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1.
多旋翼植保无人机喷施新烟碱类杀虫剂对蜜蜂的飘移风险   总被引:2,自引:0,他引:2  
为明确植保无人机喷施新烟碱类杀虫剂对非靶标生物蜜蜂的飘移风险,在田间试验场景下,比较分析多旋翼植保无人机和背负式电动喷雾器喷施新烟碱类杀虫剂时的雾滴飘移量及对蜜蜂的影响。结果表明:应用背负式电动喷雾器和多旋翼植保无人机进行施药作业时,距离施药区下风向5 m处的雾滴飘移率分别为0.50%和23.98%;而多旋翼植保无人机施药时,即使距离施药区下风向17 m处的雾滴飘移率仍高达2.79%,且多旋翼植保无人机施药时的飘移总量显著高于背负式电动喷雾器。喷施新烟碱类杀虫剂时,应用背负式电动喷雾器作业时距离下风向5 m处的蜜蜂在施药后1 d内的死亡数量为75头,分别是距离下风向17 m处和对照组的2.4倍和1.8倍,施药后2~8 d内蜜蜂的死亡数量与对照组无明显差异;应用多旋翼植保无人机作业时距离下风向5 m处的蜜蜂在施药后1 d内的死亡数量为4 721头,分别是距离下风向17 m、29 m处和对照组的3.0倍、6.1倍和112.4倍,施药后2~8 d内蜜蜂的死亡数量明显降低,但距离施药区较近的蜜蜂其死亡数量明显高于对照组,表明多旋翼植保无人机喷施新烟碱类杀虫剂对蜜蜂存在较高的飘移风险。  相似文献   

2.
今年5月中旬,公安县埠河镇雷洲村20hm~2棉苗发生药害。据调查了解,原来是雷洲村60hm~2芦苇承包给本村个体农户管理。承包户为了防除芦苇杂草,先后于4月底、5月10日各喷1次2,4—滴丁酯除草剂。喷药后,由于2,4—滴丁酯挥发的蒸气漂移到毗邻芦苇滩的棉苗上,使棉苗产生轻重程度不  相似文献   

3.
为评估植保无人机低空低容量施药下的喷雾飘移风险,以国内市场主流机型电动多旋翼植保无人机为施药机械,研究不同环境风速及飞行参数(高度和速度)下喷雾雾滴飘移特性,构建雾滴飘移率与飘移距离之间的函数关系,并将测试结果与侧风速度及飞行参数进行相关性分析和回归分析。结果表明:在温度为16.5~25.2℃,相对湿度为21.7%~64.4%的条件下,植保无人机喷雾地面雾滴飘移率与下风向距离的关系满足指数函数λ=a·ebx,相关系数R2均大于0.914;在侧风速度为1.1~7.0 m/s的条件下,雾滴累计飘移率在13.0%~56.2%之间,90%飘移雾滴沉降在喷雾区下风向7.0~27.3 m距离范围内;侧风速度、飞行高度均与雾滴累计飘移率和90%累计飘移距离呈极显著正相关,且3个因素对雾滴飘移率的影响大小为侧风速度 > 飞行高度 > 飞行速度,对90%累计飘移距离的影响大小为飞行高度 > 侧风速度 > 飞行速度,对喷幅内沉积率的影响大小为飞行高度 > 侧风速度 > 飞行速度。研究结果可用于多旋翼植保无人机实际作业中雾滴飘移风险的控制及飘移缓冲距离的确定。  相似文献   

4.
无人机低空喷施苯氧威防治亚洲玉米螟初探   总被引:4,自引:0,他引:4  
使用TXC-8-5-0-1八旋翼无人机喷洒3%苯氧威乳油防治穗期玉米螟,研究该无人机飞行高度、施药液量以及加入雾滴蒸发抑制剂等因素对雾滴在玉米冠层的沉积分布及对玉米螟防效的影响。结果表明,在0.5~2 m范围内,该无人机飞行高度对喷幅无显著影响;防治玉米螟最佳飞行高度为距离玉米冠层1 n;最佳施药液量为12 L/hm~2,此条件下雾滴在雌穗上的沉积密度为(20.4±3.0)个/cm~2,防治效果为(79.6±3.1)%;加入雾滴蒸发抑制剂可以把玉米雌穗上的雾滴沉积密度提高至(25.5±4.9)个/cm~2,防治效果提高至(83.3+5.1)%。  相似文献   

