Уточнить поиск
Результаты 1-10 из 28
Comparison of different stomatal conductance algorithms for ozone flux modelling
2007
Büker, P. | Emberson, L.D. | Ashmore, M.R. | Cambridge, H.M. | Jacobs, C.M.J. | Massman, W.J. | Müller, J. | Nikolov, N. | Novak, K. | Oksanen, E.
A multiplicative and a semi-mechanistic, BWB-type [Ball, J.T., Woodrow, I.E., Berry, J.A., 1987. A model predicting stomatal conductance and its contribution to the control of photosynthesis under different environmental conditions. In: Biggens, J. (Ed.), Progress in Photosynthesis Research, vol. IV. Martinus Nijhoff, Dordrecht, pp. 221-224.] algorithm for calculating stomatal conductance (gs) at the leaf level have been parameterised for two crop and two tree species to test their use in regional scale ozone deposition modelling. The algorithms were tested against measured, site-specific data for durum wheat, grapevine, beech and birch of different European provenances. A direct comparison of both algorithms showed a similar performance in predicting hourly means and daily time-courses of gs, whereas the multiplicative algorithm outperformed the BWB-type algorithm in modelling seasonal time-courses due to the inclusion of a phenology function. The re-parameterisation of the algorithms for local conditions in order to validate ozone deposition modelling on a European scale reveals the higher input requirements of the BWB-type algorithm as compared to the multiplicative algorithm because of the need of the former to model net photosynthesis (An).
Показать больше [+] Меньше [-]Gating in grapevine: Relationship between application of the fungicide fludioxonil and circadian rhythm on photosynthesis
2009
Petit, Anne-Noëlle | Fontaine, Florence | Clement, Christophe | Vaillant-Gaveau, Nathalie
The aim of this study was to determine the impact of the fludioxonil (fdx) fungicide on the diurnal fluctuation in grapevine photosynthesis. Therefore, fdx treatment was performed at the end of flowering, at 8 am, 12 am or 7 pm. The study was performed in experimental field and several photosynthesis parameters were followed one day after treatment. Morning fdx treatment induced (i) a significant and simultaneous drop of both photosynthesis (Pn) and stomatal conductance between 8 am and 4 pm and (ii) an increase of intercellular CO2 concentration when compared to control plants. On the contrary, evening fdx treatment did not affect Pn whereas midday treatment caused Pn increase after 4 pm. These data suggest that (i) morning fdx treatment results in a non-stomatal limitation of Pn, (ii) midday treatment is more suitable to treat grapevine with fdx and (iii) a phenomenon of gating was noticed. The period of fdx spraying was an important parameter in stress response: the midday fdx treatment is more suitable to treat grapevine with fdx.
Показать больше [+] Меньше [-]Multi-omics analyses on the response mechanisms of ‘Shine Muscat’ grapevine to low degree of excess copper stress (Low-ECS)
2021
Chen, Mengxia | Fang, Xiang | Wang, Zicheng | Shangguan, Lingfei | Liu, Tianhua | Chen, Chun | Liu, Zhongjie | Ge, Mengqing | Zhang, Chuan | Zheng, Ting | Fang, Jinggui
Copper stress is one of the most severe heavy metal stresses in plants. Grapevine has a relatively higher copper tolerance than other fruit crops. However, there are no reports regarding the tolerance mechanisms of the ‘Shine Muscat’ (‘SM’) grape to a low degree of excess copper stress (Low-ECS). Based on the physiological indicators and multi-omics (transcriptome, proteome, metabolome, and microRNAome) data, 8 h (h) after copper treatment was the most severe stress time point. Nonetheless, copper stress was alleviated 64 h after treatment. Cu ion transportation, photosynthesis pathway, antioxidant system, hormone metabolism, and autophagy were the primary response systems in ‘SM’ grapevine under Low-ECS. Numerous genes and proteins, such as HMA5, ABC transporters, PMM, GME, DHAR, MDHAR, ARGs, and ARPs, played essential roles in the ‘SM’ grapevine's response to Low-ECS. This work was carried out to gain insights into the multi-omics responses of ‘SM’ grapevine to Low-ECS. This study provides genetic and agronomic information that will guide better vinery management and breeding copper-resistant grape cultivars.
