Hiện trạng sử dụng thuốc bảo vệ thực vật và hiệu quả kinh tế của mô hình canh tác sầu riêng tại Cù Lao Dài, huyện Vũng Liêm, tỉnh Vĩnh Long

Nghiên cứu được thực hiện nhằm khảo sát hiện trạng sử dụng thuốc bảo vệ thực vật (BVTV) và hiệu quả tài chính trong mô hình canh tác sầu riêng tại Cù Lao Dài, huyện Vũng Liêm, tỉnh Vĩnh Long bằng phương pháp khảo sát thực địa và phỏng vấn trực tiếp 40 nông hộ trồng sầu riêng. Giống sầu riêng chủ yếu được trồng là Ri6, có giá trị kinh tế trong vụ nghịch cao hơn so với vụ chính; tuy nhiên, chi phí đầu tư trung bình trên 1 ha trong vụ nghịch cao gấp 1,66 lần so với vụ chính (đặc biệt là chi phí cho việc sử dụng thuốc BVTV). Các loại sâu bệnh xuất hiện chủ yếu là rầy nhảy, sâu đục trái, rệp sáp phấn, sâu ăn bông, cháy lá. Kết quả nghiên cứu cũng đã ghi nhận được 33 hoạt chất thuốc BVTV được nông hộ sử dụng trong quá trình canh tác sầu riêng. Trong đó, các hoạt chất có độ độc từ nhóm II (trung bình) đến nhóm IV (rất nhẹ) theo phân loại của Tổ chức Y tế Thế Giới (WHO). Đặc biệt, hoạt chất acephate bị cấm sử dụng vào năm 2019; trong khi đó, chlorpyrifos ethyl và fipronil là các hoạt chất thuộc danh mục thuốc BVTV bị cấm sử dụng kể từ ngày 12/2/2021. Liều lượng thuốc BVTV được sử dụng cao gấp 1,5-2 lần so với khuyến cáo. Hơn nữa, các phương pháp xử lý bao bì thuốc BVTV được nông dân áp dụng bao gồm đốt, chôn lấp và trữ để bán là không đảm bảo an toàn. Nhìn chung, việc sử dụng thuốc BVTV và xử lý bao bì của thuốc tiềm ẩn nhiều nguy cơ ảnh hưởng đến môi trường và...

Loại bỏ chlorpyrifos ethyl trong nước bằng than sinh học trấu

Than sinh học trấu được sản xuất ở 500oC, 700oC và 900oC được sử dụng trong nghiên cứu để hấp phụ chlorpyrifos ethyl (CE) trong nước. Ba nghiệm thức than và đối chứng (không than) được bố trí với 3 lần lặp lại. Ở mỗi lần lặp lại, 1 g than được cho vào 200 mL dung dịch CE và lắc ở tốc độ 125 vòng/phút trong 60, 120, 180 và 300 phút. Sau đó, dung dịch được lọc qua giấy lọc rồi trữ để phân tích CE còn lại trong nước bằng phương pháp sắc ký. Kết quả cho thấy than sinh học trấu có khả năng hấp phụ CE nhanh trong 60 phút đầu, sau đó giảm dần và bão hòa ở 120 phút trong điều kiện lắc. Trung bình khả năng hấp phụ CE của than trấu được sản xuất ở 500oC, 700oC và 900oC trong 300 phút lần lượt là 303,4±24,10 µg/g, 328,59±1,47 µg/g và 323,68±3,82 µg/g. Nghiên cứu khả năng hấp phụ của than này đối với một số thuốc khác là cần thiết để đưa ra khả năng ứng dụng của than sinh học trấu trong hấp phụ thuốc bảo vệ thực vật.

