Efficacies of low- to high-volume (960-10 700 litre ha− 1) citrus sprayers for applying petroleum spray oil to control chinese wax scale

Petroleum spray oil (2, 4 and 6% in water) was applied to Valencia orange, Citrus sinensis (L.) Osbeck, for the control of Chinese wax scale, Ceroplastes sinensis del Guercio, using a low-volume ( <2000 litre ha^?1)air-blast (LV AB) sprayer, a low- to high-volume (L-HV) (up to 7000 litre ha^?1) sprayer with four fan-assisted rotary atomiser (FARA) spray heads mounted on a vertical tower, and a high-volume (>7000 litre ha^?1) oscillating boom (HV OB) sprayer. The most effective sprayer was the L-HV FARA sprayer. The most cost-effective treatment was a 20 ml litre^?1 (60 litre oil ha^?1) spray applied at 3000 litre ha^?1 by the L-HV FARA sprayer. It gave mortality equivalent to a standard 20 ml litre^?1, 10 700 litre ha^?1 spray (214 litre oil ha^?1) applied by the HV OB sprayer but with 72% less spray and significantly less oil deposited per cm² of leaf area. Equivalent or significantly (P = 0·05) higher mortality than that given by the 10 700 litre ha^?1 HV OB spray was given by the 40 ml litre^?1, 3000 (120 litre oil ha^?1) and 60 ml litre^?1, 2180 and 3000 litre ha^?1 (130·8 and 180 litre oil ha^?1) L-HV FARA sprays, but the 60 ml litre^?1 sprays deposited more oil per cm² than the 20 ml litre^?1 HV OB spray and were considered to be potentially phytotoxic. The least effective sprayer was the LV AB sprayer, which applied a 60 ml litre^?1 spray (57·6 litre oil ha^?1) at 960 litre ha^?1. Linear relationships were established for Chinese wax scale mortality, transformed using an angular transformation (arcsin proportion), versus log₁₀ spray volume for the 20, 40 and 60 ml litre^?1 sprays applied by L-HV FARA at 1260,2180 and 3000 litre ha^?1, mortality versus log₁₀ μg oil cm^?2 and log₁₀ μg oil versus log₁₀ volume of oil sprayed.     

Residues of the algicide endothal in water,soil and rice,after paddy field applications

In order to obtain residue data from the application of the algicide endothal in Italian rice paddy fields, two experiments were carried out using a 50 g kg^?1 granular formulation in a small pond and the same granular and two liquid formulations in actual paddy fields of the Italian rice growing area. Endothal decay in the pond water was very rapid, reaching residue levels of 0·01-1·02 mg litre^?1 in two days and 0·004-0·01 mg litre^?1 at the third day. The muddy soil of the pond was free from measurable endothal residues( <0·02 mg kg^?1). In the paddy-field waters, the endothal decay was slower, with an average half-life time of 3·3 days, independently of the type of formulation. The actual residues in water after 6 days ranged from 0·3 to 1·3 mg litre^?1 according to the initial amount of product applied, and, consequently, to the initial concentration in water. Rice samples collected at the normal harvest time from the two paddy fields, treated with three different formulations, showed no endothal residue at the minimum detectable level of 0·01 mg kg^?1.     

Degradation kinetics and safety evaluation of buprofezin residues in grape (Vitis vinifera L.) and three different soils of India

BACKGROUND: This work was undertaken to determine the preharvest interval (PHI) of buprofezin to minimize its residues in grapes and thereby ensure consumer safety and avoid possible non‐compliance in terms of residue violations in export markets. Furthermore, the residue dynamics in three grapevine soils of India was explored to assess its environmental safety. RESULTS: Residues dissipated following non‐linear two‐compartment first + first‐order kinetics. In grapes, the PHI was 31 days at both treatments (312.5 and 625 g a.i. ha^?1), with the residues below the maximum permissible intake even 1 h after foliar spraying. Random sampling of 5 kg comprising small bunchlets (8–10 berries) collected from a 1 ha area gave satisfactory homogeneity and representation of the population. A survey on the samples harvested after the PHI from supervised vineyards that received treatment at the recommended dose showed residues below the maximum residue limit (MRL) of 0.02 mg kg^?1 applicable for the European Union. In soil, the degradation rate was fastest in clay soil, followed by sandy loam and silty clay, with a half‐life within 16 days in all the soils. CONCLUSION: The recommendation of the PHI proved to be effective in minimizing buprofezin residues in grapes. Thus, this work is of high practical significance to the domestic and export grape industry of India to ensure safety compliance in respect of buprofezin residues, keeping in view the requirements of international trade. Copyright © 2008 Society of Chemical Industry     

