Does the Use of Adjuvants Alter Surface Tension and Contact Angle of Herbicide Spray Droplets on Leaves of Sida spp.?

Santos, Renata T. S.; Ferreira, M. C.; Viana, Rafael Gomes

doi:10.1590/s0100-83582019370100082

Cited by 12 publications

(10 citation statements)

References 15 publications

(21 reference statements)

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“…The lowest SCA values for Air/eggplant leaf interface were 20.6, 16.9, 14.2, 22.1, 18.9, 23.4 and 13.6 o at concentrations of 0.4, 0.6, 0.6, 0.4, 0.8, 0.6 and 0.4g/L respectively, and for Air/cucumber leaf interface were 22.8, 15.7, 27.6, 25.9, 19.7, 23.2 and 14.3 o at concentrations of 0.8, 0.8, 0.8, 0.6, 0.6, 0.8 and 0.6g/L for cucumber using TEA, liquid soap, glycerin, Arabic gum, molasses, urea and Rixi film respectively. These results are in agreement with that obtained by Santos et al (2019).…”

Section: Effects Of the Suggested Adjuvants On Static Contact Anglesupporting

confidence: 93%

Evaluation of Some Adjuvants in Improving Foliar Fertilizers

Omran

Ibrahim

Mohamed

et al. 2021

Arab Universities Journal of Agricultural Sciences

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A series of lab and field experiments were carried out to evaluate the possibility of using some substances as adjuvants added to the foliar fertilizer tank to improve fertilizer application and use efficiency. Each of the suggested substances was prepared in 10 concentrations treatments, ranging between 0.05 and 2g/L. The effect of each concentration on static surface tension and static contact angle in liquid/air/glass and solid plant leaves/air interface were used to evaluate and find out the optimum concentration of each substance to be used as adjuvant. An Adjmix-D1 was prepared using 0.6g/L Triethanolamine and 0.6g/L liquid soap as surfactants, 0.6g/L glycerin as a humectant, 0.6 g/L Arabic gum as a sticker and 0.6g/L urea as a penetrator. The obtained results showed that fruit yield as well as N, K, Fe, Zn and Mn contents in white eggplants and cucumber leaves are positively increased by the applications of improved foliar fertilizers (IFF). This increase can be arranged in the following descending order: Adjmix-D1 > Adjmix-D2 > Liquid soap > Rixi film > Triethanolamine. It could be concluded that the Adjmix-D1 can be used as an effective adjuvant for improving foliar fertilizer application efficiency.

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Section: Effects Of the Suggested Adjuvants On Static Contact Anglesupporting

confidence: 93%

Evaluation of Some Adjuvants in Improving Foliar Fertilizers

Omran

Ibrahim

Mohamed

et al. 2021

Arab Universities Journal of Agricultural Sciences

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“…Therefore, reducing the CA of the spraying liquids to facilitate them spreading on leaf surface is an important way to reduce off-target deposit ( Melo et al, 2015 ). Most tank-mix adjuvants aim for reducing evaporation, spray drift, and volatilization and improving pesticide’s ability to spread and stick on the target surface by reducing CA ( Celen, 2010 ; Melo et al, 2015 ; Santos, Ferreira & Viana, 2019 ). The addition of tank-mix adjuvant(s) into a pesticide product or pesticide spray mixture contributes to the reduction of spraying droplets’ CAs, which is expected to reduce off-target deposit effectively and obtain a better distribution ( Griesang et al, 2017 ; Mehdizadeh, Mehdizadeh & Baghaeifar, 2020 ; Meng et al, 2018 ; Sobiech et al, 2020 ).…”

Section: Introductionmentioning

confidence: 99%

UAV spraying on citrus crop: impact of tank-mix adjuvant on the contact angle and droplet distribution

