吡虫啉和啶虫脒在两种叶菜上残留的原始沉积行为及其影响因素

叶菜上农药原始沉积行为受作物形态、农药种类及其剂型、施用方式等多种因素的影响,是评估农药残留的重要指标。以吡虫啉和啶虫脒为目标农药,以菠菜和生菜作为靶标作物,通过农药施用后的原始沉积行为,以及兑水量、叶面积指数和农药剂型对农药沉积的影响,初步揭示了农药原始沉积规律。结果表明：施药后0.5～8 h内其沉积量无显著差异,综合考虑,选择施药后2 h时测定其原始沉积量;两种农药在菠菜和生菜中主要沉积在叶片表面,沉积量占比均在87%以上,在根和土壤中的沉积量较少;农药施药剂量相同而兑水量不同,则原始沉积量存在显著差异,随着兑水量的增加,沉积量逐渐减少;菠菜和生菜中农药沉积量与叶面积指数呈负相关;原始沉积量与剂型也有相关性,在施药剂量相同时,吡虫啉在菠菜、生菜中原始沉积量最高均为可湿性粉剂,沉积量分别为0.66和0.77 mg/kg;啶虫脒在菠菜中原始沉积量最高为乳油和可湿性粉剂,沉积量均为0.65 mg/kg,生菜中原始沉积量最高为可湿性粉剂,沉积量为0.37 mg/kg。研究结果认为,农药剂型、兑水量和叶面积指数均会影响叶菜表面农药原始沉积量,该结果可为叶菜中农药合理安全施用和农药残留管控提供...     

不同剂型吡虫啉在烟叶和土壤中的残留及消解动态

采用高效液相色谱检测技术,于2010—2011年开展了吡虫啉可溶液剂、可湿性粉剂、微乳剂和颗粒剂4种常见剂型的不同施药剂量、不同施药次数和采收间隔期的田间试验,研究了不同剂型吡虫啉在烟叶和土壤中的残留降解规律与最终残留量。结果表明,在3个添加水平（0.01~5 mg/kg）、5次重复下,鲜烟叶、干烟叶和土壤中吡虫啉的平均回收率和相对标准偏差（RSD）分别为85.6% ~89.3%,5.0% ~5.7%;85.0% ~88.3%,3.5% ~5.0%;84.1% ~91.5%,3.4% ~8.0%;符合农药残留检测要求。吡虫啉最小检出量（LOD）为0.3 ng（S/N=3）,最低检测浓度（LOQ）分别为:鲜烟叶0.01 mg/kg,干烟叶0.03 mg/kg,土壤0.01 mg/kg。由于推荐剂量不同,不同剂型农药在烟叶上的原始沉积量有较大差别,可溶液剂、可湿性粉剂、微乳剂和颗粒剂4种剂型的吡虫啉降解速率均较快,半衰期分别为5.7~6.6、3.1~3.7、5.0~5.1和10.5~11.4 d。在不同处理的干烟叶中,吡虫啉残留量有明显差异,根据国际烟草科学合作研究中心（CORESTA）的指导性残留限量为5 mg/kg,建议大田喷雾施药的3种剂型（可溶液剂、可湿性粉剂和微乳剂）安全间隔期为14 d,移栽期穴施的颗粒剂安全间隔期为70 d。     

桃果套袋对6种典型农药沉积分布和残留的影响

建立了一种基于QuEChERS方法提取净化,超高效液相色谱/气相色谱-串联质谱检测桃叶、桃果和土壤中吡虫啉、嘧菌酯、腈苯唑、苯醚甲环唑、毒死蜱及β-氯氰菊酯6种农药残留量的分析方法。结果表明:在0.05~20 mg/kg (桃叶)、0.05~2 mg/kg (桃果) 和0.05~5 mg/kg (土壤) 添加水平下,6种农药在桃叶、桃果及土壤中的回收率为72%~111%,相对标准偏差 (RSDs) 为0.90%~18% (n = 5),均满足农药残留检测的要求。不套袋施药时,6种农药在桃叶中的原始沉积量最高,其沉积量占比为桃叶、桃果和土壤中总残留量的57%~69%;其次是土壤中,占比为25%~39%,桃果中占比仅为3%~6%;此外,2次施药后14和21 d时桃果上6种农药的最终残留量分别为 (0.07 ± 0.01)~(0.77 ± 0.13) mg/kg和 <0.05~(0.27 ± 0.05) mg/kg,分别为其对应最大残留限量(MRL)值的15%~60%和9%~34%。套袋可以显著降低桃果中6种农药的原始沉积量和最终残留量。套袋后,桃果上6种农药的原始沉积量占比均小于1%,且2次施药后14和21 d时的最终残留量均低于中国国家标准GB 2763—2019《食品安全国家标准 食品中农药最大残留限量》中对应MRL值的10%。本研究明确了果实套袋对6种农药在桃园中的沉积和残留的影响,为指导果实套袋措施在桃园中的安全使用提供了理论依据。     