5.
西洋参疫病菌的水滴飞溅传播规律   总被引:1,自引:0,他引:1  
本项研究通过实验模拟手段揭示了水滴飞溅散布对西洋参疫病菌传播的机制。从定量的角度确立了西洋参疫病菌传播数量与水平距离、水滴碰撞速率的数学模型: Ln(Y)=b_0 b_1D b_2V 在自然雨滴的直径范围内,垂直下落高度在3.5m以内,飞溅传播直径约1m,在三维空间里,以低于碰撞源水平面的传播效果最为明显。  相似文献   

6.
小麦是我省主要栽培作物之一,产量高,面积大。近几年来,由于连作比例增加,阔叶杂草危害日趋严重,致使产量大幅度下降。生产上常以2,4—D 丁酯防除,但养麦蔓(polyo-num convolvulus L.)等一些恶性阔叶杂草,对2,4—D 丁酯产生了很强的抗性,加大剂量也很难防除,新引进的百草敌对其防效很好。为扩大杀草谱,提高杀草效果,进而提出2,4—D 丁酯与百草敌混用,但混用比例和使用时期一直没有彻底解决。为此,我们于1984~1986年进行了试验研究,旨在探索投资少、产量高、收益大的除草技术,为经济合理用药提供科学依据。  相似文献   

7.
2,4—D 丁酯的分析方法,目前采用化学滴定法(碱解后用酸回滴)。但因其杂质影响分析结果不准确,分析结果偏高,甚至有些还会得出错误的结果。如:我们分析内蒙古生资公司送检两个72%的2,4—D 丁酯乳油样品(81—141 81—142)其结果:  相似文献   

8.
<正>2,4-滴丁酯为苯氧乙酸类激素型选择性除草剂,对双子叶杂草敏感,对禾本科植物相对安全。因其在使用过程中有较强的挥发性,药剂雾滴可在空气中飘移较远,从而对周边敏感农作物或树木产生影响,易导致药害事故。近年,因2,4-滴丁酯产生的药害接连不断,并有上升趋势,引发农药生产、经营和使用者之间的纠纷、群众上访,对农业生产产生较大危害。一些地方政府、管理部门和农药使用者呼吁禁止或限制2,4-滴丁酯的使用。为此,在归纳总结了2,4-滴丁酯使用技术要求的基础上,分析产生药害的原因,提出了进一步加强管理的建议,供大家讨论借鉴。  相似文献   

9.
我市麦田杂草长期以来一直以藜、葎草为主,化学除草主要应用2,4-D 丁酯,由于2,4—D 丁酯的长期使用,杂草的抗药性有明显增强,2,4—D 丁酯用量从70年代的每亩30毫升,上升到现在的每亩50毫升甚至75毫升。一些抗性群落也相继出现,如:播娘蒿、麦瓶草、离子草、麦家公、野燕麦、卷茎蓼等。这些杂草生命力强,繁殖量大,对小麦危害严重。如麦瓶草最高每平方米达1800多株,造成小麦减产70%以上,卷茎蓼每平方米达300余株,造成小麦减产80%以上。2,4—D 丁酯对上述杂草防效很差,甚至无效,致使麦田杂草发生扩展很快,1985年抗性杂草仅零星发生。到1989年已造  相似文献   

10.
以黑龙江不同积温带的3个大豆主栽品种‘东农52’、‘合丰55’、‘黑河48’为材料,运用盆栽试验方法,在大豆播后苗前施用不同剂量的2,4-滴丁酯进行土壤处理,探讨了2,4-滴丁酯对不同大豆品种的产量及产量构成因素的影响。结果表明:2,4-滴丁酯对供试3个大豆品种的百粒重均无影响;2,4-滴丁酯造成大豆减产的处理,大豆单株粒数必然减少,而单株荚数、有效荚数不一定减少,造成大豆减产的主要原因是大豆单株粒数减少。可见,施用2,4-滴丁酯是否造成大豆减产可通过调查大豆单株粒数进行评判;供试3个大豆品种对2,4-滴丁酯的敏感性不同,2,4-滴丁酯施药量达1 080 g/hm2时引起‘黑河48’减产,达1 620 g/hm2时引起‘东农52’减产,达2 160 g/hm2时才引起‘合丰55’减产。供试大豆品种对2,4-滴丁酯的敏感性顺序为:‘黑河48’>‘东农52’>‘合丰55’。  相似文献   