Behaviour of trifloxystrobin and tebuconazole on grapes under semi‐arid tropical climatic conditions

BACKGROUND: A mixture of trifloxystrobin and tebuconazole is excellent in controlling both powdery and downy mildew of grapes. The objective of the present work was to study the behaviour of trifloxystrobin and tebuconazole on grape berries and soil following treatment with Nativo 75 WG, a formulation containing both fungicides (trifloxystrobin 250 + tebuconazole 500 g kg^?1). This study was carried out for planned registration of this mixture for use on grapes in India. RESULTS: Initial residue deposits of trifloxystrobin and tebuconazole on grapes were below their maximum residue limit (MRL) of 0.5 and 2 mg kg^?1, respectively, when Nativo 75 WG was applied at the recommended dose of 175 g product ha^?1. The residues dissipated gradually to 0.02 and 0.05 mg kg^?1 by 30 days, and were below the quantifiable limit of 0.01 mg kg^?1 at the time of harvest (60 days after the last treatment). Trifloxystrobin and tebuconazole dissipated at a pre‐harvest interval (PHI) of 36 and 34 days, respectively, from the recommended treatment dose. The acid metabolite of trifloxystrobin, CGA 321 113, was not detected in grape berries at any point in time. Soil at harvest was free of any pesticide residues. CONCLUSION: Residue levels of both trifloxystrobin and tebuconazole were below MRLs when grapes were harvested 30 days after the last of four applications of 175 g product ha^?1 (trifloxystrobin 44 g AI ha^?1, tebuconazole 88 g AI ha^?1) under the semi‐arid tropical climatic conditions of India. Copyright © 2010 Society of Chemical Industry     

A field unit for determining dimethoate in fruit and vegetable dips

The concentration of dimethoate in post-harvest dips needs to be maintained at 400 or 500 mg litre^?1 to ensure that fruit fly are killed and also to keep residue levels below the MRL. A field unit which contains a colorimeter, a heating block and cooling positions has been evaluated. The diluted dip sample produces a colour with 4-(p-nitrobenzyl)pyridine after heating and the addition of tetraethylenepentamine. Precision of the unit was acceptable for a field test (repeatability of ± 10.1%) and there was reasonable agreement between determinations made on the unit and by an HPLC method for a range of dimethoate concentrations from 300 to 700 mg litre^?1. The unit can be used at the dip site and the analysis is completed in 30 minutes.     

戊唑醇在葡萄和土壤中的残留和消解动态

建立了葡萄中戊唑醇残留的气相色谱测定方法,并研究了其在葡萄和土壤中的消解动态。土壤用乙腈提取,无需净化,葡萄样品用甲醇提取,二氯甲烷液液分配净化后用气相色谱-氮磷检测器(GC-NPD)测定。结果表明:在 0.01、0.1、1 mg/kg 3个添加水平下,戊唑醇的平均回收率为85.0%~98.8%,相对标准偏差(RSD)为2.9%~10.4%;最小检出量为1×10-11g,最低检测浓度为0.01 mg/kg。采用250 g/L戊唑醇水乳剂按有效成分187.5 mg/L剂量(推荐剂量的1.5倍)施药,戊唑醇在葡萄中的半衰期为9.8~12.2 d,在土壤中的半衰期为8.2~17.3 d,药后28、35 d葡萄中的最终残留量≤0.81 mg/kg,低于国际食品法典委员会(CAC)和中国规定的最大残留限量2.0 mg/kg。建议在葡萄上使用250 g/L戊唑醇水乳剂时,施药剂量最高为有效成分187.5 mg/L,施药2~3次,采收间隔期为28 d。     