茚虫威在菜用大豆上残留动态及安全使用技术

采用气相色谱法(GC/ECD)研究了菜用大豆中茚虫威残留量的检测方法,以及茚虫威在菜用大豆上的残留消解动态,并对其安全使用技术进行了示范试验。结果表明,建立的菜用大豆中茚虫威残留量定量检测方法的平均回收率为86.8% ~90.1%,相对标准偏差为3.85% ~5.24%,最小检出量0.01 ng,最低检测浓度为0.005 mg/kg,该方法简便、准确、能满足实际样品分析。茚虫威在菜用大豆上的原始沉积量因不同施药处理有所差异,施用有效成分96.43 g/hm2的原始沉积量＞施用有效成分48.21 g/hm2的原始沉积量,间隔期7 d连续施药两次的原始沉积量＞施药1次;残留消解动态符合一级动力学方程,早季的消解系数(︱k︱)=0.174 75±0.000 15,半衰期(T1/2)为4.0 d,消解99%所需要的时间(T0.99)为26.3 ~26.4 d;晚季︱k︱=0.108 35±0.004 95,T1/2为6.1 ~6.7 d,T0.99为40.6 ~45.5 d。在安全使用技术示范试验区,茚虫威按常规施药量(有效成分67.50 g/hm2)及施药方法,2006年晚季施药1次与间隔期7 d连续施药两次,在末次施药后25 d、30 d,最终残留量分别为0.065 ~0.102 mg/kg和0.032 ~0.081 mg/kg;2007年早季间隔期7 d 连续施药两次,在第2次施药后15 d,最终残留量为0.097 ~0.132 mg/kg,产品质量安全水平均符合日本规定的MRL(0.2 mg/kg)要求。     

喷雾参数对自走式喷杆喷雾机稻田喷雾农药利用率及雾滴沉积分布的影响

比较在不同喷雾压力和施药液量条件下,采用自走式喷杆喷雾机在水稻分蘖期、孕穗期、扬花期进行喷雾处理的农药利用率、沉积分布均匀性及水稻茎基部雾滴密度的差异,为建立自走式喷杆喷雾机在稻田的高效施药技术提供理论依据。以生物染料丽春红-G作为农药示踪剂,估测不同喷雾参数的农药利用率,并用变异系数、绝对份额比例值比较农药分布的均匀性。同时通过水敏纸收集水稻基部雾滴密度,分析不同喷雾参数下农药雾滴穿透水稻冠层的能力。结果表明:在水稻分蘖期,采用自走式喷杆喷雾机在喷雾压力为1.2 MPa、施药液量为375 L/hm^2条件下喷雾,每个采样点的丽春红-G的平均沉积量仅为0.11 mg,与喷雾压力为0.4 MPa、施药液量为300 L/hm^2条件下喷雾的沉积量相比减少了56.00%。在水稻孕穗期,当喷雾压力为1.2 MPa、施药液量为375 L/hm^2时进行喷雾处理,每个采样点的丽春红-G的平均沉积量达0.26 mg,显著高于其他4个处理。在水稻扬花期,不同喷雾参数间的沉积量差距减小。在合适的喷雾压力和施药液量时,自走式喷杆喷雾机在水稻分蘖期、孕穗期和扬花期进行喷雾处理,农药利用率分别达到40.57%、54.97%和55.50%。综合变异系数和绝对份额比例两个指标,采用自走式喷杆喷雾机在喷雾压力为0.8 MPa、施药液量为300 L/hm^2条件下喷雾,农药分布更均匀。喷雾压力对水稻基部雾滴密度有显著影响,在水稻生长中后期,当喷雾压力低于0.8 MPa、施药液量为225~375 L/hm^2时,水稻茎秆基部雾滴密度均小于30个/cm^2。研究结果表明,喷雾压力和施药液量对自走式喷杆喷雾机稻田喷雾的农药利用率、分布均匀性及水稻茎秆基部雾滴密度有显著影响。在水稻生长前期,不宜采用高压力大水量喷雾作业;在水稻生长中后期,为增加对水稻基部病虫害的防治效果,需提高喷雾压力。     

