Effect of the spray application technique on the deposition of entomopathogenic nematodes in vegetables

BACKGROUND: The present study compared entomopathogenic nematode delivery at the base of savoy cabbage and cauliflower, at the lower side of savoy cabbage and cauliflower leaves and in leek stems and the ground deposition using a five‐nozzle spray boom equipped with an ISO 08 flat fan, an air induction flat fan and Twinjet spray nozzles. Additionally, an air support system and a row application system were evaluated. RESULTS: Approximately 40% of the applied nematodes did not reach the foot of the cabbage plants. The use of an air support system or a row application system improved nematode deposition at the savoy cabbage base. Relative nematode deposition on the lower side of savoy cabbage leaves was 27.20%, while only 2.64% of the applied nematodes reached the lower side of cauliflower leaves. After spraying leek with a standard boom, a low relative nematode deposition (26.64%) was measured in the leek stem. Nozzle type affected the distribution of nematodes in droplet spots. CONCLUSION: Nozzle type has a minor effect on the number of entomopathogenic nematodes delivered on difficult‐to‐reach targets. The use of modified spray application techniques directing the spray to the target site are necessary to increase the chances of contact of entomopathogenic nematodes with their target. Copyright © 2011 Society of Chemical Industry     

Effects of nozzle type and spray angle on spray deposition in ivy pot plants

BACKGROUND: Fewer plant protection products are now authorised for use in ornamental growings. Frequent spraying with the same product or a suboptimal technique can lead to resistance in pests and diseases. Better application techniques could improve the sustainable use of the plant protection products still available. Spray boom systems—instead of the still predominantly used spray guns—might improve crop protection management in greenhouses considerably. The effect of nozzle type, spray pressure and spray angle on spray deposition and coverage in ivy pot plants was studied, with a focus on crop penetration and spraying the bottom side of the leaves in this dense crop. RESULTS: The experiments showed a significant and important effect of collector position on deposition and coverage in the plant. Although spray deposition and coverage on the bottom side of the leaves are generally low, they could be improved 3.0–4.9‐fold using the appropriate application technique. CONCLUSIONS: When using a spray boom in a dense crop, the nozzle choice, spray pressure and spray angle should be well considered. The hollow‐cone, the air‐inclusion flat‐fan and the standard flat‐fan nozzle with an inclined spray angle performed best because of the effect of swirling droplets, droplets with a high momentum and droplet direction respectively. Copyright © 2010 Society of Chemical Industry     

冠层推拨装置对喷杆喷雾机雾滴飘失与沉积特性的影响

喷杆喷雾机具有作业效率高、雾滴覆盖率高、沉积分布均匀、防治效果好等优点,是目前大田作物最主要的施药机具.但受作物冠层遮挡和侧风等气象条件的影响,导致喷杆喷雾机作业时雾滴难以穿透到植株中下部并伴随飘失.为改善喷杆喷雾机喷雾雾滴在作物冠层的穿透性并降低飘移量,本文优化设计了一种适用于大田作物的喷杆喷雾机冠层推拨装置.并分别...     

喷雾助剂对茎叶处理除草剂的增效机制及应用研究进展

农田草害的发生严重影响了农业生产和发展,使用除草剂进行化学防治是目前最省时省力和防除效果最好的除草方法.其中,茎叶处理除草剂因其具有不受土壤环境影响、按草施药、灵活和选择性高等优点,应用范围更广.然而,茎叶处理除草剂在喷雾施药过程中由于受到杂草叶片界面特性的影响,常出现药液迸溅、滚落、难以渗透等现象,导致除草剂用量增大...     

