Gesunde Pflanzen最新文献

The use of inorganic amendments to immobilize cadmium is an eco-friendly approach. The present study aimed to evaluate sulfur nanoparticles (SNPs) for the mitigation of Cd stress in saffron (Crocus sativus L.). A factorial layout based on a completely randomized design with four replications was conducted in greenhouse conditions. Treatments consisted of Cd concentration (0, 15, 30, and 45 mg kg⁻¹) and sulfur amendments (control, SNPs, and bulk sulfur particles (BSPs) at 100 and 200 mg kg⁻¹). In non-contaminated plants, application of BSPs 200 increased stigma and flower dry weight by 127 and 108%, respectively. At Cd 30 mg kg⁻¹, using BSPs 100 yielded the highest stigma and flower dry weight. More daughter corms were produced by using BSPs 100 in control plants and BSPs 200 or SNPs 100 in 45 mg kg⁻¹ Cd. The highest root dry weight measured in Cd 15 mg kg⁻¹ + SNPs 100 and Cd 45 mg kg⁻¹ + SNPs 200. The fertilization effect of BSPs 200 was reflected in the dry weight of the leaf, daughter corms, root, and daughter corm diameter. Roots accumulated the highest Cd concentration, followed by leaves, corms, and stigma. The bioconcentration factor (BCF) in plant tissues was in descending order (BCFroot > BCFleaves > BCFcorm > BCFstigma). The highest total Cd accumulation was detected in 45 mg kg⁻¹ Cd along with SNPs 200. Overall, saffron seemed to be capable of phytostabilizing in managing Cd toxicity by lowering its translocation to aboveground tissues, especially to the stigma.

Substantial economic losses of crops occur annually because of abiotic and biotic stresses that affect crop plants. Microbial volatile compounds (MVCs) are promising candidates for use in agriculture owing to their ability to constrain phytopathogens, induce resistance, and promote plant growth. Application of commercial synthetic insecticides and fungicides can damage the environment and adversely affect human health. In recent years, the use of MVCs to control plant diseases in vegetables and fruits has become an attractive alternative to synthetic chemicals. MVCs possess antifungal and insecticidal properties, which can be used to control plant diseases caused by phytopathogenic fungi and insects. MVCs also promote plant growth and help plants to combat adverse stress conditions. This review summarizes the importance of volatiles emitted by various microorganisms as well as recent advances in understanding the antifungal mechanisms adopted by MVCs and their use in agriculture to promote crop productivity.

Eco-friendly strategies, including botanical insecticides, can contribute to stored products Integrated Pest Management (IPM) programs as alternatives to chemical insecticides. Thus, this study investigated the chemical composition and the fumigant insecticidal activity of the essential oil (EO) from Pimenta pseudocaryophyllus (Myrtaceae) leaves against adults of Mexican bean weevil, Zabrotes subfasciatus (Coleoptera: Chrysomelidae: Bruchinae), an important insect pest of stored beans in tropical conditions. In addition, the contribution of EO’s major compounds and binary mixtures on overall fumigant insecticidal activity against this pest was also assessed. Based in the GC-MS analysis, the phenylpropanoids chavibetol (39.60%) and methyl eugenol (9.10%) and the monoterpenoids 1,8-cineole (13.89%) and terpinolene (8.19%) were identified as major components. After 72 h of exposure, the EO showed promising insecticidal fumigant activity against Z. subfasciatus with a strong interaction effect of sex (LC₅₀: 280.17 and 86.63 µL L⁻¹ of air, respectively for females and males). When tested at their relative concentration in the crude EO, the phenylpropanoids chavibetol, methyl eugenol and the monoterpenoid 1,8-cineole as well as their binary mixtures caused the total mortality of exposed weevils, being equitoxic to a phosphine-based formulation used as a positive control. Thus, the EO from P. pseudocaryophyllus leaves is a promising fumigant insecticide to Z. subfasciatus management and its major compounds chavibetol, methyl eugenol and 1,8-cineole may be used to develop efficient and inexpensive artificial blends to IPM of stored beans.

Salinity is a major abiotic stress that can affect plant growth and development adversely. However, there is bare knowledge about its role in the quality of the seeds obtained from the plants that are grown under salinity. The present study aimed to explore the effect of salinity stress (control (0.7), 3.5, and 7 dS m⁻¹) on the seed germination parameters, 1000-seed weight, plant growth, and proline content of pepper (Capsicum annuum L.) genotypes (Maras, Carliston, and Dolmalik) in the greenhouse in 2018. The results showed that salinity stress significantly affected pepper genotypes, but their response to salinity stress was different. In this respect, the Maras genotype showed the highest proline content, leaf area, and plant biomass and showed tolerance to salinity stress relative to the other genotypes. Concerning seed germination rates, Carliston and Dolmalik experienced severe reductions of 60 and 68%, respectively, under 7 dS m⁻¹ salinity level compared to the control, while the Maras genotype showed a mild drop of 27%. At a higher salinity level of 7 dS m⁻¹, there was a negative impact on 1000-seed weight, resulting in reductions of 20.73%, 36.12%, and 34.39% in Maras, Carliston, and Dolmalik, respectively. Importantly, the study findings underscored that salinity stress had a less severe adverse effect on the seed germination parameters and 1000-seed weight of the Maras genotype compared to the other genotypes, signifying its heightened tolerance to salinity. Furthermore, the present findings revealed that a reduction in both plant growth and biomass during the vegetative growth phase exerts adverse effects on seed weight and seed germination parameters. Moreover, the research identified the Maras as a salinity-tolerant genotype, which makes it a potential candidate for breeding programs.