Fenvalerate residues in milk following topical treatments to dairy cows

Two mature Holstein cows were treated with 0.1g of fenvalerate each, in six consecutive topical treatments at intervals of 3 or 4 days. Neither of the diastereoisomers of fenvalerate was detected in the milk 6h after the application. After 3 days, the mean fenvalerate residue was 0.46μg litre⁻¹; by day 4, this residue had declined below the detection limit of 0.1μg litre⁻¹ for each of the diastereoisomers. Two Holstein cows were also treated with 0.5g of fenvalerate per cow in three consecutive topical treatments at intervals of 14 days. Residues in whole milk were at a maximum 6h after treatment and declined to less than 0.2μg litre⁻¹ over 21 days. Only 0.03 to 0.06% of the applied fenvalerate appeared in the milk as the intact insecticide.     

Determination of residual 2,4,5-T in vegetables by high performance liquid chromatography with ultraviolet and fluorometric detection after derivatization with 2-(2,3-naphthalimino)ethyl trifluoromethanesulfonate (NE-OTf)

2,4,5-T was extracted with acetone at below pH 1·0 and the extract was concentrated. After adding 100 g litre^-1 sodium chloride solution to the residual solution, 2,4,5-T was extracted with ethyl acetate+hexane (20+80 by volume). The extract was evaporated to dryness and the residue was dissolved in acetonitrile. 18-crown-6, potassium fluoride and NE-OTf were added to the acetonitrile solution and then allowed to react at 50°C for 20 min. The product was injected to a HPLC with ultraviolet detection operated at 259 nm and fluorometric detection at 394 nm emission and 259 nm excitation. The determination limits of the 2,4,5-T derivative in the sample were 20 μg litre^-1 with UV detection and 10 μg litre^-1 with fluorometric detection. © 1997 SCI.     

Biological control of botrytis bunch rot in organic wine grapes with the yeast antagonist Candida sake CPA‐1

The aim of this research was to confirm the efficacy of the yeast antagonist Candida sake CPA‐1 in suppressing botrytis bunch rot development, in an organic vineyard under Mediterranean conditions for two seasons, and compare its performance with that of two biologically based products currently registered for botrytis bunch rot control in New Zealand. In 2009, treatments applied were: commercial formulations of Ulocladium oudemansii (BOTRY‐Zen^®) and chitosan (ARMOUR‐Zen^®), C. sake CPA‐1 combined with the fatty acid‐based additive Fungicover^® and combinations of these products. All treatments were applied six times between early flowering and harvest and compared with an unsprayed control. In 2010, the treatments focused on C. sake and Fungicover and the number of applications was reduced from six to four. The population dynamics of U. oudemansii and C. sake were measured and wine quality tests were carried out in both seasons. Disease control achieved by C. sake treatments in 2009 were comparable to those achieved by BOTRY‐Zen and ARMOUR‐Zen. Applications of C. sake plus Fungicover between flowering and harvest significantly (P < 0·05) reduced botrytis bunch rot incidence and severity by 64% and 90%, respectively, compared with the untreated control in 2009, and by 67% and 89%, respectively, in 2010. Treatments did not adversely affect wine quality parameters after treated grapes were processed. Candida sake consistently provided effective control of botrytis bunch rot in grapes under different meteorological and disease pressure conditions, thereby improving its potential for future commercial applications.     