Rainfastness and adsorption of herbicides on hard surfaces

Herbicides are still used to control weeds on hard surfaces, including municipal, private and industrial sites. Used under unfavourable conditions, especially when rain occurs shortly after application, herbicides may run off to surface waters. Such losses of herbicides from hard surfaces are estimated to be much higher than for herbicides used in arable fields. In this study, three kinds of hard surface were evaluated: asphalt, concrete surface and gravel (fine and coarse). Three herbicides were applied: glyphosate, diuron and diflufenican. Adsorption isotherms of diuron and diflufenican to the three surfaces were determined. At different times after treatment with the herbicides, rainfall was simulated by use of a rain-droplet spray nozzle, and the run-off was collected for analysis. After this run-off event, the materials were immersed in water to measure desorption which, together with the compound in the run-off, gave a measure of the dislodgable residues. The apolar herbicides diuron and especially diflufenican adsorbed strongly to asphalt. The polar herbicide glyphosate lost 75% in run-off from asphalt but was adsorbed strongly to soil and concrete pavement.     

Efficacy of four corn (Zea mays L.) herbicides when applied with flat fan and air induction nozzles

Twelve field experiments were conducted over a 4 year (2002–2005) period to determine the influence of the herbicide dose, nozzle type, spray volume, and spray pressure on herbicide efficacy in field corn ( Zea mays L.). The control of Abutilon theophrasti (velvetleaf ), Ambrosia artemisiifolia (common ragweed), Chenopodium album (common lambsquarters), Amaranthus powellii (green pigweed), and Echinochloa crus-galli (barnyard grass) was improved with the use of full herbicide doses compared to half doses of bromoxynil, glufosinate, dicamba, and nicosulfuron. The yield was increased for bromoxynil, glufosinate, and nicosulfuron when the full herbicide dose was used. When applied at the manufacturer's recommended dose, flat fan nozzles, compared to air induction (AI) nozzles, provided better control of A. theophrasti , A. artemisiifolia , and C. album with bromoxynil, A. artemisiifolia and C. album with dicamba, and E. crus-galli with nicosulfuron. Bromoxynil, in relation to weed control, was the only herbicide that was affected by the water carrier volume. By increasing the spray pressure with an AI nozzle, there was an improvement in the control of A. theophrasti , A. artemisiifolia, and C. album with the application of bromoxynil and E. crus-galli with the application of nicosulfuron, with a yield increase with bromoxynil. Overall, this study concludes that the optimum nozzle type, water carrier volume, and spray pressure is herbicide- and weed species-specific.     

Flat fan and air induction nozzles affect soybean herbicide efficacy

Fifteen field experiments were conducted from 2002 to 2005 to determine the influence of the nozzle type, spray volume, spray pressure, and herbicide rate on herbicidal efficacy in soybean. There was no effect of the nozzle type on herbicidal efficacy with fomesafen, bentazon, glyphosate, and cloransulam‐methyl when applied at the manufacturer's recommended rate. The control of Echinochloa crus‐galli (barnyardgrass) with quizalofop‐p‐ethyl was improved when applied with flat fan (FF) nozzles compared with air induction (AI) nozzles. There was an increase in weed control with the FF nozzles compared with the AI nozzles in four of the 13 comparisons when the herbicides were applied at half the recommended rate, while in two situations, application with the AI nozzles resulted in improved weed control. With the FF nozzles, there was no effect of the water carrier volume on weed control with bentazon, glyphosate, and cloransulam‐methyl. The control of Abutilon theophrasti (velvetleaf) and Chenopodium album (common lambsquarters) with fomesafen and E. crus‐galli with quizalofop‐p‐ethyl was improved at the higher water carrier volume. With the AI nozzles, the control of A. theophrasti and Ambrosia artemisiifolia (common ragweed) with fomesafen and E. crus‐galli with quizalofop‐p‐ethyl was improved at the higher water carrier volume, while the control of A. theophrasti and Polygonum persicaria (ladysthumb) was improved with glyphosate at the lower water carrier volume. With the AI nozzles, the control of C. album with bentazon and E. crus‐galli with quizalofop‐p‐ethyl was improved at the higher spray pressure. There was no effect of the nozzle type on the soybean yield with glyphosate, cloransulam‐methyl, and quizalofop‐p‐ethyl. The use of the FF nozzles compared with the AI nozzles to apply fomesafen and bentazon increased the soybean yield by 6 and 7%, respectively. Based on this study, the optimum nozzle type, water carrier volume, and spray pressure is herbicide‐ and weed species‐specific.     