Low-Dose Pesticides Alter Primary Human Bone Marrow Mesenchymal Stem/Stromal Cells through ALDH2 Inhibition

(1) Background: The impact of occupational exposure to high doses of pesticides on hematologic disorders is widely studied. Yet, lifelong exposure to low doses of pesticides, and more particularly their cocktail effect, although poorly known, could also participate to the development of such hematological diseases as myelodysplastic syndrome (MDS) in elderly patients. (2) Methods: In this study, a cocktail of seven pesticides frequently present in water and food (maneb, mancozeb, iprodione, imazalil, chlorpyrifos ethyl, diazinon and dimethoate), as determined by the European Food Safety Authority, were selected. Their in vitro effects at low-doses on primary BM-MSCs from healthy volunteers were examined. (3) Results: Exposure of normal BM-MSCs to pesticides for 21 days inhibited cell proliferation and promoted DNA damage and senescence. Concomitantly, these cells presented a decrease in aldehyde dehydrogenase 2 (ALDH2: mRNA, protein and enzymatic activity) and an increase in acetaldehyde levels. Pharmacological inhibition of ALDH2 with disulfiram recapitulated the alterations induced by exposure to low doses of pesticides. Moreover, BM-MSCs capacity to support primitive hematopoiesis was significantly altered. Similar biological abnormalities were found in primary BM-MSCs derived from MDS patients. (4) Conclusions: these results suggest that ALDH2 could participate in the pathophysiology of MDS in elderly people long exposed to low doses of pesticides.

Effects of Chlorpyrifos Ethyl on Cholinesterase and Growth of Silver Barb (Barbonymus gonionotus)

Chlorpyrifos ethyl is a popular insecticide widely used in agriculture within the Vietnamese Mekong delta, including for rice farming. Here, local farmers often apply pesticides at very high rates which leads to contamination of the surrounding environment. Silver barb (Barbonymus gonionotus) is a fish species indigenous to the delta, which resides in a variety of water bodies and is also commonly cultivated in rice–fish systems. As a result, this species is at high risk of exposure to chlorpyrifos ethyl. This study aims to determine the lethal concentration (LC50) of chlorpyrifos ethyl, as well as the effects of sub-lethal concentrations on the activity of cholinesterase and growth of Silver barb. Lethal concentration testing was conducted in a static non-renewed system. Three concentrations of chlorpyrifos ethyl (1%, 10% and 20% LC50-96 h) were conducted in triplicate to assess the effects of chlorpyrifos ethyl on the brain cholinesterase (ChE) of fingerling fish for 15 days, and on their growth for 60 days. Results showed that chlorpyrifos ethyl was highly toxic to fingerling Silver barb with a LC50-96 h of 0.119 ppm. The lowest observed effect concentration (LOEC) was 1%LC50-96 h for ChE and 10%LC50-96 h for growth. No observed effect concentration (NOEC) of chlorpyrifos ethyl for growth was 1%LC50-96 h. The result from this study suggests that ChE activity is significantly inhibited at environmentally realistic concentrations in the Vietnamese Mekong delta and can be used as a biomarker of pesticide exposure. Further study in the rice fields as well as in the canals or rivers is required.

Coffee Berry Borer, Hypothenemus Hampei Ferr.: Cultural Control and In Vitro Effects of Kernel Extracts of Azadirachta indica A. Juss. and Thevetia peruviana (Pers.) Schum

The coffee berry borer, Hypothenemus hampei, is one of the most important coffee berry borer pests in the world, reaching attack rates of 10-100% in Cameroon. The objective of this study is to evaluate the efficacy of crop control and the effects of aqueous extracts of Thevetia peruviana kernel powder and aqueous extracts, and oil of Azadirachta indica kernel powder against this insect. Crop control was firstly achieved by sanitary harvesting of bark beetle-infested berries and, secondly, by the installation of a network of home-made pheromone traps. The bark beetles were breeding in the laboratory and tests were also carried out on substitute foodstuffs such as maize and groundnuts. The efficacy of pesticidal plant extracts at four concentrations each was evaluated by direct applications of these on bark beetles and berries. The results showed that the reproduction rate of the borer was 11 times higher with coffee berries than with maize and groundnuts. After the direct treatment of the bark beetles, the aqueous extracts of T. peruviana showed a significantly average efficiency on the mortality of the bark beetles ranging from 0% to 94.9% of bark beetles killed. Oil extracts of A. indica and chlorpyrifos-ethyl (Pyriforce) were more effective against bark beetles with average mortality rates ranging from 78.7 to 100%. After direct treatment of the berries, oil and aqueous extracts of A. indica and chlorpyrifos-ethyl were the most effective treatments causing more than 50% mortality of the bark beetles. Oil of A. indica and aqueous extracts of T. peruviana can therefore be used in the same way as pyriforce in the protection of coffee plants against H. hampei.

