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Opportunities to reduce environmental contamination by pesticides through modified and novel spray application methods matched to crop canopy characteristics - LK0949

This project presents a unique opportunity to reduce environmental contamination by pesticides in the agricultural environment by tailoring spray applications to the pesticide target, the crop canopy characteristics at the time of spraying and the weather conditions. Development and evaluation of a novel spray delivery system such as the AeolianTM system alongside existing systems will allow the sprayer operator to modify pesticide applications to reduce environmental contamination whilst optimising pesticide use. An improved understanding of the fate of spray applications in a range of crop canopies with contrasting crop structures will improve decision making by the producer and sprayer operator potentially leading to a reduction in variable costs. The more efficient use of pesticides will have both economic benefits, in terms of improved yield and quality, as well as environmental benefits by reducing the impact on non-target organisms and ground water. This project is not intended to predict the reductions in dose rates which may be possible with improved deposition however, it will support future research activities aimed at minimising pesticide inputs.
This project is highly innovative in that it aims to exploit fluid flow dynamics, spray application technologies and measurements of crop canopy characteristics in order to significantly reduce environmental contamination by pesticides and optimise pesticide use. A new, innovative approach to spray delivery, as found in the AeolianTM system, potentially offers increased flexibility to modify droplet size and spray deposition. Remote measurements of crop canopy characteristics via boom mounted spectral, laser and sonic sensors allow for real-time monitoring of crop canopy geometry which has hitherto not been possible without laborious and time consuming destructive sampling. For the first time, these technologies applied to field scale crop protection challenges offer the opportunity to precisely tailor spray applications to the target and crop canopy
11 Objective(s)
The primary objective of this project is to test the hypothesis that environmental contamination (from drift and run-off) by pesticides can be reduced by modifying spray deposition patterns to a range of crop canopies by adjusting droplet size, velocity and the air flow delivery.
11.1 Scientific objective(s)

Objective 1:- Development and characterisation of the AeolianTM system.
The AeolianTM system will be developed to a full working prototype on a self propelled sprayer by Househams Sprayers Ltd. such that the system may be operated as a conventional hydraulic nozzle or AeolianTM system in the field. This will be supported by a similarly modified AeolianTM system for use in the wind tunnel experimental unit at SRI. Sprayer tests in the wind tunnel will be carried out to defined protocols in order to examine the effect of changes in air flow using the AeolianTM system on spray droplet size, drift and droplet velocity. The results will be compared with conventional and other air assisted sprayer systems from the published literature.

Objective 2:- Examination of spray deposition patterns at the field scale to define sprayer settings.
Spray deposition patterns on crop canopies and the ground will be investigated for each of the sprayer systems on ‘open’ and ‘closed’ potato, winter wheat and oilseed rape canopies to include variables such as water volume, droplet size and velocity, nozzle angle and air flow (depending on sprayer system). This will provide supporting data to identify a small number of optimal sprayer settings for each sprayer system for more extensive field experimentation involving in-field drift measurements, crop canopy measurements, detailed spray deposition studies and efficacy assessments.

Objective 3:- Measurement of spray drift in the presence of crop canopies at defined settings.
Using the sprayer settings defined in Objective 2, spray drift will be measured at a range of wind speeds in the field in the presence of contrasting crop canopies of commercial crops of winter wheat, potatoes and OSR using commercial sprayer systems.

Objective 4:- Examination of the interaction of spray droplets, velocity and air flow/movement with crop canopies.
Full scale field experiments will be carried out using conventional and air assisted sprayer systems with settings defined in Objective 2. A range of pesticide application targets treated with fungicides, insecticides and herbicides will be examined in crop canopies with contrasting architecture and including winter wheat, potatoes and oilseed rape (full details are given in Annex A). At each spray timing deposition measurements and canopy characteristics will be measured, where appropriate assessments of treatment efficacy will also be carried out.

Objective 5:- Correlation of droplet size, velocity and spray deposition with canopy geometry and future recommendations.
Correlations will be carried out to investigate the relationship between crop canopies and deposit distribution as well as physical characteristics of spray delivery from each system. Specific and generic recommendations will be made in relation to the future design and modification of each delivery system in relation to the crop species, target canopies, pesticide efficiency and where possible efficacy. Further recommendations on improvement in spray delivery design will also be made based on canopy findings and form part of the technology transfer process.
11.2 Interdependence of objectives
The objectives are only interdependent in that they require suitable spray equipment to be available at the timings required. A prototype working AeolianTM system already exists although this will not be fully committed to the project. A second, more highly developed system (Mark II) will be built at the start of this project. The technical drawings and specifications for this exist so no delay is anticipated. Bad weather conditions may delay some of the activities such as drift monitoring however flexibility has been built into the experimental programme in order to accommodate these eventualities.
11.3 Chances of achieving objectives
The consortium is very experienced in all aspects of sprayer technology, fluid dynamics and crop production and has planned the project to optimise the likelihood of achieving all the objectives. Although the AeolianTM system is an important part of the project valuable information and recommendations will also be gained from investigating the interaction of droplet size, velocity and air flow in relation to crop canopies with conventional systems.
11.4 Factors, specific to the project, which might delay achieving the objective(s)
In order to achieve the objectives it will be necessary to have good project management ensuring that protocols are in place and that equipment is well maintained, set up correctly, operated by trained sprayer operators and in the right place. To ensure this two sets of crop sensors, two AeolianTM systems (with hydraulic nozzles) (one full time the other 30% of the time) and an air assisted system (full time) will be available to the project team throughout the life of the project. At least 4 fully trained sprayer operators will be part of the project team.
Time-Scale and Cost
From: 2004

To: 2006

Cost: £315,722
Contractor / Funded Organisations
Househams Sprayers Ltd, Flow Research Evaluation, Velcourt Enterprise Ltd - LINK DUMMY ONLY, Syngenta Crop Protection UK Ltd, Velcourt Ltd, Agricultural Industries Confederation (VI), Silsoe Research Institute (BBSRC)
Arable Farming              
Crop Pests              
LINK Programme              
Pest and Weed Control              
Sustainable Farming and Food              
Fields of Study
Pesticide Safety