Newly Developed Low-pressure TeeJet Nozzles for Pesticide Application at Lower Water Volume and Reduced Wind Drift1

The development of TeeJet flat-jet nozzles in the 1960's has facilitated optimal herbicide application. The required accuracy of ± 15 % in transverse distribution was achieved by a nozzle spacing of 50 cm and a height above ground of 40-60 cm. Two problems remained: 1) to reduce volumes; 2)to limit drift yet further. The development of the low-pressure TeeJet has helped to solve these problems. The nozzle is constructed with a cylindrical tube which is ellipsoidal in cross-section at the input end and which narrows symmetrically to the axis to a flattened oval orifice at the output end. By this means 1) the spray angle of 110° can be achieved with a pressure of 1 bar; 2) better distribution is achieved at the edges of the jet, by comparison with the standard TeeJet; 3) a greater proportion of coarse droplets is achieved by comparison with 110° or 120° nozzles (nominal pressure 3 bar). It is accordingly possible to apply herbicides at volumes lower than the currently used 4001/ha. Trials have shown that, with few exceptions, water volume can simply be reduced to 1001/ha without any increased risk of drift     

Unkrautbekämpfung in Lupinen – Erkenntnisse aus 10 Jahren Lückenindikation

In Germany, cultivation of lupines traditionally takes place only in few federal states at sites with light/sandy soil conditions. Due to this fact, there only exist a small number of field trials to close gaps in chemical weed control via herbicides. The existing pre-emergence herbicides are not able to control all of the most common weed species sufficiently-they all show efficiency gaps against single weed species. Not any of the pre-emergence herbicides tested could achieve high efficiencies against Polygonum convolvulus. The best efficiency against P. convolvulus can be achieved after a sequence of a pre-emergence spray of 0,8–1,0 l/ha Fenikan and a post-emergence spray of 0,2 l/ha Tacco. Since Fenikan and Tacco are not approved for lupine, after approval the application only in lupine stocks for seed production is possible. By taking into account only the currently legal permitted herbicides, Gardo Gold and the tank mix Boxer?+?Stomp Aqua show the best broad effects. Benefits resulting from Gardo Gold can be obtained against Chenopodium album, Viola arvensis, Centaurea cyanus, while the tank mixes Boxer?+?Stomp Aqua show advantages against Galium aparine. From the pre-emergence herbicides tested, Successor T could be applied as an addition to improve the broad effect. In tank mixes with Gardo Gold, the most common weed species can be controlled well. However, with permission also this tank mix can currently only be applied in lupine seed stock production. In the near future weed control will only be possible with the currently existing and approved herbicides, because there are no new herbicides to expect that are compatible with corn, grain and lupine. Under suboptimal application conditions of soil herbicides, weeded lupine stocks can only be harvested after siccation.     

节节麦防除药剂及其增效助剂筛选

为筛选能有效防除节节麦Aegilops tauschii的除草剂及助剂,通过室内盆栽法评价11种除草剂对节节麦的防除效果,分析比较15种不同助剂对其中2种除草剂甲基二磺隆和异丙隆的增效作用,并明确其最适配比。结果显示,在供试11种除草剂中,甲基二磺隆和异丙隆对节节麦具有较的好防除效果,当其施药量分别为13、1 000 g（a.i.）/hm²时,对节节麦的鲜重抑制率分别达68.40%和76.46%,其余9种除草剂的防除效果较差,鲜重抑制率在4.62%~35.95%之间;筛选到对甲基二磺隆有显著增效作用的2种助剂——乙基和甲基酯植物油、有机硅408,其最适用量分别为甲基二磺隆喷液量的0.5%和0.2%（体积比）,增效分别为15.21%和26.52%;筛选到对异丙隆有显著增效作用的3种助剂——异十三醇聚氧乙烯醚、聚醚改性七甲基三硅氧烷、乙基和甲基酯植物油,其最适用量分别为异丙隆喷液量的0.1%、0.05%、0.25%（体积比）,增效分别为26.24%、21.80%和25.99%。表明甲基二磺隆、异丙隆可用于防除节节麦,添加助剂可进一步提高其对节节麦的防除效果。     

