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[学术文献 ] Dissipation Pattern, Terminal Residues, and Risk Assessment of Flutriafol and Cyflufenamid in Grapes under Egyptian Field Conditions 进入全文
ACS Agricultural Science & Technology 期刊
This study evaluated the dissipation and terminal residue levels of flutriafol and cyflufenamid in grape berries and leaves under Egyptian field conditions. Using an optimized LC-MS/MS method, both fungicides were quantified with high recovery rates (97.65–104.34%) and low detection limits (0.001 mg·kg–1). The dissipation half-lives of flutriafol were 3.25 days in berries and 1.95 days in leaves, while cyflufenamid exhibited half-lives were 4.1 days in berries and 3.31 days in leaves. Terminal residues for flutriafol ranged from 0.087 to 0.785 mg·kg–1, and for cyflufenamid, they ranged from 0.010 to 0.085 mg·kg–1, both below Codex MRLs. Based on terminal residues, the dietary risk assessment revealed risk quotients (RQs) below 1, indicating minimal consumer risk. A preharvest interval (PHI) of 3–10 days for flutriafol and 1–3 days for cyflufenamid is recommended. This study provides crucial data to ensure the safe use of these fungicides in grape production.
[学术文献 ] Evaluation of Botanicals for Management of Piercing-Sucking Pests and the Effect on Beneficial Arthropod Populations in Tea Trees Camellia sinensis L O. Kuntze (Theaceae) 进入全文
Journal of Insect Science 期刊
The tea green leafhopper Empoasca onukii Matsuda (Hemiptera: Cicadellidae), the orange spiny whitefly, Aleurocanthus spiniferus (Quaintanca) (Hemiptera: Aleyrodidae), and the green plant bugs Apolygus lucorum Meyer-Dür (Hemiptera: Miridae) are the important piercing–sucking herbivores in tea trees Camellia sinensis (L.) O. Kuntze (Theaceae). The goal of this study was to evaluate the laboratory toxicities and field control efficacies of botanical insecticides including matrine, azadirachtin, veratrine, and pyrethrin to three tea pests. Via leaf-dip bioassay, toxicity tests with botanical insecticides indicated that there were significant differences between the LC50 values for botanical insecticides within the same insect species. Matrine had the highest toxicity to E. onukii, A. spiniferus, and A. lucorum with the LC50 values of 2.35, 13.10, and 44.88 mg/liter, respectively. Field tests showed that, among four botanical insecticides, matrine at dose of 9 g a.i. ha−1 can significantly reduce the numbers of E. onukii and A. spiniferus and the infestation of A. lucorum on the tea plants. Furthermore, botanical insecticides matrine and azadirachtin had no obvious influence on the coccinellids, spiders, and parasitoids densities in tea plantations. The results of this study indicated that use of botanical insecticides, such as matrine, has the potential to manipulate the population of E. onukii, A. spiniferus, and A. lucorum and will be an effective and environmentally compatible strategy for the control of tea pests.
[学术文献 ] Rapid and sensitive in-situ detection of pesticide residues in real tea soup with optical fiber SERS probes 进入全文
Journal of Food Composition and Analysis
The detection of pesticide residues in tea soup is an important issue in food safety. Surface-enhanced Raman scattering (SERS) spectroscopy has significant application prospects for rapid and highly sensitive detection of pesticide residues in tea, but it usually requires complex sample pre-treatment processes, and it is still a challenge to achieve highly sensitive detection of pesticide residues in complex liquid-phase system as tea soup. This article demonstrates a novel in-situ SERS detection of tea soup utilizing high-performance fiber SERS probes. Au-nanorod (AuNR) cluster-patterned fiber SERS probes are successfully prepared with a laboratory-developed laser-induced evaporation self-assembly method (LIESAM), and then the in-situ SERS detection is performed by simply immersing the fiber SERS probes into tea soup. It is demonstrated that due to the lots of SERS hotspots provided by AuNR clusters on fiber facet and the integrated collection of SERS signal in fiber SERS probes, the detection limits as low as 1.0 μg/kg for thiram and 10.0 μg/kg for paraquat in tea soup are achieved; and the relative standard deviations (RSDs) of the peak intensities are less than 10 %. The recovery rate experiments indicted the good detection accuracy of this in-situ SERS detection method in tea soup. Since no additional sample extraction is required, and the preparation of fiber SERS probes is simple and highly automated, this work provides a rapid method for highly sensitive detection of pesticide residues in tea soups, which can find important practical applications in the field of various liquid food.