Показать больше [+] Меньше [-]Cumulative risk assessment of dietary exposure to triazole fungicides from 13 daily-consumed foods in China
2021
Cui, Kai | Wu, Xiaohu | Zhang, Ying | Cao, Junli | Wei, Dongmei | Xu, Jun | Dong, Fengshou | Liu, Xingang | Zheng, Yongquan
The agroeconomic benefits of the routine use of triazole fungicides on crops have been evident for more than 40 years. However, increasing evidence shows that residues of triazoles are ubiquitous in various foods and thus could pose a potential health risk to humans. We analyzed 3406 samples of 13 food commodities that were collected from markets in 9 regions across China, and assessed the health risk of both chronic and acute exposure to the triazoles for Chinese children (1–6 years old) and the general population. Among all samples, 55.52% had triazoles in concentrations of 0.10–803.30 μg/kg, and 29.77% of samples contained a combination of 2–7 triazoles. Tebuconazole and difenoconazole were the most commonly found triazoles in the foods, being detected in 33.44% and 30.45% of samples, respectively. Chronic and acute cumulative risk assessment for total triazoles based on a relative potency factor method revealed that exposure to triazoles from these particular commodities was below the levels that might pose a health risk (chronic hazard index range, 5.90×10⁻⁷ to 1.83×10⁻³; acute hazard index range, 7.77×10⁻⁵ to 0.39, below 1). Notably, dietary exposure risk for children was greater than that for the general population—particularly for the acute intake of mandarin, grape, and cucumber (acute hazard index values of 0.35–0.39). Despite the low health risk, the potential hazards of exposure to triazoles should raise public concern owing to their ubiquitous presence in common foods and potential cumulative effects.
Показать больше [+] Меньше [-]Relation between organophosphate pesticide metabolite concentrations with pesticide exposures, socio-economic factors and lifestyles: A cross-sectional study among school boys in the rural Western Cape, South Africa
2021
Molomo, Regina Ntsubise | Basera, Wisdom | Chetty-Mhlanga, Shala | Fuhrimann, Samuel | Mugari, Mufaro | Wiesner, Lubbe | Röösli, Martin | Dalvie, Mohamed Aqiel
Evidence on the relationship between lifestyle, socio-economic factors and pesticide exposure and urinary concentrations of organophosphate (OP) pesticide metabolites among children is generally incomplete. This study investigated the relationship between socio-economic factors and reported pesticide exposures and the sum of three urinary concentrations of dialkyl phosphate metabolites (DAP) among boys living in the rural areas of the Western Cape, South Africa. Data was collected during a cross-sectional study of 183 boys from three agricultural intense areas. Measurements included a questionnaire on socio-economic and pesticide exposures and urinary DAP concentrations. Most boys (70%) lived on farms with a median age of 12 years (range: 5.0–19.5 years). Children aged >14 years had lower DAP urine concentrations (median = 39.9 ng/ml; β = −68.1 ng/ml; 95% CI: −136.8, 0.6) than children aged 9 years and younger (median = 107.0 ng/ml). DAP concentrations also varied significantly with area, with concentrations in the grape farming area, Hex River Valley (median = 61.8 ng/ml; β = −52.1; 95% CI: −97.9, −6.3 ng/ml) and the wheat farming area, Piketberg (median = 72.4 ng/ml; β = −54.2; 95% CI: 98.8, −9.7 ng/ml) lower than those in the pome farming area, Grabouw (median = 79.9 ng/ml). Other weaker and non-significant associations with increased DAP levels were found with increased household income, member of household working with pesticides, living on a farm, drinking water from an open water source and eating crops from the vineyard and or garden. The study found younger age and living in and around apple and grape farms to be associated with increased urinary DAP concentrations. Additionally, there were other pesticide exposures and socio-economic and lifestyle factors that were weakly associated with elevated urinary DAP levels requiring further study. The study provided more evidence on factors associated to urinary DAP concentrations especially in developing country settings.