The use of separate root and shoot tests in the screening of herbicides for strawberries

The tolerance of strawberries to herbicides was tested by applications to the roots of plants growing in sand and by foliage applications to plants grown in compost, and compared with tolerance in the field. Dimefuron was safe as a foliar application but much more toxic than simazine when applied in sand or in the field. Metamitron caused slight injury as a foliar spray; in sand and in the field it was intermediate in toxicity between simazine and lenacil. At normal rates propachlor was safe as a foliar spray and much safer than lenacil when applied in sand. High rates had no adverse effect in the field. Ethofumesate and pendimethalin caused some temporary stunting when applied to foliage, but were less toxic than lenacil when applied to roots in sand. Field applications of both herbicides at 1–1.5 kg/ha were safe. Foliage sprays of bentazone, oxadiazon and oxyfluorfen severely damaged the sprayed leaves, but these herbicides were less active than lenacil when applied to the roots. In the field they caused severe leaf damage, but by the end of the growing season the plants had recovered. The experiments demonstrated the value of separate root and shoot activity tests for indicating which herbicides merit further field testing.     

HERBICIDES AS FERTILIZER ADDITIVES

Summary. Granulated compound fertilizers were tested as solid carriers for a variety of herbicides known to be active when applied as liquids.
Pasture and cereal experiments with 2,4-D and MCPA as fertilizer additives indicated considerable loss of herbicidal activity in comparison with spray formulations.
Residual herbicides such as TCA, propham and diuron retained their activity when added to fertilizer for application to root crops. The most effective of the herbicides used as fertilizer additives were TCA and propham, both of which gave good control of Avena fatua in sugar beet, and a mixture of chlorpropham and diuron gave promising results as a general weed control treatment in carrots.
It is concluded that the addition of these or similar herbicides to fertilizer granules may have advantages over conventional spray formulations for those crops which require broadcast pre-sowing applications of herbicides and fertilizer. For such crops the use of a granular fertilizer as the carrier instead of inert material could also have advantages over conventional granular herbicides, particularly by reducing transport and application costs.     

雾滴密度与喷雾方式对毒死蜱防治褐飞虱效果的影响

分别选用实心圆锥雾和扇形雾TP6501E两种喷头,以3WP-2000型行走式喷雾塔模拟对水稻植株压顶喷雾和侧向喷雾,探究雾滴密度、喷雾方式对48%毒死蜱乳油防治褐飞虱效果的影响。结果表明：压顶喷雾当底层雾滴密度分别达到99.4个/cm^2和94.9个/cm^2,且48%毒死蜱乳油有效剂量分别高于68.00 mg/m^2和55.64 mg/m^2时,对褐飞虱的防治效果达80%;侧向喷雾当底层雾滴密度分别在10.4～49.0个/cm^2和12.3～55.4个/cm^2范围内,且48%毒死蜱乳油有效剂量分别在41.21～82.42 mg/m^2和72.12～82.42 mg/m^2区间内对褐飞虱的防治效果均高于80%。相同有效剂量条件下,侧向喷雾的防效高于压顶喷雾。采用侧向喷雾方式时,水稻基部较易获得高密度雾滴,药剂在低有效剂量条件下即可取得预期防治效果。     

Characterization of irrigator emitter to be used as solid set canopy delivery system: which is best for which role in the vineyard?

Background

The timely and flexible treatment of solid set canopy delivery systems (SSCDS) is expanding. Laboratory and field trials were conducted to evaluate the performance of three different irrigators (Pulsar™ system and nozzle combination), typically used in anti-frost and irrigation in vineyards/apple orchards, for plant protection product (PPP) delivery in a Guyot-trained trellised vineyard.