11.
Summary. 2,4-D-amine, 2,4-D ethyl ester, 2.4-DB-potassium. MCPA-sodium, diquat and a 1:1 mixture of 2,4,5-T butyl ester and 2,4-D ethyl ester were applied to the tropical pasture legume Centrosema pubescens Benth. (centro) grown either alone or with Panicum maximum Jacq. (guinea grass). Even at 0.5 Ib/ac (total) the 2,4,5-T/2,4-D mixture caused severe damage to seedling and mature centro. 2,4-D-amine, 2,4-D ethyl ester and 2,4-DB-potassium were less damaging and there were only slight differences in response to these. Diquat at 0.25 Ib/ac desiccated centro seedlings, but most plants survived and grew satisfactorily. There was some evidence that the growth of mature centro was depressed least when the herbicides were applied during vegetative quiescence.
Application just after the start of flowering altered the flowering pattern but did not reduce seed yields significantly. 2,4-D-amine at 0.75 and 1–5 lb/ac and 2,4-D ethyl ester at 1.5 Ib/ac decreased the percentage germination of abraded seed. Diquat 0.25 Ib/ac applied at the start of flowering caused significant increases in top growth and seed pod numbers, possibly the result of modification of the normal flowering pattern.  相似文献   

12.
为研究多旋翼植保无人飞机施药时农药雾滴飘移规律以及施药作业人员职业暴露情况,依据喷雾飘移田间测试国际标准ISO22866和人体暴露贴片测试法,对多旋翼植保无人飞机和电动背负式喷雾器在水稻田喷施氯虫苯甲酰胺和苯醚甲环唑时的农药雾滴飘移量及施药作业人员人体农药沉积量进行了对比测试和分析评价。结果表明:在本试验环境条件下,多旋翼植保无人飞机在作业速率4 m/s和作业高度1.8 m参数下施药时,在距施药区下风向边界0~30 m范围内地面均有农药飘移性沉积,30 m处氯虫苯甲酰胺飘移率为0.9%,而背负式喷雾器施药的飘移量则主要集中在距施药区0~3 m区域内,3 m以外区域飘移率均≤0.6%;背负式喷雾器在距施药区5 m以及10 m远处空中不同高度的飘移量均小于0.001 μg/cm2,多旋翼植保无人飞机在距施药区5 m远处空中的飘移量大于10 m处,并且在垂直分布上,距冠层2 m左右 (无人飞机的飞行高度) 处飘移量最多。结合两种施药机具的雾滴粒径(背负式喷雾器DV50 值为149.4 μm,多旋翼植保无人飞机DV50 值为115.3 μm) 分析,无人飞机的雾滴具有更高的飘移潜力。由于实现了人机分离,多旋翼植保无人飞机进行作业时人体暴露量很低,而背负式喷雾器施药时对作业人员身体各部位均会造成一定的暴露,其中以手前臂和腿部正面暴露最为严重,在施用苯醚甲环唑时,右前臂背面暴露量最高,达到15.19 μg/cm2。本文中针对多旋翼植保无人飞机喷雾作业时在下风向的飘移沉积研究方法和试验结果,以及对多旋翼植保无人飞机施药过程中职业暴露的研究,可为农药喷雾作业缓冲区距离确定和人员作业安全评估提供参考。  相似文献   

13.
There are many diverse views about the effects of wind on aircraft sprays. Some operators wish to spray only when the air is still, others will not spray unless the wind speed is at least 3 m/s. The basis of this difference is the fear of, as against the use of, the downwind movement of droplets. This note uses a simple model of droplet behaviour in a wind to try to predict the deposit distributions downwind of a spraying aircraft. The results demonstrate that the level of turbulence caused by the wind blowing over the earth's vegetation reduces the downwind distance most small drops travel before being captured. Trees create more turbulence than cereal crops, which create more turbulence than bare earth or short grass. The deposit density at a given distance downwind reduces with decrease in aircraft flying height, wind speed and smoothness of the canopy. It remains roughly constant with increasing droplet size until a critical diameter is reached when it falls rapidly with increase in droplet size. This critical size depends upon windspeed and turbulence intensity. A downwind buffer zone between the spray area and a sensitive crop is desirable and its minimum size can be determined using the techniques discussed in the paper.  相似文献   

