominant component of O. vulgare EO was carvacrol (83.42%), followed by ρ-cymene (3.06%), and γ-terpinene (2.93%). In S. rosmarinus, α-pinene (28.0%), 1,8-cineole (11.00%), and borneol (7.72%) were the major components. S. officinalis EO was characterized by high levels of 1,8-cineole (27.67%), camphor (21.91%), and crisantenone (12.87%). We tested multiple concentrations (320–5000 μL L−¹) and exposure times (1–4 days) to assess mite mortality. The results revealed both dose- and time-dependent toxic activity, with significant differences among EOs. O. vulgare EO was the most toxic, causing 90% mortality at 0.5% (w/v) concentration after 4 days. S. rosmatinus and S. officinalis EOs had more limited effects, with 46% and 42% mortality, respectively. Lethal concentration (LC₅₀) values were 2.23 mL L−¹ (95% CI: 1.74–3.05) for O. vulgare, 5.84 mL L−¹ (95% CI: 3.28–22.29) for S. rosmarinus, and 6.01 mL L−¹ (95% CI: 2.63–261.60) for S. officinalis. These results indicate that O. vulgare EO shows efficacy comparable to commercially available botanical pesticides. Our findings support the potential of O. vulgare EO as a viable alternative for the control of A. lycopersici, contributing to integrated pest management (IPM) strategies. Full article

The tarnished plant bug, Lygus lineolaris Palisot de Beauvois (Hemiptera: Miridae), is an economically important pest of row crops worldwide. Ten isolates of entomopathogenic nematodes (EPNs) (Rhabditida: Steinernematidae and Heterorhabditidae) were evaluated against the third instar nymphal stage of the tarnished plant bug and its generalist predator, the sculpted damsel bug, Nabis roseipennis Reuter (Hemiptera: Nabidae), one of the most abundant and commonly encountered damsel bugs in cotton and soybean agroecoscapes across the Southeastern United States. The objectives of these experiments were to assess the infectivity of entomopathogenic nematodes (EPN) by direct topical exposure against the sculpted damsel bug and tarnished plant bug, whether the predator prey choice is affected by EPN infection, and if feeding on EPN-infected tarnished plant bug (TPB) prey items could result in cross-infection of the predator. Mortality rates at a concentration of 200 infective juveniles (IJs)/mL significantly differed among isolates and insect species, ranging from 30% to 93% for tarnished plant bugs and from 6% to 38% for sculpted damsels, respectively. The third instars of L. lineolaris were more susceptible to the ten nematode isolates than N. roseipennis. Higher pathogenicity on the tarnished plant bug and a low mortality potential make strains HbHP88, HbVS, Sc17c+e, and SfSN the most promising candidates for the biological control of L. lineolaris under lab and greenhouse conditions while preserving beneficial predators of the Southeastern United States. Full article

At Qinghai agriculture districts, Evergestis extimalis poses a significant threat to spring rapeseed cultivation through its larvae burring into the rapeseed kernels and feeding seeds. To protect the ecological environment of the Qinghai–Tibet Plateau, it is essential to research and develop biological control technologies for pest management. In this study, we isolated and purified a new entomopathogenic fungus from the carcasses of E. extimalis larvae, which was identified as Mucor hiemalis based on morphological characteristics combined with ITS rDNA and 18S rDNA sequence analyses. Subsequently, the optimal growth conditions for the strain were determined as follows: SDAY medium, fructose as the carbon source, peptone as the nitrogen source, 25 °C, pH 6.0–7.0, and a 0:24 (light:dark) photoperiod.However, UV can significantly reduce fungal spore production. The bioassay result shows its pathogenicity was a concentration-dependent effect on E. extimalis, and younger larvae were more susceptible. With 1 × 10⁸ spores/mL inoculated, survival of second instar larvae decreased by the greenhouse pot experiment. In conclusion, M. hiemalis exhibits a significant biocontrol potential against E. extimalis. Full article