Results

Results showed that irrigator setups perform best when matched to the task—flat fan emitters for horizontal spray application (canopy top) and circular emitters for middle and low canopy application. A combination configuration of a double-sided flat fan and circular emitter system was indicated as the best option for homogenous coverage and minimal ground losses.

Conclusion

The tested emitters hold promise for SSCDS delivery of PPPs in vineyards. Further validation of the alternative use of this technology is warranted. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

离心雾化低容量喷杆喷雾与常量喷雾对比研究

为探究装配离心雾化喷头的喷杆喷雾机在小麦田植保作业中的适用性,研发了一种基于低容量离心雾化技术的喷杆喷雾机(BSC),以添加诱惑红示踪剂的3种药剂（5%己唑醇悬浮剂、40%氧乐果乳油和50%吡蚜酮水分散粒剂）的混合复配制剂为供试药液,与装配液力式喷头的背负式喷雾器(KSH)、喷杆喷雾机(BSH)以及装配离心雾化喷头的背负式喷雾器(KSC)进行田间施药对比试验,分析了4种机具的主要作业效果指标——雾滴沉积分布均匀性、小麦冠层药液穿透性、作业效率以及防治效果。结果表明:对于沉积均匀性,离心雾化低容量喷杆喷雾与常量喷雾无显著性差异,而装配离心雾化喷头的背负式喷雾器的沉积均匀性低于其他3种机具;与常量喷雾相比,离心雾化方式有效提高了药液的冠层穿透性,最多可提高2.9倍;与常量喷杆、低容量离心背负和常量背负式喷雾器相比,低容量离心喷杆喷雾机的作业效率分别提高0.5倍、5.6倍和18.6倍;对比空白处理,低容量离心喷雾和常量喷雾方式防治效果显著,但两者之间无显著性差异。该研究可为低容量施药技术、超低容量施药技术和离心雾化技术在喷杆喷雾机上的应用提供参考。     

水稻田几种常用喷雾法的药液沉积率测定

对稻区常用的几种喷雾方法所产生雾滴的沉积率进行了测定。手动喷雾器的大容量喷雾法的药液沉积率虽高,但药剂有效成份之沉积率较低。低容量喷雾法的药液沉积率较低,而药剂有效成份沉积率较高。对稻区流行的喷雨法和水唧简法的沉积率不稳定和偏低,进行了评价。湿润展布剂对于药液的沉积能力有显著影响,在有湿润展布剂时,药液沉积率显著提高。不合湿展剂时,增加喷雾量对于药液沉积率的提高作用较小。大容量喷撒法有大量农药散落到田水中,而在株冠层内的穿透和分布能力并不好。     

Influence of application volume on the efficacy of clodinafop-propargyl and fenoxaprop-P-ethyl on oats

The influence of application volume on the efficacy of clodinafop‐propargyl and fenoxaprop‐P‐ethyl on cultivated oats (Avena sativa) was studied in the glasshouse. Both herbicides were more efficacious when applied in 75 L ha^?1 than in 300 L ha^?1, with 11002 and 11006 nozzles respectively. However, when the same two volume rates were created by varying the speed of a 11003 nozzle, clodinafop‐propargyl efficacy was not affected by application volume, whereas fenoxaprop‐P‐ethyl remained more efficacious at 75 L ha^?1. This suggests that in the first experiment, fenoxaprop‐P‐ethyl efficacy was affected by changes in both spray quality and concentration, whereas only the former influenced clodinafop‐propargyl efficacy. The hypothesis that the fenoxaprop‐P‐ethyl formulation was more influenced by concentration than clodinafop‐propargyl was supported by dynamic surface tension studies and measures of active ingredient retention by oat plants. Within the practically relevant concentration range considered, surface activity of clodinafop‐propargyl remained low, with little influence on herbicide retention. In contrast, depending on the concentration, surface activity of fenoxaprop‐P‐ethyl was below or above levels that were critical for its retention. Although these differences may not be as apparent in the field as in the glasshouse, our study certainly indicates that both clodinafop‐propargyl and fenoxaprop‐P‐ethyl are herbicides favoured by low application volumes.     