Meng

Zhong

Liu

et al. 2022

PeerJ

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Adding tank-mix adjuvants into the spray mixture is a common practice to improve droplet distribution for field crops (e.g., rice, wheat, corn, etc.) when using Unmanned Aerial Vehicle (UAV) sprayers. However, the effectiveness of tank-mix adjuvant for UAV spraying in orchard crops is still an open problem, considering their special canopy structure and leaf features. This study aims to evaluate the effects of a typical tank-mix adjuvant concentrations (i.e., Nong Jian Fei (NJF)) on Contact Angle (CA) and droplet distribution in the citrus tree canopy. Three commonly used parameters, namely dynamic CA, droplet coverage, and Volume Median Diameter (VMD), are adopted for performance evaluation. The dynamic CAs on the adaxial surface of citrus leaves, for water-only and NJF-presence sprays, respectively, are measured with five concentration levels, where three replications are performed for each concentration. The sprays with 0.5‰ NJF are adopted in the field experiment for evaluating droplet distributions, where Water Sensitive Papers (WSPs) are used as collectors. Two multi-rotor UAVs (DJI T20 and T30) which consist of different sizes of pesticide tanks and rotor diameters are used as the spraying platforms. Both water-only and NJF-presence treatments are conducted for the two UAVs, respectively. The results of the CA experiment show that NJF addition can significantly reduce the CAs of the sprays. The sprays with 0.5‰ NJF obtain the lowest CA within the observing time, suggesting a better spread ability on solid surface (e.g., WSPs or/and leaves). With respect to the effects of NJF addition on individual UAVs, the field trial results indicate that NJF addition can remarkably increase both the droplet coverage and VMD at three canopy layers, except for T30 droplet coverage of the inside and bottom layers. Comparing the difference of droplet coverage between two UAVs, while significant difference is found in the same layer before NJF addition, there is no notable difference appearing in the outside and bottom layers after NJF addition. The difference of VMD in the same layer between two UAVs is not affected by NJF addition except for the bottom layer. These results imply that the differences of droplet coverage among different UAVs might be mitigated, thus the droplet distribution of some UAVs could be improved by adding a tank-mix adjuvant into the sprays. This hypothesis is verified by investigating the droplet penetration and the correlation coefficient (CC) of droplet coverage and VMD. After NJF addition, the total percentage of T20 droplet coverage in the bottom and inside layers is increased by 5%. For both UAVs, the CCs indicate that both droplet coverage and VMD increase at the same time in most cases after NJF addition. In conclusion, the addition of a tank-mix adjuvant with the ability to reduce CA of the sprays, can effectively improve droplet distribution using UAV spraying in the citrus canopy by increasing droplet coverage and VMD.

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“…on the adaxial surface of sourgrass leaves, the water CA values were approximately 152°, allowing classification as a superhydrophobic surface and thus reflecting a very difficult-to-wet surface (BARTHLOTT et al, 2017). The CA values of sourgrass with water were higher than those of other grasses, such as wheat and corn, which have CAs of 120 and 112°, respectively (MELo et al, 2015), and much higher than those obtained for some fabaceous species, which have CAs of 70-107° (SANToS et al, 2019), demonstrating the strong water repellency of the sourgrass foliar surface. In this case drops remain spherical shape on top of the wax crystalloids after deposition (KoCH et al, 2009), resulting in minimal contact between the drops and the leaf surface.…”

Section: Contact Angle (Ca)mentioning

confidence: 80%

Impact of glyphosate formulations and adjuvants: effects on leaf interaction, metabolism, and control of sourgrass

et al. 2022

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The addition of commercial formulations and adjuvants to a tank mix may result in differences in the wettability on the plant surface, foliar uptake and herbicide efficacy. Thus, the objectives of this study were to evaluate the influence of glyphosate formulations and tank-mixture adjuvants on the contact angle (CA), uptake, metabolism and sourgrass control and the damage to the cuticular microstructure of this species caused by herbicide solutions. For this purpose, assays were carried out in a completely randomized design, and treatments distributed in a 2x5+1 factorial scheme with five replications. Two glyphosate formulations isopropylamine salt (SL) and ammonium salt (WG) combined or not with the adjuvant methylated soybean oil (MSO), mineral oil (MO), ethoxylated alkyl ester (EAE) or polyoxyethylenealkylphenol ether (PAE); and one control (water) were evaluated. CA measurements of the droplets deposited on a sourgrass leaf surface and on the standard surface (parafilm) were obtained using a tensiometer. Herbicide uptake and shikimate accumulation were simultaneously determined by chromatography and spectrometry. The control effect was assessed by observing plant survival dry weight reductions. The glyphosate SL and WG formulations had similar effects on the variables analyzed. However, mixing the adjuvants EAE, MO or MSO with either formulation of herbicide led to greater wettability and more severe damage to the cuticular microstructure, favoring glyphosate uptake and shikimate accumulation. Despite evidence regarding the treatments containing oils/surfactants, the control effect on sourgrass was similar. The combination of glyphosate formulations with such adjuvants is potentially more effective and guarantees satisfactory sourgrass control.

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Does the Use of Adjuvants Alter Surface Tension and Contact Angle of Herbicide Spray Droplets on Leaves of Sida spp.?

Cited by 12 publications

References 15 publications

Evaluation of Some Adjuvants in Improving Foliar Fertilizers

Evaluation of Some Adjuvants in Improving Foliar Fertilizers

UAV spraying on citrus crop: impact of tank-mix adjuvant on the contact angle and droplet distribution

Impact of glyphosate formulations and adjuvants: effects on leaf interaction, metabolism, and control of sourgrass

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