Verticillium spp. are soil-borne fungal pathogens capable of infecting over 400 plant species via their root systems, with each species demonstrating a distinct host range. The primary host of Verticillium nonalfalfae is the hop plant (Humulus lupulus), which becomes affected by Verticillium wilt and, in severe cases, dieback. A dual screening approach was employed to isolate Streptomycetes as potential biocontrol agents from the hop root systems alongside other bacterial species from hop xylem. Three Pseudomonas strains from the xylem and three Streptomyces strains from the roots were selected based on their in vitro antifungal activity against Verticillium dahliae and/or V. nonalfalfae. Their potential for controlling Verticillium wilt was further assessed through in planta assays conducted under greenhouse conditions. The results demonstrated that Pseudomonas sp. HX1, Streptomyces luteogriseus HR40, and Streptomyces flavofungini HR77 significantly reduced the disease severity index by 32.56% compared to artificially infected control plants. In contrast, the commercial biocontrol product Serenade^® ASO, containing Bacillus amyloliquefaciens QST 713, achieved a reduction of 13.96%. These findings underscore the potential of the selected bacterial strains as promising candidates for the biological control of Verticillium wilt in hops affected by V. nonalfalfae. Full article

Soil phosphorus is heavily restricted by soil acidification and salinization. There is a need to determine a biological solution for this issue to replace the overuse of chemical phosphorus fertilizer that aggravates adverse conditions, such as salinity, acidity, and metallic toxicity. Therefore, this study aimed at determining the phosphorus dynamics in terms of the soil, growth, and yield of rice under the supplementation of phosphate (P)-solubilizing purple nonsulfur bacteria (PNSB), Cereibacter sphaeroides ST16 and ST26, in salinized soil collected from An Bien district, Kien Giang province, Vietnam, under greenhouse conditions. The experiment followed a completely randomized block design with two factors and four replications. In particular, the reduced percentages of P fertilizer (A) were 0%, 25%, 50%, 75%, and 100% P. The supplementations of C. sphaeroides strains (B) were the negative control, ST16, ST26, and a mixture of both ST16 and ST26. The results showed that supplying the C. sphaeroides ST16 and ST26 reduced the insoluble P content by 10.1–10.6% Fe-P, 10.3–12.2% Ca-P, and 12.7–43.1% Al-P and increased available P by 8.33–27.8%, leading to total P uptake in plants increasing by 29.4–56.1%. The C. sphaeroides strains also reduced soil Na⁺. Therefore, supplying the C. sphaeroides strains increased the rice growth and yield components of rice, leading to a greater yield of 26.5–51.0%. Supplying each strain of ST16 and ST26 reduced 50–100% P fertilizer as recommended. Ultimately, inoculation of the bacterial mixture allowed a reduction by 100% P fertilizer percentage as recommended but the yield remained the still. Full article

Bemisia tabaci is a major agricultural pest that affects both greenhouse and field crops by feeding on plant sap, which impairs plant growth, and by secreting honeydew, promotes sooty mold growth that further reduces photosynthesis. Additionally, these insects are vectors for viruses such as the cucurbit chlorotic yellows virus (CCYV), which causes significant damage to cucurbit crops. Traditional chemical pesticide treatments have limitations, including the development of resistance, harm to non-target organisms, and environmental contamination. Traditional chemical pesticides have limitations when it comes to controlling plants infested by CCYV and whitefly. However, the underlying reasons for these limitations remain unclear, as does the impact of entomopathogenic fungi on whitefly responses. This study explores the potential of using biological control agents, specifically Beauveria bassiana and Purpureocillium lilacinum, to manage whitefly populations and control CCYV transmission. Laboratory experiments were conducted to evaluate the pathogenicity of these fungi on non/viruliferous whitefly. The results indicated that both fungi effectively reduced whitefly populations, with B. bassiana showing particularly strong adverse effects. Whiteflies infected with CCYV exhibited a higher LC₅₀ to B. bassiana and P. lilacinum. Furthermore, bio-pesticides significantly altered the bacterial microbiome dynamics of the whitefly. Interestingly, CCYV increased the susceptibility of whiteflies to entomopathogenic fungus. The findings suggest that these biocontrol agents offer a sustainable alternative to chemical pesticides. Our study unraveled a new horizon for the multiple interaction theories among bio-pesticides–insects–symbionts–viruses. Full article

