Support system for efficient dosage of orchard and vineyard spraying products

This paper establishes a system to support the dose evaluation part of the pesticide registration process so that growers can make more efficient use of different spraying products across a broad range of European orchards and vineyards. The system comprises: a dose adjustment model and a small database of standard target structures (i.e., regional exemplars where efficient and efficacious use of pesticide is obtained at the label dose rate). The model includes a generalised scaling group relationship between the parameters that describe: sprayer output, target row structure and spray volume deposit. The upper limit for dose adjustment is based on the environmental fate of pesticide and this is represented in the model by the ratio of maximum ground area dose rate to minimum efficacious deposit which is normalised for alignment with target structure measurements. The model is used to examine the leaf-wall-area dose rate recently proposed by the European agrochemical manufacturing industry for harmonising pesticide registration. Good agreement is demonstrated between published measurements and model predictions of ground area and leaf-wall-area dose rate variation at constant deposit for a wide range of target structures (i.e., English pome- and stone-fruit orchards and Italian vineyards). The results are used to establish standard target structures for spraying products with different uses. These standards are needed by regulators to: translate between the different methods of expressing dose rate and improve the accuracy of label dose recommendations. The standards are also needed by growers to enable: more accurate calibration of spraying equipment and prediction of the optimum adjustment of label dose rate for different orchards and vineyards. (C) 2011 Elsevier B.V. All rights reserved

The role of rain in dispersal of pathogen inoculum

The importance of rain in the dispersal of micro-organisms was first demon­ strated in the 1880s, in the classic studies of Pierre Miquel (Figure 1) on the microflora of the Pare Montsouris in Paris. Collected rainwater contained large numbers of fungal spores and bacteria and numbers of airborne spores and bacteria decreased while rain was falling (61). By contrast, numbers of airborne micro-organisms collected by the suction sampler frequently in­ creased during intervals between rain showersPeer reviewe

Spray drift from orchard sprayers AFRC Engineering contribution to 1988 field experiments

SIGLEAvailable from British Library Document Supply Centre- DSC:3604.9221(AFRC-IER-DN--1537) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

A comparative study of theoretical models of turbulence for the numerical prediction of boundary-layer flows

SIGLEAvailable from British Library Lending Division - LD:D55365/85 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Spray drift and bystander risk from fruit crop spraying

In the EU-FP7-BROWSE project (Bystanders, Residents, Operators and WorkerS Exposure models for plant protection products) spray drift data measured in the Netherlands and the UK for orchard spraying are combined to develop a probabilistic empirical model of bystander and resident exposure to spray drift. The model requires data relating to airborne spray to determine dermal and inhaled exposure, and relating to ground deposits, to determine indirect dermal exposure to contaminated ground. The available data can discriminate between full leaf (BBCH 74¿92), the intermediate periods (BBCH 61¿73 and 93¿0) and the dormant (BBCH 0¿60) period. For the BROWSE model, reference curves are defined for axial and cross-flow fan sprayers for ground deposit and airborne drift for 0¿1 m and 0¿2 m heights above ground as functions of distance downwind

Spray drift and bystander risk from fruit crop spraying

In the EU-FP7-BROWSE project (Bystanders, Residents, Operators and WorkerS Exposure models for plant protection products) spray drift data measured in the Netherlands and the UK for orchard spraying are combined to develop a probabilistic empirical model of bystander and resident exposure to spray drift. The model requires data relating to airborne spray to determine dermal and inhaled exposure, and relating to ground deposits, to determine indirect dermal exposure to contaminated ground. The available data can discriminate between full leaf (BBCH 74¿92), the intermediate periods (BBCH 61¿73 and 93¿0) and the dormant (BBCH 0¿60) period. For the BROWSE model, reference curves are defined for axial and cross-flow fan sprayers for ground deposit and airborne drift for 0¿1 m and 0¿2 m heights above ground as functions of distance downwind

Vertical dispersal of plant pathogens by splashing. Part II : experimental study of the relationship between raindrop size and the maximum splash height

This paper describes a simple experimental test of the theoretical relationship between raindrop diameter and maximum splash height proposed by Walklate (1989). This relationship contains two empirical parameters to model the characteristics of a splash target that limits upward movement of splash droplets. These parameters are estimated by fitting the proposed relationship to measurements of the maximum height of splashing from a variety of targets including leaves, straw and water films on horizontal plane surfaces. The experimental technique provides a simple and meaningful way to characterize the behaviour of splashing from plant material. This information can be applied to describe the upward movement of inoculum in crop canopies during rainfall.Peer reviewe