Показать больше [+] Меньше [-]Woody residues of the grape production chain as an alternative precursor of high porous activated carbon with remarkable performance for naproxen uptake from water
2022
Georgin, Jordana | Netto, Matias S. | Franco, Dison S. P. | Piccilli, Daniel G. A. | da Boit Martinello, Kátia | Silva, Luis F. O. | Foletto, Edson L. | Dotto, Guilherme L.
Activated carbon prepared from grape branches was used as a remarkable adsorbent to uptake naproxen and treat a synthetic mixture from aqueous solutions. The material presented a highly porous texture, a surface area of 938 m² g⁻¹, and certain functional groups, which were key factors to uptake naproxen from effluents. The maximum adsorption capacity predicted by the Langmuir model for naproxen was 176 mg g⁻¹. The thermodynamic study revealed that the adsorption process was endothermic and spontaneous. The linear driving force (LDF) model presented a good statistical adjustment to the experimental decay data. A suitable interaction pathway of naproxen adsorption onto activated carbon was proposed. The adsorbent material was highly efficient to treat a synthetic mixture containing several drugs and salts, reaching 95.63% removal. Last, it was found that the adsorbent can be regenerated up to 7 times using an HCl solution. Overall, the results proved that the activated carbon derived from grape branches could be an effective and sustainable adsorbent to treat wastewaters containing drugs.
Показать больше [+] Меньше [-]Suspension of pheromone microcapsules on vine leaves acting as passive dispensers against pests
2022
Desauziers, Valérie | Sicre, Elodie | Vignau-Laulhère, Jane | Bourrigaud, Sylvain | Plaisance, Hervé
Pheromones are increasingly used as alternatives to pesticides to protect vineyards against L. botrana, a key grape pest. To diffuse (7E,9Z)-7,9-dodecadien-1-ylacetate, the L. botrana pheromone, passive, or aerosol dispensers are commonly applied. This paper deals with another method based on spraying an aqueous formulation, Lobesia Pro Spray, containing the pheromone encapsulated in a resin. The objectives were to assess the ability of vine leaves to act as pheromone dispensers and to check that encapsulation protects the plant from pheromone penetration. Laboratory testing based on an emission cell combined with airborne pheromone measurements by active sampling on sorbent tubes followed by ATD-GC–MS analysis was developed to accurately characterise the release of the pheromone into the air. Release kinetics analysis performed on the vine leaves showed a high pheromone release (about 30% of the sprayed quantity) the first day of the test. The release rate then decreased rapidly to reach about 650 mg/day/ha after 4 days. Kinetic modelling showed that it would be possible to maintain an effective airborne concentration of pheromone for approximately 12 days. Release tests were also carried out on glass, PVC and blotting paper. The results obtained showed that the vine leaves behaved as a non-absorbent material, implying that the pheromone used in the Lobesia Pro Spray formulation did not penetrate the plant. These first results prove the feasibility of using vine leaves as pheromone dispensers for a sprayed formulation and the ability to optimise the treatment conditions (dose and frequency) through laboratory testing.