不同施药器械对环酰菌胺在番茄叶片上的沉积量及其对灰霉病防治效果的影响

农药的沉积量是判定农药有效利用率的重要指标之一。采用3种不同的喷雾器喷施防治灰霉病的化学药剂——10%环酰菌胺可湿性粉剂于大棚种植的番茄上,并于2 h后采集番茄叶片,通过构建气相色谱法（带UECD检测器）,分析不同的施药器械对农药沉积量及防治效果的影响。结果表明:采用3WBD-16型背负式电动喷雾器和3WJD-18静电喷雾器施药,环酰菌胺在番茄叶片上的沉积量分别为3.25和5.61 mg/kg,而采用TSP-60（S）热力烟雾器施药,环酰菌胺沉积量最高,达12.83 mg/kg;在防治番茄灰霉病方面,也以热力烟雾器的防治效果最好（对番茄叶片和果实上灰霉病的防治效果分别为86.53%和85.50%）,显著高于背负式电动喷雾器处理（叶防效73.88%,果防效74.03%）,与静电喷雾器处理的叶防效（77.45%）差异显著,而与果防效（79.85%）无显著差异。本研究结果表明,TSP-60（S）热力烟雾器和3WJD-18静电喷雾器均能提高环酰菌胺在番茄叶片上的沉积量,并可提高对大棚番茄灰霉病的防治效果。     

热烟雾法喷施苯醚甲环唑防治黄瓜白粉病的研究

采用6HYC-42A型热烟雾机喷施10％苯醚甲环唑WG防治温室黄瓜白粉病,以背负式手动喷雾器常规喷雾为对照,比较了不同施药方式的农药在黄瓜植株不同部位的雾滴沉积分布规律以及对白粉病防效的差异.同时,利用液质联用检测了热烟雾法喷施苯醚甲环唑在黄瓜果实、叶片及土壤中的残留及消解动态.试验结果表明:①热烟雾法的雾滴体积中径为15 μm,手动喷雾法的雾滴体积中径为215 μm.②热烟雾法施药,黄瓜叶片正面的雾滴沉积密度明显高于叶片反面.当热烟雾机背靠日光温室北墙、喷头向南在黄瓜行间对空喷雾时,农药雾滴在黄瓜上部、中部、下部的雾滴沉积分布都表现为距离喷口越远密度越大.热烟雾法的雾滴沉积密度明显大于手动喷雾法.③采用热烟雾法喷施苯醚甲环唑,在有效成分用量为5.0、6.7、8.3 g/667m2时,对黄瓜白粉病的防治效果分别为81.4％、94.4％、97.9％,而手动喷雾法在相同有效成分用量时防效为74.2％、78.4％和83.6％.④热烟雾法施药时苯醚甲环唑在黄瓜果实中的原始沉积量为0.008 3 mg/kg,远低于UK/EC制定的苯醚甲环唑在黄瓜中最高残留量限值0.10 mg/kg.     