14.
Effects of droplet size and carrier volume on foliar uptake and translocation of gibberellic acid (GA3) and 2,4-D were investigated. Simulated spray droplets were applied to primary leaves of 10-day-old Phaseolus vulgaris (cv Nerina) in droplet sizes and carrier volumes ranging from 0.5 to 10 μl and 10 to 200 μl per leaf, respectively. Doses of GA3 (2 μg per leaf) and 2,4-D (100 μg per leaf) were held constant. Total uptake of GA3 approached a penetration equilibrium within 24 h after application, but uptake of 2,4-D continued to increase. Decreasing droplet size and/or increasing carrier volume increased GA3 and 2,4-D uptake. Translocation to stem and roots was positively related to total uptake. A positive linear relationship between the logarithm of the total droplet/leaf surface interface area and 2,4-D uptake or translocation was found, but for GA3 this relationship was quadratic. Potential mechanisms of the effects of spray application factors on foliar uptake are discussed. © 1999 Society of Chemical Industry  相似文献   

15.
Bioassays were adapted to investigate effects of droplet size and carrier volume on performance of daminozide, gibberellic acid (GA3) and 2,4-D using Phaseolus vulgaris L. as a model system. Response to plant growth regulators was indexed by inhibition (daminozide), promotion of internode elongation (GA3) or ethylene production (2,4-D). Elongation of first plus second internodes above primary leaves was evaluated 14 days after treatment of primary leaves, while ethylene production was determined from head-space samples of incubated leaves 24 h after treatment. Daminozide inhibition of internode elongation was related to decreased cell size and number in pith and epidermis (range 49–70% of the untreated control). GA3 increased cell size and number in both tissues 2·3- to 4·8-fold. Responsiveness to daminozide and 2,4-D markedly decreased as seedling age increased from 8 to 12 days, but responsiveness to GA3 increased. Decreasing droplet size (10–0·5 μl) and increasing carrier volume (10–200 μl per leaf) at constant dose of daminozide (100 μg per leaf) and 2,4-D (100 μg per leaf) significantly increased performance, but had little effect on performance of GA3 (2 μg per leaf). Effects of application factors on performance were related to their effects on the interface area between droplets and leaf surface. Significant positive linear relationships were obtained between plant response and the logarithm of the droplet/leaf interface area for all growth regulators. © 1998 Society of Chemical Industry  相似文献   

16.
Control of Avena fatua with tralkoxydim was significantly reduced in glasshouse experiments when the herbicide was tank-mixed with either 2,4-D amine or bentazone. Antagonism increased with increasing rates of these broadleaf herbicides in the tank-mixture and it could, in turn, be decreased by increasing rates of tralkoxydim. When herbicide solutions were applied to single leaves with a micropipette applicator, bentazone was antagonistic only when mixed in the same droplet with tralkoxydim and not when the two herbicides were applied adjacently in separate droplets. In contrast, both separate and combined applications of 2,4-D amine and tralkoxydim were antagonistic. There was no antagonism when mixtures with either 2,4-D amine or bentazone were applied between the leaf sheath and culm. Antagonism could be circumvented by sequential applications of the herbicides. When tral-oxydim was applied first, there was no loss of A. fatua control if bentazone application was delayed 0.5 h or if 2,4-D amine was delayed 24 h. Results suggest that bentazone affects only cuticular penetration of tralkoxydim, whereas 2,4-D amine also influences subsequent translocation.  相似文献   

