NWPPA – An Assessment of AGDISP™ Ground for Determining the Downwind Spray Deposition from Boom Sprayers
The movement of pesticide spray droplets outside of the application site during, or shortly after application can be reduced significantly by applying a range of drift reducing technologies and procedures. The recognition and assessment of these technologies during the registration of a pesticide product and at the time of application, provides the opportunity to increase the uptake and adoption of best practice spray management practices during agricultural and public health operations.
A series of field studies were undertaken to measure the deposition of spray droplets downwind of a boom sprayer fitted with a variety of hydraulic nozzles and under a range of meteorological conditions. Deposition rates of sprays for various application scenarios, were compared with predictions made with the most recent version of the AGDISP™ Ground model (version 8.28) provided by the USDA Forest Service. Model input values applicable to the tank mixes, droplet size spectra (based on wind tunnel testing), meteorological conditions, release height, application volume rate and canopy height used in the field trials were used.
A summary of the report is also available
The National Working Party on Pesticide Applications (NWPPA) commissioned John Kent from Charles Sturt University to undertake a “strategic assessment of current and potential revised national training framework(s) for pesticide application that would support the implementation of DRTs (as a mechanism to lower buffer distances), best management practice and improved product efficacy”.
Conducted in 2012, the review covered the main questions of what training and accreditation is needed within industry sectors, what is working well with current training, what can be improved, and options for how changes may be implemented.
To be formally recognised, all training must fall within the Australian Quality Training Framework and be based on the attainment of industry-endorsed Competency Units. Most training of pesticide users is conducted at level 3 (independent operator), with some at level 4 (supervisor) of the framework. Training must be delivered through registered training organisations.
Formal training and accreditation of agricultural chemical users commenced in the early 1990s. Over the years there has been very significant financial and in-kind support from research and development corporations, state and federal governments, industry corporations, grower organisations, universities, training providers, commercial industry and many others. For many of the training and accreditation programs, industry groups continue to have a major input through management boards and involvement. The impact has been outstanding with hundreds of thousands of participants and extensive practice change. However, it is evident that improvements can be made to enhance the impact and positive outcomes for all stakeholders.
The Australian Pesticides and Veterinary Medicines Authority (APVMA) implemented regulations on 1 March 2010 that require new pesticides to be assessed for the potential risk of spray drift. New label instructions can now contain statements that describe mandatory no-spray zones (buffer zones) in the downwind direction at the time of spray application. The labels of currently registered pesticides are also being reviewed to include comprehensive instructions for managing spray drift.
In October 2010, Plant Health Australia (PHA) was commissioned by the Grains Research and Development Corporation to provide independent support to stakeholders (through the National Working Party on Pesticides Applications (NWPPA)) regarding the review of pesticide spray drift risk assessments being conducted by the Australian Pesticides and Veterinary Medicines Authority (APVMA). Specifically, PHA was asked to:
(a) determine the information and model required to assist in the development of label application instructions to mitigate the need for default downwind buffer distances and
(b) accommodate and recognise the appropriate use of drift reduction technologies (DRTs) by users.
During November 2010, PHA consulted with a wide range of stakeholders with an interest in spray drift risk assessment and the management of pesticides, including the APVMA, researchers, funding agencies, Australian spray technology manufacturers, consultants, applicators and state government agricultural departments.