Pesticide application technology in the 21st century

Journal of Environment Quality, 2001

A model for predicting the required spray drift buffer distance for a specified off target deposition level is described. The GDS model is based upon Gaussian diffusion and sedimentation of particles originating from an elevated instantaneous line source. Aircraft-induced near wake effects are ignored. Agreement between aircraft wake models FSCBG, AgDRIFT and the GDS model is reasonable for downwind distances greater than 50 m. The model has the advantage over Lagrangian models in that it is faster computationally and can readily provide real-time prediction in the cockpit over large distances (3 km). A sensitivity analysis has been performed on the model to elucidate the effects of the primary parameters on spray drift. The model has proved useful in the determination of spray drift buffer distances for regulatory purposes and in the development of appropriate spray drift management systems for aerial spraying. Further research work is required to refine the model to better account for air stability effects, collector type, evaporation and crop canopy.

2005

Accurate placement of pesticide droplets on to crop and weed surfaces is a key step in guaranteeing high quality food production. Pesticides impact on plant surfaces to give protective coverage for crops and destructive coverage for weeds. Coverage is determined by interactions between the size and density of spray droplets, humidity and turbulence of the air through which the droplets travel, the physical characteristics of the target plant leaves and the architecture of the plant canopy. There are however, increasing concerns over the effect of pesticides in the environment particularly when they move beyond a field boundary.

Biotherapy (Dordrecht, Netherlands), 1998

Atmospheric Environment, 2005

Air pollution due to pesticides is a persistent problem in modern agriculture, and little is known on the reversibility of its effects on the environment and health. Pesticides contaminate the atmosphere through various pathways. This paper discusses techniques for measuring and modelling pesticide emission, and the factors that affect drift processes during spray application. Chemical analyses allow the concentration of polluting agents in the air to be measured, and different methods have been developed for measuring diverse pesticide groups. Several air-sampling methods, which give different results depending on the amount of air collected, are reported. The use of various tracers, such as fluorescent dyes, is widely reported. Brilliant sulphoflavine is the best fluorescent dye due to its low degradation in sunlight. Various collector devices are used, the most common being 2 mm diameter polymer lines. Although the report indicates a good level of collection efficiency, a complete understanding of the adhesion phenomenon is necessary. The use of mathematical and computational models to determine pesticide transport simplifies test and field evaluation. However, a detailed characterization of the agricultural environment, with temporal and spatial variations, is still necessary. The most common models are limited to transport and deposition of pesticides in the liquid phase to areas adjacent to treated fields. Drifting spray is a complex problem in which equipment design and application parameters, spray physical properties and formulation, and meteorological conditions interact and influence pesticide loss. r

Journal of Pesticide Science, 2014

A series of spray experiments was conducted in order to determine deposition at different heights of the hedgerow and to estimate the effect of unsprayed buffer zones on spray deposition. Deposition varied highly with distance, absolute humidity, height, droplet size distribution and wind speed. Eighty-two percent of the observed variation could be accounted for by these factors. Droplet size distribution depended on nozzle type and working pressure, which confirms the potential of these factors for reducing spray drift. Unsprayed buffer zones reduced deposition in hedgerows, but the effect was more pronounced in the lower parts, where a reduction of 72% was obtained by introducing a 12 m buffer zone, whereas at 4 m height the reduction was less than 1%. Therefore, deposition at different heights of the hedgerow should be included in order to make risk assessments relevant for organisms exploiting different parts of the hedgerow.

This article summarizes findings of a survey of agricultural producers concerning their practices and attitudes regarding pesticide spray drift. The results reveal that just as the agricultural enterprises involved in the sample are diverse and complex, so too are the approaches that growers take to managing drift. Growers tend to use multiple strategies in approaching this problem and display flexibility in attempting to achieve drift reduction. At the same time, they are concerned about implications of drift reduction for farm profitability. Programs and regulations designed to reduce drift should be constructed in ways that allow growers to comply without bearing excessive costs.