Dissipation of cyproconazole and quinalphos on/in grapes

The persistence of cyproconazole and quinalphos on/in grapes was investigated when both compounds were applied to vines at the locally recommended application frequencies and rates and at double these rates, using commercially available formulations. Residues of cyproconazole applied at recommended and double the recommended rates of application in/on grapes immediately after the last application were 0-049 (±0.034) and 0.077 (±0.008) mg kg^?1, respectively, reduced to 0.011 (±0.003) and 0.018 (±0.010) mg kg^?1 respectively seven days after the last application. The corresponding residue levels of quinalphos immediately following the last application were 1.42 (±0.10) and 3.36 (±0.07) mg kg^?1, reduced to 0.043 (±0.002) and 0.072 (±0.028) mg kg^?1 respectively 21 days after the last application. Cyproconazole, being systemic, is rapidly absorbed by the grape tissues and its residues dissipate with a half-life of three to four days, while quinalphos, being non-systemic, dissipates faster with a half-life of two or three days. The residues of both pesticides were analysed by a GLC-NPD system.     

Effect of Hydrogen Cyanide and Carbonyl Sulphide on the Germination and Plumule Vigour of Wheat

Several factors which may influence the germination of wheat fumigated with hydrogen cyanide or carbonyl sulphide were investigated. Dosages of hydrogen cyanide ranged from 10 mg litre⁻¹ for 24-h exposure up to 150 mg litre⁻¹ for 96-h exposure. Dosages of carbonyl sulphide ranged from 25 mg litre⁻¹ for 24-h exposure up to 500 mg litre⁻¹ for 72-h exposure. The experiments were conducted on wheat of 11·4, 13·8 and 15·7% moisture content. The higher levels of these fumigants exceed those needed for control of insects in wheat. Germination was not diminished and may have been slightly enhanced with hydrogen cyanide, but was diminished by high levels of carbonyl sulphide in the drier wheat. The plumule length was reduced following all dosages of hydrogen cyanide, but only after high dosages of carbonyl sulphide, especially on the driest wheat. It is concluded that hydrogen cyanide and carbonyl sulphide could be used to control insects in wheat without affecting seed viability, provided that concentrations are carefully controlled.     

Effect of ABT on the activity and rate of degradation of isoproturon in susceptible and resistant biotypes of Phalaris minor and in wheat

The effect of the monooxygenase inhibitor, 1-aminobenzotriazole (ABT) on isoproturon phytotoxicity and metabolism was studied in resistant (R) and susceptible (S) biotypes of Phalaris minor and in wheat (Triticum aestivum). Addition of ABT (2·5, 5 and 10 mg litre^-1) to isoproturon (0·25, 0·5, 1, 2 and 4 mg litre^-1) in the nutrient solution significantly enhanced the phytotoxicity of isoproturon against the R biotype. Isoproturon at 0·25 mg litre^-1 reduced the dry weight (DW) of the S biotype by 77%, whereas the R biotype required 4·0 mg litre^-1 for similar reduction. Addition of 10 mg litre^-1 of ABT to the 0·25 mg litre^-1 isoproturon caused 71 and 82% reduction in DW of R and S biotypes, respectively. Wheat was more sensitive to the mixture of isoproturon and ABT than the R biotype of P. minor. Reduced concentrations of ABT in the mixture from 10 to 2·5 mg litre^-1 increased the DW of the R biotype more than that of the S biotype. The R biotype metabolised [¹⁴C]isoproturon at a faster rate than the S biotype. ABT (5 mg litre^-1) inhibited the degradation of [¹⁴C]isoproturon in both biotypes of P. minor and in wheat. In the presence of ABT, about half of the applied [¹⁴C]isoproturon remained as parent herbicide in all the three species after two days. The metabolites were similar in the R and S biotypes and wheat as determined by co-chromatography with reference standards and mass spectroscopy (MS). ABT inhibited the appearance of the hydroxy and monomethyl metabolites and their conjugates in all the test plants. These results suggest that the activity of the enzymes responsible for the degradation of isoproturon is greater in the R than in the S biotype of P. minor, resulting in its rapid detoxification. Incorporation of the monooxygenase inhibitor ABT into the nutrient solution greatly inhibited the degradation of [¹⁴C]isoproturon in the R biotype and increased its phytotoxicity. Both hydroxylation and N-dealkylation reactions were found to be sensitive to ABT; inhibition of hydroxylation was greater than that of demethylation. Since ABT could not completely suppress isoproturon degradation, it is possible that more than one monooxygenase is involved. © 1998 SCI     