Intensive potato cultivation affects weed species composition by selecting dominant and competitive weeds that represent a constraint of potato productivity. Field experiments were conducted during 2015 and 2016 growing seasons to examine the effects of soil tillage (plowing (PL), spading (SM), sub soiling (SS)) and fertilizer source (mineral (Min) and organic (Org)) on potato yield and weed community under Mediterranean environment. A randomized complete block design with three replications was adopted. Weed density and biomass were measured at the potato harvesting time. Weed density was highest in SS, intermediate in SM, and lowest in PL (43.8, 40.3, and 28.8 plants m⁻²). Similar trend was observed in weed biomass. Weed density and biomass were higher in Org than Min (42.1 vs. 36.4 plants m⁻² and 129.6 vs. 117.9 g m⁻², respectively). Perennial, monocot, and dicot weed species were the most abundant in subsoiling (13.1, 9.3 and 34.5 plants m⁻²). Density of perennial and dicot species were higher in Org than Min. Monocots were mostly linked with Min, while dicots were mainly associated with Org. Although tuber yield was higher in PL and Min (481.9 and 627.5 g m⁻² of DM), it was affected by growing season and might be associated to SM and Org. Although the study shows that increased weed biodiversity in the system, achieved with more sustainable practices, proves to be an obstacle to potato production, the adoption of spading machine applied in combination with mineral and organic fertilizers could be a valid alternative to plowing. Further studies are required to develop sustainable agricultural techniques able to improve the competitive capacity of crops and reduce the selection of dominant weed species.

Target spot, caused by Corynespora cassiicola, is an important leaf disease affecting cucumber plants, and alternative management studies are essential for the economic viability of this crop. Silicates were evaluated for the control of target spot and its pathogen, and the biochemical responses of plants were characterized. Preventive spraying was performed three times, at weekly intervals, with K₂SiO₃ + Cu and K₂SiO₃, at the concentrations 0, 28, 56, 84 and 112 mg L⁻¹ silicon (Si). Assessments included mycelial growth and germination in vitro; disease severity; number and diameter of lesions; pathogen sporulation on leaves; activities of the enzymes peroxidase, polyphenol oxidase and β‑1,3‑glucanase, and leaf levels of phenolic compounds. The application of Si-based sources had no effect in vitro, nor did it affect lesion diameter and sporulation. Disease severity was lowest after five days of inoculation for treatments with 56 and 84 mg L⁻¹ Si, but there was no disease control after three and seven days. The number of lesions was smallest from 28 to 112 mg L⁻¹ Si, after five days of inoculation, and at 56 mg L⁻¹ Si after seven days of inoculation for the treatment K₂SiO₃ + Cu, as well as at 56 and 112 mg L⁻¹ Si after five days and at 84 and 112 mg L⁻¹ Si after seven days of inoculation for K₂SiO₃. In general, there were no differences between the tested silicates. Enzyme activities and phenolic compound levels were not influenced by Si. The reduction in the disease severity and in the number of lesions, even if dependent on Si concentration or day of evaluation, demonstrated the possible viability of Si in controlling cucumber target spot, especially after further studies.

Tomato production is significantly harmed by the interruption of fungal pathogens, i.e., Alternaria solani, the causal agent of early blight, which is responsible for substantial yield losses in tomato crops. In recent years, the application of silver-based green synthesized nanomaterials (AgNMs) has been documented as the best performer against various plant diseases. However, the knowledge about applying green-synthesized AgNMs for the management of early blight and its impact on the components of the antioxidant defense system, especially in tomatoes, still needs to be discovered. Therefore, in the current study, two green synthesized viz. wild gourd (Citrullus colocynthis) and rough cocklebur (Xanthium strumarium) AgNMs were applied at three different concentrations to check their efficacy against the early blight of tomatoes and the components of the antioxidant defense system of tomato plants. Results revealed that C. colocynthis-based AgNMs were found to be most effective and exhibited disease incidence of A. solani (22%) with a significant increase in tomato production (13%) along with the number of fruits/plants. Moreover, application of C. colocynthis-based AgNMs improved the concentration of ascorbic acid (1240, 997 µg/mL), total phenolic contents (950, 800 µg/mL), flavonoids (111, 88 mg/g), hydrogen peroxide (0.0013, 0.001 U/mg), amylase (110, 89 U/mL), chlorophyll a (0.31, 0.25 mg/g), chlorophyll b (0.22, 0.16 mg/g), and total chlorophyll (0.61, 0.50 mg/g) in treated plants of resistant and susceptible varieties of tomato respectively, than that of control. It is concluded that applying green synthesized AgNMs may be a viable alternative to synthetic chemicals for managing the early blight of tomatoes.