Показать больше [+] Меньше [-]Evaluation of pesticide residues in fruits and vegetables from the Aegean region of Turkey and assessment of risk to consumers
2021
Kazar Soydan, Didem | Turgut, Nalan | Yalçın, Melis | Turgut, Cafer | Karakuş, Perihan Binnur Kurt
Pesticides may cause a potential risk to human health when applied in excess to control pests, diseases, and weeds in crop fields. In the current study, conducted in the Aegean region of Turkey from 2012 to 2016, a total of 3044 samples of 16 different commodities of fruits and vegetables were screened to identify pesticide residues and health risk to consumers posed by such residues was assessed. Results showed that 354 samples out of the total samples had higher maximum residue limit (MRL) values, while the MRL values were lower in 473 samples. In the study, residues of 64 different pesticides detected in 3044 samples in which 11.6% samples exceeded maximum residue limit (MRL) levels as compared with that of the approved MRL level by the Turkish authorities. Out of total samples, number of samples having high MRL level were as follows: 74 for chlorpyrifos (2.43%), 145 for azoxystrobin (3.8%), 112 for triadimenol (3.8%), 103 for carbendazim (3.4%), 98 for chlorpyrifos (3.2%), 94 for pyrimethanil (3.10%), 90 for cyprodinil (2.9%), 76 for fludioxonil (2.50%), 75 for indoxacarb (2.40%), 66 for imidacloprid (2.10%), and 60 for boscalid (1.90%). Residues of one, two, three, four, and even more than five pesticides were detected, respectively, in 16.1, 5.8, 2.8, 1, and 1.7% of the total test samples. The lowest estimated daily intake (EDI) values ranged from 3.57×10⁻³ to 8.98. The lower values of hazard quotient (HQ) were obtained in dried apricot, grape, and strawberry with the value of 0.01, although the HQ value in 32 out of 62 pesticides tested was found to be close to 0.
Показать больше [+] Меньше [-]New Insights into the Role of Chemical Components on Metal Ions Sorption by Grape Stalks Waste
2015
Liu, C. | Pujol, D. | Fiol, N. | Olivella, M. À | de la Torre, F. | Poch, J. | Villaescusa, I.
In this work, metal sorption onto grape stalks waste structural compounds and extractives has been studied for determining their role in Cr(VI), Cu(II) and Ni(II) metal sorption. For this purpose, a sequential extraction of extractives and other compounds from the lignocellulosic material has been carried out. The resulting solid samples obtained in the different extraction processes were used as sorbents of Cr(VI), Cu(II) and Ni(II). Sorption results were discussed taking into account the elemental composition and polarity of the solid extracts. Results indicated that tannins and polyphenols are involved in chromium reduction and sorption. Lignin and celluloses are involved in chromium, Cu(II) and Ni(II) sorption. FTIR analysis confirmed the involvement of lignin moieties in the studied metal ions sorption by grape stalks waste. This study presents a new approach on metal sorption field as the knowledge of the role of the sorbent chemical compounds is essential to determine the key sorbent compounds in the sorption process.
Показать больше [+] Меньше [-]Insight into how fertilization strategies increase quality of grape (Kyoho) and shift microbial community
2022
Li, Xunan | Chu, Changbin | Ding, Sheng | Wei, Huawei | Wu, Shuhang | Xie, Bing
Organic and bioorganic fertilizers were increasingly used for agricultural soil. However, little is known on what kind of organic fertilizer application strategies can promote grape production well and how appropriate fertilization strategies improve soil properties and shift microbial community. This study investigated the improvement in soil physicochemical properties as well as their relations with microbial community structure and grape quality under different fertilization strategies. Our results found that (bio)organic fertilizer (CF1, CF2, and BF) especially combined application of organic and bioorganic fertilization (CBF) had smaller effects on electrical conductivity (EC) and pH, while it improved soil nutrients including N, P, K, and organic matter (OM) well, thereby promoting the grape quality comparing to the group without any fertilizer (CK) and with chemical fertilizer (NPK). Especially, the concentrations of Cr, Hg, Zn, and Cu were reduced by 13.63%, 12.50%, 12.52%, and 11.75% in CBF, respectively. Additionally, CF1, CF2, and BF, especially CBF, optimized the communities’ composition and increased the abundance of some plant probiotics such as Solirubrobacter and Lysobacter. Nevertheless, excessive application of organic fertilizer derived from livestock manure could cause the accumulation of heavy metals such as Zn and Cu in soil and leaves, which could further influence the grape quality. Additionally, the structure of microbial communities was also changed possibly because some bacterial genera showed distinct adaptability to the stress of heavy metals or the utilization capacity of N, P, K, and OM. Our results demonstrated that combined application of organic and bioorganic fertilization showed a great influence on soil physicochemical properties, whose positive changes could further optimize microbial communities and facilitate the promotion of grape quality.
Показать больше [+] Меньше [-]