施药因子对三唑磷在水稻上残留沉积的影响

采用室内模拟试验方法,研究了施药剂量、稀释倍数、施药次数、剂型、施药时期对三唑磷在水稻上原始沉积的影响,并通过套袋处理探讨了穗期施药对糙米中三唑磷最终残留量的影响。结果表明,三唑磷的原始沉积量与施药剂量呈线性正相关关系,与稀释倍数呈线性负相关关系,线性方程分别为:y=0.883 1+0.352 7x( r=0.982 2)和y=110.21-0.200 5x(r=0.986 2),施药次数与三唑磷残留量呈正相关;于穗期施药后,未套袋处理糙米中三唑磷的残留量显著高于套袋处理。明确了田间施药过程中影响三唑磷在水稻上原始沉积量的主要因子为施药剂量、施药次数和稀释倍数,探明了套袋处理能有效降低糙米和谷壳中三唑磷的残留量,可为科学合理施药以有效降低农药残留提供参考。     

喷杆喷雾机在小麦田减量喷雾作业的效果探究

通过在小麦田开展喷杆喷雾机施药防治病虫害的试验,探究该施药方式下减少药液量对农药沉积量、利用率、防治小麦病虫效果以及小麦产量的影响,以明确该药械在麦田减量喷雾作业的效果及适宜参数.研究结果表明,与常规施液量450 L/hm2相比,喷施药液量降至150 L/hm2可显著提高药液在小麦冠层的沉积量和沉积利用率,在小麦冠层上...     

基于沉积量和生物效果的甘蓝小菜蛾防治喷雾参数优化

为明确不同喷雾参数对农药在甘蓝叶片表面的沉积和药剂生物效果的影响,在自走式喷雾塔内模拟田间喷雾条件,采用正交试验和单因子试验评价了喷头、喷液表面张力、施液量、喷雾压力及喷雾高度5个因子的影响程度及各因子间的相互作用,并采用响应曲面法优化了喷雾参数。结果表明:相较于喷头和喷雾高度,喷液表面张力、施液量和喷雾压力极显著影响农药沉积和药剂生物效果,其中喷液表面张力的影响最大;基于后3个指标以响应曲面法建立的甘蓝叶片表面农药沉积和苏云金芽胞杆菌防治小菜蛾生物效果的回归模型经验证准确有效,相关系数分别为0.9731和0.7790,能够用于预测农药沉积量和药剂生物效果。综合考虑防治甘蓝小菜蛾喷雾作业过程中的实际情况及成本控制,设定和调节目标函数满足单位面积农药沉积量大于4.0μg/cm2,且苏云金芽胞杆菌防治小菜蛾死亡率大于80%,获得苏云金芽胞杆菌防治甘蓝小菜蛾喷雾参数的优选范围为:Silwet-408助剂浓度13.50~44.00 mg/L、喷雾压力0.2~0.6 MPa、施液量300~717.6 L/hm2。     

基于GC/MS测定法的不同种植条件下代森锰锌在菜豆上的残留及消解动态

采用正己烷吸收,气质联用仪测定,建立了代森锰锌在菜豆中的GC/MS测定法。方法回收率为79.0%～85.6%,相对标准偏差为4.4%～9.9%,定量限以代森锰锌表示为0.04 mg/kg。在此基础上开展了不同种植条件下代森锰锌在菜豆上的消解动态试验和最终残留量试验,设施条件下和露地条件下代森锰锌在菜豆上的半衰期分别为9.4 d和5.1 d,最终残留量为0.17～0.45 mg/kg,均低于我国限量标准3 mg/kg。可为70%硫磺·锰锌可湿性粉剂用于防治菜豆病害登记提供数据支撑。     

Effect of different formulations on tebuconazole residues in stone fruits

BACKGROUND: The correlation between pesticide residue levels and formulation of an active substance is often not considered, even if it is reasonable to expect some differences arising from behaviour during dilution and spraying, from adhesion to plant and from degradation. An experimental study to investigate the magnitude of tebuconazole residues as a function of different tebuconazole formulated products was carried out in Italy. The fungicide was applied as wettable powder (WP) and water‐dispersible granule (WG) formulations to peach, plum, apricot and nectarine orchards, on four different sites. The fruit samples gained from the field trials were quantitatively analysed by gas chromatography with a nitrogen phosphorus detector (GC/NPD) for tebuconazole residues. RESULTS: Tebuconazole residues in the fruits gained from the plot treated with the WP formulation, 14 days after application, were in the range 0.01–0.07 mg kg^?1, while corresponding residues in the plot treated with the WG formulation were in the range 0.01–0.06 mg kg^?1. CONCLUSION: No significant differences in the residue levels of tebuconazole could be observed between the trials conducted with the WP and the WG formulation. Copyright © 2009 Society of Chemical Industry     