Global challenges such as soil degradation and water scarcity necessitate sustainable agricultural practices, particularly in regions where saline water is increasingly used for irrigation. This study investigates the effects of four compost treatments, including surface-applied mulch compost (MC), Johnson–Su biologically active compost incorporated into soil (JCI), mulch compost incorporated into soil (MCI), and no compost as control (NC), on soil fertility, microbial activity, and Capsicum annuum (chili pepper) growth. Greenhouse experiments were conducted using soil from two different sites (New Mexico State University’s (NMSU) agricultural research plots and agricultural field-testing site at the Brackish Groundwater National Desalination Research Facility (BGNDRF) in Alamogordo, New Mexico) and two irrigation water salinities (brackish at ~3000 µS/cm and agricultural at ~800 µS/cm). The Johnson–Su compost treatment demonstrated superior performance, due to its high soil organic matter (41.5%), nitrate (NO₃⁻) content (82.5 mg/kg), and phosphorus availability (193.1 mg/kg). In the JCI-treated soils, microbial biomass increased by 40%, and total microbial carbon reached 64.69 g/m² as compared to 64.7 g/m² in the NC. Plant growth parameters, including chlorophyll content, root length, and wet biomass, improved substantially with JCI. For instance, JCI increased plant height by 20% and wet biomass by 30% compared to NC treatments. The JCI treatment also effectively mitigated soil salinity, reducing Na⁺ accumulation by 60% and Cl⁻ by 70% while enhancing water retention and soil structure. Principal Component Analysis (PCA) revealed a distinct clustering of JCI treatments, demonstrating its ability to increase nutrient retention and minimize salinity stress. These results indicate that biologically active properties, such as fungi-rich compost, are critical to providing an effective, environmentally resilient approach for enhancing soil fertility and supporting sustainable crop production under brackish groundwater irrigation, particularly in regions facing freshwater scarcity. Full article

The rapid expansion of the cannabis industry in Canada post-legalization has heightened the prevalence of pests, particularly the cannabis aphid Phorodon cannabis (P. cannabis), which poses significant threats to crop health. This study investigates the immediate effects of P. cannabis on Cannabis sativa (C. sativa) plants and explores biological control strategies utilizing entomopathogenic fungi. Fungal isolates of Beauveria bassiana and Metarhizium anisopliae were isolated from infected aphids, cultured, and characterized. Infection tests on aphids revealed that both fungi achieved 100% aphid mortality at high conidial concentrations (1 × 10⁷ conidia/mL) by the 10th DAT, with Beauveria bassiana demonstrating better efficacy. In greenhouse trials on three cannabis varieties, B. bassiana effectively controlled aphid populations, keeping levels low and stable in infested plants treated with B. bassiana at the concentration of 1 × 10⁷ conidia mL⁻¹ (I-B) and infested plants treated with insecticide (I-I). Both I-B and I-I treatments maintained aphid populations near zero for nine weeks. In contrast, control plants showed significant aphid growth, with the Perseid variety being the most susceptible, followed by Congo Durban, while GCC exhibited the lowest susceptibility. Cannabinoid and terpene analyses revealed that treatment with insecticide substantially decreased the amount of produced cannabinoids and terpenes. In contrast, Beauveria bassiana-treated plants exhibited higher concentrations of key metabolites, including delta-9-tetrahydrocannabinolic acid and cannabidiolic acid, and total terpenes, compared to chemically treated plants, and in two out of three cultivars, these concentrations were higher than in control, untreated plants. The findings highlight Beauveria bassiana as an eco-friendly alternative for pest management that not only controls aphids effectively but also supports the biochemical quality of cannabis plants. Full article

A greenhouse trial was conducted in Southern Italy to examine the effects of foliar applications of two substances, methyl-jasmonate (MeJA) and a zeolite, on the harvest and post-harvest performance of two hydroponically grown baby leaf genotypes (leafy chicory ‘Cicoria costa rossa’; kale ‘Cavolo nero’). MeJA is a phyto-hormone primarily studied for fruit and post-harvest applications, while zeolite is typically used for pest and disease biological control. MeJA (Sigma-Aldrich Merck KGaA, Darmstadt, Germany), and a commercial zeolite (Big-Zeo, Agricola Internazionale s.r.l., Pisa, Italy) (BigZeo) were sprayed twice at the second and fourth true leaf stages (BigZeo, 5 kg ha⁻¹; MeJA, 250 µM). Bio-physiological (yield, dry matter DM, chlorophyll CHL, weight loss WL) and qualitative (nitrate, carotenoids, phenols, flavonoids, anthocyanins, antioxidant activity) traits were evaluated in both raw and fresh-cut (7 day-cold-stored) products. Treatments did not significantly affect yield (1.0 kg m⁻²), while plant responses to the substances concerning other traits were genotype-dependent. MeJA enhanced greenness (CHL), texture (DM), and antioxidant activity (by increasing carotenoids and flavonoids) in chicory. In contrast, zeolite improved greenness, texture, and antioxidant activity (by increasing carotenoids, anthocyanins, and phenols), and reduced nitrate in kale. Treatments did not affect weight loss (2.2 g 100 g⁻¹ f.w., on average). After 7 days of storage, MeJA-treated chicory and zeolite-treated kale exhibited improved textural and nutritional quality. Full article