Journal of Agricultural Science, 2018

Environment pollution related to pesticides has been confirmed by the scientific community for a long time, but the available information on the impact of this phenomenon on human health and the ecosystem are still insufficient. Contamination of the environment can occur through various pathways, ground deposits during the application of pesticides to crops are one of those pathways. The retention rate of sprayed droplets is an important factor both for the efficacy of the phytosanitary treatment and the quantities of lost pesticides on the ground. This paper presents an overview of factors that affect spray droplet behavior, involved process in sprayed drop fate and the mainly techniques for measuring pesticide deposits to the ground and plant retention. We present studies that have focused on pesticide retention and soil deposition during crop spraying in relation to sprayer equipment, used formulation and climatic factors. Plant retention and pesticide deposits during spray is a ...

Outlooks on Pest Management, 2007

Good pesticide stewardship requires understanding how pesticide applications work because howw ea pply pesticides influences their efficacyand their impact on the environment. This article describes howpesticidesa re applied to af ield at the most basic level -t hat of individual droplets from aspraycloud. Byusing aworked example, this article provides the basic tools needed for anyone to runt hrought hese calculations using their own products. Based on these calculations,weq uestion the validityof common approaches used to assess the relative value of different application techniques: equipment, adjuvants, or formulations.

2010 Pittsburgh, Pennsylvania, June 20 - June 23, 2010, 2010

Spray drift continues to be a major problem in applying agricultural pesticides. This paper summarizes the results of a 5 year study about drift from field crop sprayers using a unique integrated approach.

Precision Agriculture, 2009

This research was on the effect of the physicochemical properties of the spray liquid on pesticide spray drift. Ten pesticide spray liquids with various physicochemical properties were selected for study. Some of these spray liquids were also examined with the addition of a polymer drift-retardant. In the first part, laboratory tests were performed to measure surface tension, viscosity, evaporation rate and density of the spray liquids. Subsequently, drift experiments were performed in a wind tunnel. From the results it was found that the dynamic surface tension is a major drift-determining factor, and also that the addition of a polymer drift-retardant can reduce drift significantly by increasing the viscosity. Drift reduction was found to be less effective with spray liquids of emulsifiable and suspendable formulation types than with spray liquids of water-dispersible granules and powders.

Historical Materials from …, 1990

Engenharia Agrícola, 2013

The reduction of pesticide spraying drift is still one of the major challenges in Brazilian agriculture. The aim of this study was to evaluate the potential of different adjuvant products, such as surfactants, drift retardants, mineral oil and vegetable oil for reducing drift in agricultural spraying. The experiment consisted of quantifying drift of sprayings of 18 adjuvants dissolved in water under controlled conditions in a wind tunnel. Tests were performed in triplicates with spraying nozzles type Teejet XR8003 VK, pressure of 200kPa and medium drops. Solutions sprayed were marked with Brilliant Blue dye at 0.6% (m v -1 ). The drift was collected using polyethylene strips transversally fixed along the tunnel at different distances from the nozzle and different heights from the bottom part of the tunnel. Drift deposits were evaluated by spectrophotometry in order to quantify deposits. The adjuvants from chemical groups of mineral oil and drift retardant resulted in lower values of drift in comparison with surfactants and water. The results obtained in laboratory show that the selection of appropriate class and concentration of adjuvants can significantly decrease the risk of drift in agricultural spraying. However, the best results obtained in laboratory should be validated with pesticide under field conditions in the future.

2004

Interrelated factors affecting pesticide drift and deposition Sprayer Application Target Weather Operator Design Application rate Variety Wind speed Skill Droplet size Nozzle orientation Canopy structure Wind direction Attitude Fan size Forward speed Area Temperature Air volume Every row Humidity Air velocity and direction Alternate row

Vigyan Varta an International E-Magazine for Science Enthusiasts, 2024

The plant protection measure is one of the significant farm practices in the field of agriculture in terms of preventing crops from pest infestations and enhancing the crop produce while ensuring better quality yield as well as quantity. With the huge demand for crop production to meet global food security, farmers are applying excessive amounts of pesticides to keep the crop free from pest invasions. Generally, pesticides are specifically noxious to targeted pests, but the danger created when intensive applications of pesticides also affect other nontargeted species of the environment including humans, animals, soil microenvironment, and other living beings. However, the unintentional movement of pesticidal drift has a detrimental impact on humans and the environment remains a major concern in recent days. Therefore, we need to focus on pesticide application methods, routes of human exposure, and imposing threats to non-targeted species due to the pesticide application. The purpose of this article is to discuss the negative impact of

Environmental Conservation, 1980