Pesticides Ecotoxicological Risk Assessment for Surface Waters in the Cotton Growing Area Around the Bala’s Hippopotamus Pond Biosphere Using PIRI Method

Pesticides residues are frequently found in the environment far from the original point of their application. Besides the desired effects of pest control, non-target organisms, soil and water are contaminated by the pesticides. This paper presents results on the impact of these xenobiotics used in cotton cultivation on River "Wolo" environment in Burkina Faso by using the Pesticide Impact Rating Index (PIRI) software package. The assessment was based on the assumption of three scenarios taking into account the organic matter content of the soil and the presence of a buffer zone. Pesticides properties and use data, and data on the physical environment, were also used. Considering the worst case (scenario 2), diuron, haloxyfop-R-methyl, glyphosate and nicosulfuron were the most mobile. Diuron was classified as the most toxic pesticide to Scenedesmus quadricauda. Toxicity to Daphnia magna was extremely high with chlorpyrifos ethyl, very high with betacyfluthrin, deltamethrin, lamda-cyalothrin and high with flubendiamide. For Oncorhynchus mykiss, it was beta-cyfluthrin, deltamethrin and lamdacyhalothrin that caused a very high risk and chlorpyrifos ethyl and indoxacarb a high risk. For all pesticides, the risks are reduced overall depending on the width of the buffer zone and the organic matter content of the soil. The use of a pesticide in a given location must take into account its ecotoxicological impact on the surrounding ecosystem. Tools such as PIRI, could be used for the selection of pesticides to be used. Also, environmental parameters such as buffer zone and organic matter content should be used by farmers to limit the mobility of pesticides to water.

Trocknungsfaktoren bei Kräutern und Einfluss der Probennahme und Probenvorbereitung auf den Gehalt an Pflanzenschutzmittel-Rückständen

In dieser Arbeit wurden anhand von Daten aus den Jahren 1991-2018 Trocknungsfaktoren für sieben in Südtirol angebaute Kräuterarten bestimmt und mit Werten aus der Literatur verglichen. Anhand von diesen Daten können Referenzwerte für die Berechnung der zulässigen Rückstandsgehalte für Kräuter im getrockneten Zustand bereitgestellt werden. Um den Einfluss der Probennahme und die Reproduzierbarkeit von Rückstandsanalysen bei einer getrockneten Kräutermischung zu untersuchen, wurden eine Reihe von Rückstandsanalysen an kommerziellen und extra gemahlenen Proben einer Mischung mit neun Kräuter-Komponenten durchgeführt. Es konnte eine hohe Reproduzierbarkeit der Rückstandanalysen bei einer Kräutermischung mit einer Kontamination mit dem Wirkstoff Chlorpyrifos-ethyl gezeigt werden. Die Probennahme hat keinen nennenswerten Einfluss auf die Rückstandsanalysen und stellt laut den vorliegenden Ergebnissen keine Ursache für erhöhte oder unplausible Rückstandswerte in Kräutern dar.

The impact of pesticides used at the agricultural land of the Puck commune on the environment of the Puck Bay

Background The Puck commune is one of the largest agricultural regions in the Pomeranian Voivodship that due to the pollution of the coastal zone negatively affects the functioning of the Puck Bay, including health of its inhabitants, and causes decrease in tourism as well as in overall economic value of the region. The objective of the undertaken study was to assess the extent of risk to the environment posed by the pesticides used in agricultural production in the coastal area of the Puck commune. Methods The study focused on organochlorine insecticides (DDT and its metabolites: α, β, ϒ, δ-HCH, aldrin, dieldrin, endrin, isodrine), glyphosate and its metabolite AMPA, and 309 active substances used as pesticides. Analyses were carried out using GC-MS, GC-MS/MS and LC-MS/MS techniques. The undertaken novel approach included “tracking” of a large number of substances in multiple environmental matrices (surface water, groundwater, seawater, soil, sediment and fish), along with examination of their transport routes from the pesticides application locality to the Puck Bay. Results Glyphosate and its metabolite AMPA, anthraquinone, boscalid, chlorpyrifos-ethyl, dimethachlor, diflufenican, difenoconazole, epoxiconazole, fluopicolide and metazachlor were found in soil samples and surface water samples collected from drainage ditches surrounding the studied agricultural plots. In the samples of seawater and fish taken from the Puck Bay no studied pesticides were found.