The influence of volume rates on the activity of glyphosate and difenzoquat assessed by a parallel-line assay technique

The influence of volume rate and nozzle size on the activity of difenzoquat and glyphosate against outdoor, pot-grown wild oats and barley plants, respectively, was assessed using a parallel-line assay technique. The results showed that the assumption of parallel dose-response curves for difenzoquat and glyphosate was not rejected in either experiment. An inverse relationship between herbicidal activity and volume rate was found with both herbicides, but volume rate had a more pronounced impact on glyphosate activity than on difenzoquat activity. For a given spray volume, no impact of nozzle size on the activity of glyphosate was found. The advantages of applying the parallelline assay in studies of the influence on herbicide activity of factors not supposed to affect the mode of action of the herbicide are discussed.     

Development and assessment of a novel servo-controlled spraying system for real time adjustment of the orientation angle of the nozzles of a boom sprayer

Background

Pesticide spray drift, which is the movement of pesticide by wind to any location other than the intended area, is hazardous to human, animal, food safety and environmental health. It is not possible to completely eliminate spray drift during spraying with field crop sprayers, but spray drift can be reduced by developing new technologies. The most common methods to reduce spray drift are carrying the droplets to the target with air-assisted spraying, electrostatic spraying, preferring air induction nozzles and boom shields. With these methods, it is not possible to make a change on the sprayer depending on the wind intensity during spraying. In this study, a novel servo-controlled spraying system was designed and developed to change the nozzle orientation angle in the reverse direction of the wind current to reduce the ground spray drift in real time and automatically in a wind tunnel. The displacement in the spray pattern (D_c) was used as a ground drift indicator for each nozzle to evaluate the spray drift.

Results

The developed system, operated by LabVIEW software, calculated different nozzle orientation angles depending on nozzle types, wind velocities and spraying pressures. Orientation angles calculated for different test conditions achieved in reduction were up to 49.01% for XR11002 nozzle, 32.82% for AIXR11002 nozzle and 32.31% for TTJ6011002 nozzle at 400 kPa spray pressure and 2.5 m s⁻¹ wind velocity.

Conclusion

The developed system, which has a self-decision mechanism, calculated the nozzle orientation angle instantaneously according to the wind velocity. It has been observed that the adjustable spraying nozzle system, sprayed with high precision towards the wind in the wind tunnel, and the developed system have advantages compared to conventional spraying systems. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

AN IMPROVED METHOD OF CONTROL OF PASPALUM CONJUGATUM WITH AMITROLE-T AND PARAQUAT

Summary. Paraquat, amitrole-T and disodiumn methylarsonate (DMA) were evaluated for the control of the stoloniferous grass Paspalum conjugatum in young rubber plantations in Malaya. The herbicides were tested alone, in mixtures and in split applications. Paraquat at 0–5 lb/ac gave good initial desiccation but regeneration was extremely rapid and repeated sprays of 0–25 lb/ac were required for a long period of suppression. Amitrole-T at 15 lb/ac was very slow to act but gave complete kill after 10 weeks. DMA at 8–12 lb/ac gave marked suppression, but regeneration rapidly developed after 8 weeks. Mixtures of either amitrole-T or DMA with paraquat gave less than the expected additive effects of the components, indicating an antagonistic action. Sub-lethal rates of amitrole-T or DMA applied to regenerating shoots after paraquat treatment gave results inferior to those from higher rates of the herbicides alone.
When paraquat was applied 2 weeks after an initial sub-lethal dose (0.375 lb/ac) of amitrole-T, desiccation was rapid and complete eradication was achieved; this did not occur when a low rate of DMA was used as the first spray. In terms of both speed of kill and final effect, a split application of a low rate of amitrole-T followed by paraquat was the most effective treatment. A possible explanation of the apparent synergism between amitrole-T and paraquat applied in this way is advanced and suggestions for further work outlined.
Une méthode améliorée pour la lutte centre Paspalum conjugatum avoc l'amitrole-T et le paraquat