Efficacy of aerial application ofBacillus thuringiensis to controlSpodoptera littoralis (Lepidoptera, Noctuidae) infesting soybean cultivations in Egypt

The calculated percentage of droplets deposition ofBacillus thuringiensis var.kurstaki HD-1 Dipel 2X on the foliage of soybean plants in relation to the sensitive “Ciba Geigy” papers showed to be the highest (92.4%) after ground spray application, compared to an average of 67.4, 85.8 and 89.3% following aerial application of the same preparation in spray volumes of 10, 20 and 30 l/F, respectively. Aerial application ofB. t. showed to be more effective during the first 3 days after spraying soybean cultivations and the mortality ofSpodoptera littoralis larvae varied between 36.9–67.2% in correlation to the spray volume. The volume achieving the highest and significant suppression of infestation was 20 l/F. On the other hand, the yield of soybeans obtained from plots receiving a spray volume of 30 l/F was higher compared to plots sprayed with a volume of 20 or 10 l/F, but with no significant difference when compared to those plots receiving ground spray application.     

吡虫啉和噻虫嗪对苜蓿盲蝽的防治效果及其在苜蓿中的残留

为了评价新烟碱类杀虫剂吡虫啉和噻虫嗪对苜蓿盲蝽的防治效果及安全性,采用田间喷雾法测定了20%吡虫啉可溶液剂(SL)和30%噻虫嗪悬浮剂(SC)对苜蓿盲蝽的防治效果,使用超高效液相色谱-串联质谱法(UPLC-MS/MS)测定了施药1、2、3次后(间隔7 d),药剂在苜蓿中的残留情况。结果表明,当吡虫啉和噻虫嗪在施药剂量分别为25.02 g/hm²和18.00 g/hm²时,药后3～7 d对苜蓿盲蝽的防治效果分别为80.01%～82.01%和77.54%～83.29%。吡虫啉和噻虫嗪连续施药3次后,在苜蓿中的最终残留量分别为1.90 mg/kg和0.08 mg/kg,吡虫啉已超过我国食品安全国家标准GB 2763-2021规定的果蔬中的最大残留限量(0.5 mg/kg)。因此建议每茬苜蓿生长期,可选用吡虫啉和噻虫嗪防治苜蓿盲蝽,吡虫啉和噻虫嗪喷施次数分别不宜超过2次和3次。     

Retention of iprodione on salad onion leaves in relation to the control of Botrytis spp.

Using bioassay and fluorescent tracer techniques it was demonstrated that more fungicide was retained on mature leaves of summer salad onion crops if 1 kg/ha iprodione wettable powder (w.p.) formulation plus wetting agent was sprayed at 280 1/ha than at 560 1/ha or 1120 1/ha.
The lowest spray volume (280 1/ha) with four sprays of iprodione w.p. (0.5 kg in October, November, December and January) gave effective control of Botrytis cinerea and significantly increased plant stand and yield. More fungicide was required to obtain equivalent results using a mixed programme of two thiram (4 kg/ha total) and two iprodione w.p. (2 kg a.i./ha total) sprays at the same application volume and intervals. Where the mixed programme was applied at 1 1 20 1/ha, 1 2 kg a.i. (total fungicide) was necessary to achieve equivalent disease control.
At 280 1/ha, retention and persistence of iprodione on onion foliage was greater with the oil-based than with the wettable powder formulation. In summer especially this resulted in improved Botrytis control and greater numbers of marketable onions. In winter onions, oil and w.p. formulations were equally effective and gave equivalent improvements in plant stand and yield.     

Effect of spraying techniques on the brown rot of peach fruit,and on black spot,powdery mildew and the two-spotted mite of apple trees

Application by hand-held equipment of the commercially recommended doses of proprietary formulations of captan (9.0 g a. i. per tree), mancozeb (10.8 g a. i. per tree), oxythioquinox (1.1 g a. i. per tree), and cyhexatin (1.8 g a. i. per tree), in spray volumes ranging from 0.225 to 9.0 litres per tree, gave commercial control of the brown rot of peach fruit, and of black spot (apple scab), powdery mildew and the two-spotted mite (Tetranychus urticae) of apple trees. Commercial control was also obtained using a quarter of the recommended doses when applied in 0.225 or 2.25 litres per tree. The residue of oxythioquinox on the leaves, immediately after applying 1.1 g a. i. per tree, doubled as the volume of spray was reduced from 9.0 to 2.25 litres per tree, and increased further when the volume was reduced to 0.225 litres per tree. It is suggested that some of the oxythioquinox ran off the trees at the higher volumes, and that less run-off at lower volumes resulted in higher chemical residues.     