17.
The effects of several herbicides for broadleaved weed control on glyphosate (n-phosphonomethyl glycine) phytotoxicity to wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and wild oats (Avena fatua L.) were studied in the greenhouse. In tank mixtures, dicamba (3,6-dichloro-o-anisic acid), 2,4-D (2,4-dichlorophenoxy-acetic acid) and bromoxynil (3,5-dibromo-4-hydroxy benzonitrile) reduced the phytotoxicity of threshold rates of glyphosate on all three species. With increasing rates of the herbicides for broadleaved weed control relative to a fixed rate of glyphosate, there was a general trend towards increased antagonism. Increasing glyphosate rates above the threshold level in mixtures containing a fixed rate of herbicides for broadleaved weed control overcame the antagonism. Both the inert and active ingredients of 2,4-D amine and ester appeared to be involved in the antagonism. There was no reduction in glyphosate phytotoxicity on the annual grasses when 2,4-D or bromoxynil were sprayed sequentially at various times in relation to glyphosate. When droplets of bromoxynil and glyphosate were placed side by side on a leaf, glyphosate phytotoxicity was not reduced, whereas when the two herbicides were mixed and applied as one droplet, considerable reduction in glyphosate phytotoxicity occurred. These results suggest that the reduction in glyphosate phytotoxicity caused by tank mixing with herbicides such as 2,4-D, bromoxynil and dicamba may be due to a physical or chemical incompatability within the tank mixture rather than to a biological interaction in the plant.  相似文献   

18.
为明确2,4-滴异辛酯的环境行为规律,采用室内模拟试验方法,研究了2,4-滴异辛酯在不同温度、pH值、水体及初始浓度下的水解特性及其在不同pH值、水体、光源和初始浓度下的光解特性。结果表明:中性 (pH = 7) 条件下,初始质量浓度为5 mg/L的2,4-滴异辛酯在15、25 和35 ℃ 下的水解半衰期分别为346.6、231.0和173.3 h;25 ℃下,5 mg/L的2,4-滴异辛酯在pH值分别为4、7 和9 的缓冲溶液中的水解半衰期分别为77.0、231.0 和138.6 h;2,4-滴异辛酯在稻田水、自来水和河水中的水解速率高于其在蒸馏水中的水解速率,4 种条件下的半衰期分别为23.1、25.7、40.8 和63.0 h;初始质量浓度分别为1、3和5 mg/L的2,4-滴异辛酯在pH值为7的缓冲溶液中的水解半衰期分别为231.0、173.3和138.6 h。300 W汞灯照射下,2,4-滴异辛酯在酸性条件下的光解速率大于其在中性和碱性条件下,半衰期分别为49.5、77.0 和138.6 h;2,4-滴异辛酯在河水和稻田水中的光解速率高于其在自来水和蒸馏水中的光解速率,4 种条件下的半衰期分别为6.7、7.6、43.3 和46.2 h;2,4-滴异辛酯在不同光源下的光解速率依次为500 W汞灯 > 300 W汞灯 > 500 W氙灯;初始质量浓度分别为1、3和5 mg/L的2,4-滴异辛酯在pH值为7的缓冲溶液中的光解半衰期分别为63.0、43.3和40.8 h。2,4-滴异辛酯水解及光解的主要产物是2,4-滴,其降解机制主要是酯水解反应。研究结果可为2,4-滴异辛酯的合理使用及其环境风险评估提供参考。  相似文献   

19.
There is a pressing need to quantify more fully the fate of ULV spray droplets dispersed over agricultural crops. For this purpose, field experiments were performed under various meteorological conditions of wind speed and turbulence level. Quantified atomizers were employed, giving known droplet diameter spectra. Vertical profiles of droplets impacting onto thin cylindrical collectors were measured at many stations up to 160 m downwind and at heights up to 12 m; they are presented in graphical form. They are also compared with available diffusion theories.  相似文献   

20.
Insecticide-resistant mosquito fish (Gambusia affinis) were found to be slightly more tolerant to two thiol esters of 2,4-dichlorophenoxyacetic acid (2,4-D) than were fish of a susceptible population. DEF (S,S,S,-tributyl phosphorotrithioate), at 0.1 ppm for 24 hr, slightly decreased the toxicity of both esters to both populations. Comparison of esterase activities in gill and liver preparations showed that the resistant fish had lower levels of liver esterases than the susceptible fish, but results with gill preparation were not consistent. With the ethyl thiol ester, susceptible fish had the higher activity, but with butyl thiol ester, resistant fish had the higher activity. DEF inhibited activities in both tissues of both populations, but inhibition was appreciably greater in the liver. Results suggest that (i) hydrolysis in the liver activaties 2,4-D esters, (ii) hydrolysis in the gill is a detoxication reaction, (iii) the slight increase in tolerance in the insecticide-resistant fish is primarily the result of decreased activation, and (iv) antagonism by DEF is the result of a greater inhibition of activation than of detoxication.  相似文献   

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