[学术文献 ] Aphidius colemani Behavior Changes Depending on Volatile Organic Compounds Emitted by Plants Infected with Viruses with Different Modes of Transmission 进入全文
Insects 期刊
Natural enemies are an additional component that may interact directly with the plant–virus–vector association, affecting viral dispersion. In our study, we conducted olfactometry assays to explore how single and mixed infections with CMV or/and CABYV modify the attractiveness of A. colemani to aphid-free and aphid-infested melon plants using two melon genotypes. Subsequently, we investigated the influence of CABYV-infected plants infested by A. gossypii on the parasitism rate and emergence of A. colemani in a dual-choice assay under greenhouse conditions. Our study demonstrates that males showed no preference for either infected or non-infected plants. Female parasitoids exhibit a preference for volatiles emitted by CMV and mixed-infected melon plants over clean air but not over mock-inoculated plants, suggesting a response influenced by plant genotype. Female parasitoid responses to CABYV and its interactions with aphids revealed a preference for mock-inoculated plants over CABYV-infected plants and a parasitism rate slightly higher (7.12%) on non-infected plants. Our study revealed that (1) parasitoids may reject olfactory cues from CABYV-infected plants, potentially interfering with the plant’s “cry for help” response; (2) in the case of CMV, whether in single or mixed infections, non-infected plants are as attractive as infected ones to parasitoids. Our findings suggest that persistent viruses manipulate aphid parasitoid behavior to their advantage, promoting virus disease in melon crops.
[前沿资讯 ] The French Tea Sector Moves Toward Premiumization 进入全文
World Tea News 网站
The French tea sector is steadily growing as the popularity of tea leads to the increase of its consumption among the French. In the last couple of decades, tea has become one of the most popular hot beverages in the country, while the market has evolved from basic tea bags to high-end teas, with the latter enjoy the biggest demand these days. According to recent statistics of industry associations, in the last 25 years, the consumption of tea in France has grown by three times, while tea has never been so popular in France at present. Today, one in three French people drink it regularly. This trend is particularly observed among women, who represent 57% of consumers. According to experts of the French Viralma, among their main preferences are green teas and health and wellbeing teas, whose sales have jumped by 30% in one year. The pandemic and lockdown in France also had a significant impact on the local tea market, doubling tea consumption at home. As a result, France is now the 30th largest tea consumer in the world, importing nearly 15,000 tons of leaves each year. In value terms, the market exceeds EUR 500 million, while its growth is ongoing although the per capita consumption remains generally small, not exceeding 250 gr per year (compared to 2kg in case of UK). In general, the overall tea consumption in the country is estimated at 30,000 tonnes per year.
[学术文献 ] Design of and Experimentation with a Suction-Based Pest-Capture Machine for the Tea Pest Empoasca vitis 进入全文
Agriculture-Basel 期刊
To investigate an effective physical pest control method for tea trees, we designed and manufactured a suction-based pest-capture machine (hereafter labeled the “pest vacuum”) and conducted a test and field experiment to evaluate its effectiveness in the control of Empoasca vitis Göthe (E. vitis). Based on the proposed model, the minimum practical air velocity of the pest vacuum was 5.85 m s−1. The field experiment included two treatments and a blank control. In treatment 1, we used the pest vacuum along tea trees only once, while in treatment 2, the pest vacuum was used along trees twice, separately, in 2 consecutive periods, and with an interval of more than 30 min. The results show that a highly significant difference arose among the dropping rates of the two treatments and the blank control instantly after suction, a significant difference among the dropping rates 7 days later, and no significant difference 14 days later. The dropping rate and the effective rate of prevention of treatment 2 reached 81.87% and 80.60% instantly after suction. Moreover, the effective rate of prevention of nymphs was slightly higher than that of adults. Overall, the pest vacuum had a prominent, albeit short-term, effect on the control of E. vitis. Seven days after the suction, it is better to repeat the suction five days after the first suction. The pest vacuum provides a valid physical method for pest control, so more attention should be paid in future investigations to reducing the weight and working noise of the pest vacuum.