Organophosphorus insecticide residues in virgin Greek olive oil, 1988–1990

Organophosphorus insecticide residues have been monitored for two years in virgin olive oil after dimethoate and fenthion treatments to control the olive fruit fly. No dimethoate residues were detected in any of the samples. For the first and second years, 50% and 21%, respectively, of the samples contained no detectable fenthion residues, while 4% and 6%, respectively had residue concentrations exceeding the Codex Alimentarious Maximum Residue Limit (1 mg kg^?1). The mean concentration was 0·236 mg kg^?1 oil and the estimated daily intake of fenthion 0·0002 mg kg^?1 body weight (Acceptable Daily Intake 0·001 mg kg^?1 body weight). The parent compound was the most important residue in fresh samples, while aged samples contained a higher amount of the metabolite fenthion sulfoxide. The contribution of the oxygen analogues (P= 0 metabolites) of fenthion to the total residue concentration was<5% in most cases.     

Comparative SAR Evaluations of Annonaceous Acetogenins for Pesticidal Activity

The activities of 44 Annonaceous acetogenins, which were originally isolated by monitoring plant fractionations with the brine shrimp lethality test (BST), were evaluated in the yellow fever mosquito larvae microtiter plate (YFM) assay. The results clearly demonstrate that most acetogenins have pesticidal properties. The structure–activity relationships indicate that the compounds bearing adjacent bis-THF (tetrahydrofuran) rings with three hydroxyl groups are the most potent. Bullatacin ( 1 ) and trilobin ( 7 ) gave the best activities against YFM with LC₅₀ values of 0·10 and 0·67 mg litre^-1, respectively. Compounds showing LC₅₀ values below 1·0 mg litre^-1 in this assay are usually considered significant as new lead candidates for pesticidal development. In the BST, the corresponding LC₅₀ values were 1·6×10^-3 ( 1 ) and 9·7×10^-3 ( 7 ) mg litre^-1. This is the first report of pesticidal structure–activity relationships for a series of Annonaceous acetogenins which are known to act, at least in part, as potent inhibitors of mitochondrial NADH: ubiquinone oxidoreductase. © of SCI.     

上海地产葡萄和草莓中植物生长调节剂残留及膳食摄入风险评估

为进一步提高上海市地产葡萄和草莓的安全生产水平,降低消费者的膳食摄入风险,对2018–2019年间上海当地所产152份葡萄和91份草莓样品中的20种植物生长调节剂(PGRs)残留进行了实地调研及检测分析,并就其对不同人群的长期和短期膳食摄入风险进行了初步评估.调研发现:上海市地产葡萄普遍在开花前后使用赤霉酸和氯吡脲,而...     

Pesticide residue analysis and its relationship to hazard characterisation (ADI/ARfD) and intake estimations (NEDI/NESTI)

Over 800 pesticides are currently approved for use in one or more EU countries. The maximum residue levels (MRL) for agricultural pesticides are derived from field trials conducted under good agricultural practice (GAP). The MRL is a legally enforceable limit related to GAP. The results from field trials would only be used to establish MRLs if the estimated intake of residues did not exceed the acceptable daily intake (ADI) or acute reference dose (ARfD). However, the MRL is not linked to the ADI or ARfD, and could result in intakes considerably below the ADI/ARfD. This disconnection between hazard characterisation (ADI/ARfD) and potential exposure assessment (MRL) means that risk characterisation of pesticide residues is less transparent than for other chemicals present in human food. Residue levels at or below the MRL would not give intakes that exceed the ADI/ARfD but, despite this, there is public concern over such residues. Residue levels above the MRL have to be analysed on a case-by-case basis to determine if the intake could exceed the health-based limits. Other causes of public concern, such as the presence of multiple residues, are currently under investigation.     