苯醚甲环唑在套袋与不套袋苹果中的残留及消解动态

通过两年田间试验并结合气相色谱-电子捕获检测(GC-ECD)技术,研究比较了苹果套袋 和不套袋2种不同栽培方式下苯醚甲环唑在苹果中的残留及消解动态。结果表明:2011和2012年, 苯醚甲环唑在未套袋苹果中的原始沉积量分别为0.44和0.17 mg/kg,消解半衰期分别为12.8和15.5 d;2012年其在套袋苹果中的原始沉积量为0.056 mg/kg,半衰期为31.9 d。两年的试验表明,于苹果收获前35~42 d,按照10%苯醚甲环唑水分散粒剂的推荐剂量和1.5倍推荐剂量(有效成分分别为66.7和100 mg/L)施药2次和3次, 距末次施药后7 d采收,套袋和不套袋果实中苯醚甲环唑的残留量均低于我国最大残留限量(MRL)值0.5 mg/kg,其中套袋处理均低于0.03 mg/kg,表明苯醚甲环唑按照推荐剂量及次数施用是安全的;在套袋方式下,苯醚甲环唑残留量明显降低。     

机动弥雾法施用70%吡虫啉水分散粒剂防治小麦蚜虫的雾滴沉积密度与防效的关系

田间采用背负式机动弥雾机对70%吡虫啉水分散粒剂进行喷雾试验,证明若吡虫啉喷雾雾滴在小麦穗部形成一定的沉积密度即可有效防治麦蚜。当70%吡虫啉水分散粒剂用水稀释2 333倍(有效成分300 mg/L),雾滴密度在54,133和280个/cm2条件下,施药7 d后对麦蚜的防治效果分别为83.3% ,88.7%和93.7%;当药剂稀释1 167倍(有效成分600 mg/L),雾滴密度在75,142和291个/cm2条件下,7 d后对麦蚜的防治效果分别为88.1%,94.5%和96.5%。采用背负式机动弥雾机,采用常量150 L/hm2、低浓度(300 mg/L)喷雾时,小麦穗部、旗叶上的雾滴沉积密度分别为177±12,113±8个/cm2,沉积量分别为27.4±6.8,6.6±1.6 ng/cm2,地面流失率为12.8%,7 d后的防治效果为94.0%; 当采用低容量75 L/hm2、高浓度(600 mg/L)喷雾时,小麦穗部、旗叶上的雾滴沉积密度分别为127±13,91±7个/cm2,沉积量分别为29.8±1.2, 6.7±0.6 ng/cm2,地面流失率为10.6%,7 d后的防治效果为93.8%。生产中建议采用吡虫啉低容量75 L/hm2、高浓度600 mg/L喷雾,省工、省水、省时。     

Influence of formulation on spray deposit patterns,dislodgeable and penetrated residues,and persistence characteristics of fenitrothion in conifer needles

The influence of formulation on spray droplet spectra, deposit patterns, dislodgeable and penetrated residues, and persistence characteristics of fenitrothion in balsam fir needles was studied using three formulations containing different types of adjuvant. Spray was applied on to potted trees under controlled conditions in a laboratory chamber. Droplet size spectra and deposits were assessed using “Kromekote” cardlglass plate units. Foliar residues were measured by gas-liquid chromatography. The formulation containing polymeric adjuvants provided significantly larger droplets and higher foliar residues than those containing surfactants and co-surfactants. It also provided a higher ratio of dislodgeable-to-penetrated residues, and a slower initial rate of loss of fenitrothion. None of the formulations posed a long-term persistence problem because only very low amounts remained on foliage at 42 days post-treatment. The significance of these findings in terms of the possible increase in bioavailability of the pesticide via crawling contact is discussed.