Residues of cypermethrin,fenvalerate and deltamethrin on cauliflower

Following the application of Cypermethrin, fenvalerate and deltamethrin to a cauliflower crop at rates of 50, 50 and 12 g a.i. ha^-1, the maximum initial deposits of these insecticides on heads and leaves were 1.10 and 0.75, 1.14 and 0.60, and 0.32 and 0.12 mg kg^-1, respectively. These residue values for fenvalerate were less than the maximum residue limit (MRL) of 2 mg kg^-1 for this crop. While the maximum initial deposits of Cypermethrin and deltamethrin on cauliflower leaves were less than their respective MRL values of 1 and 0.2 mg kg^-1 for brassica leafy vegetables, it took one day for their residues on cauliflower heads to decline below this level.     

Effects of some nonionic polyoxyethylene surfactants on uptake of ethirimol and diclobutrazol from suspension formulations applied to wheat leaves

The influence of a number of commercial nonionic polyoxyethylene surfactants on the foliar penetration and movement of two systemic fungicides, ethirimol and diclobutrazol, was studied in outdoor-grown wheat plants at different growth stages and post-treatment temperatures in two consecutive growing seasons. Both fungicides were applied as ca 0·2 μl droplets of aqueous suspension formulations containing 0·5 g litre^?1 of ¹⁴C-labelled active ingredient; surfactants were added to these suspensions at concentrations ranging from 0·2-10 g litre^?1. To achieve optimum uptake of each fungicide the use of surfactants with different physicochemical properties was required. For diclobutrazol, a lipophilic compound, uptake of radiolabel was best with surfactants of low mean molar ethylene oxide (E) content (5-6) but it was necessary to use concentrations of ca 5 g litre^?1 to attain this. The surfactant threshold concentration for uptake enhancement of radiolabel from ethirimol formulations (< 2 g litre^?1) was much lower than that for diclobutrazol but surfactants with E contents > 10 induced the greatest amount of uptake. For both fungicides, surfactants with an aliphatic alcohol hydrophobe were generally more efficient in promoting their uptake than those with a nonylphenol moiety. The sorbitan-based surfactant ‘Tween 20’ proved to be an effective adjuvant only for the ethirimol formulation; the uptake enhancing properties of the block copolymer ‘Synperonic PE/F68’ were weak. Uptake performance could not be related to the spreading properties of the respective formulations on the wheat leaf surface or to differences in solubilisation of the two fungicides by the surfactants. Although surfactants could substantially increase the amount of acropetal transport of radiolabel from both fungicides, none of those tested specifically promoted it; a constant proportion of the radioactive dose absorbed by a treated leaf was usually exported away from the site of application. The results are discussed in the light of current theories about the mode of action of surfactants as spray adjuvants.     

Further studies of the deposition and persistence of binapacryl,bupirimate and diflubenzuron on apple foliage and fruit

In an extension of previous work, deposits and residues of binapacryl, bupirimate and diflubenzuron on mature foliage and the peel of developing fruit of Worcester and Cox apple trees were monitored throughout the 1980 season following applications by mistblower sprayer. The three compounds were applied as commercial formulations in trials to compare integrated pest management with routine farm spray programmes. In contrast to previous results, all three compounds persisted on foliage until leaf-fall and were detected on the peel of harvested fruit. The mean residue of diflubenzuron on harvested Worcester fruit was 0.05 mg kg^?1 fresh weight and on harvested Cox fruit was 0.02 mg kg^?1 fresh weight. Binapacryl and bupirimate were present on harvested fruit of both cultivars. The unexpectedly long persistence of these chemicals in 1980 remains unexplained, but may be due to climatic factors.     

Enzyme immunoassay for atrazine analysis in water and soil

Enzyme immunoassay (EIA) has been tested for the detection of atrazine in soil and water. EIA kits and atrazine-fortified samples were received from the International Atomic Energy Agency. Atrazine concentrations of about 0·01 μg litre^-1 could be detected and the central detection point was found at about 0·15 μg litre^-1 which is a reasonably sensitive region for atrazine. A validation study with spiked local water samples yielded acceptable results. No treatment was required for water samples. Extraction of atrazine from soil was done by simple shaking with methanol without any clean-up steps. Detection limits of 1×10^-2 μg litre^-1 for water and 5×10^-3 μg kg^-1 for soil were achieved. © 1998 SCI.