P. Marucco

A crop identification system (CIS) to optimise pesticide applications in orchards.

Summary In the ambit of the ISAFRUIT Project, a prototype sprayer able to adapt its spray and air distribution automatically, according to the characteristics of the target canopy, to the level of crop disease, or to environmental conditions, it is under development. In order to identify the characteristics of the target canopy, in terms of its size and density, a Crop Identification System (CIS), based on ultrasonic sensors, was studied and produced. The principles governing the functioning of the CIS system and the first experimental results obtained from spray deposition tests carried out in an apple orchard using a CIS-equipped prototype sprayer are described. The first results indicated that, by adapting the application rate to the characteristics of the target, the CIS enabled the amount of spray deposited on the leaves to be maximised with respect to lower and higher volume rates.

Environmentally Optimised Sprayer (EOS)—A software application for comprehensive assessment of environmental safety features of sprayers

Despite technological progress in pesticide application equipment, chemical crop protection continues to contribute to environmental pollution. Water is at risk of contamination with pesticides from point and diffuse sources and could be reduced to a great extent with a better sprayer design. The sprayer manufacturers and pesticide applicators need to take more responsibility for the prevention of water pollution and therefore they have to make environmentally responsible decisions at different stages, from designing to servicing sprayers. The objective of the presented work was to develop an interactive application that would support decisions made by sprayer manufacturers during the production process, and by pesticide applicators when selecting and operating the sprayers. The EOS (Environmentally Optimised Sprayer) is an application evaluating the risk mitigation potential of sprayers based on their technological features, within five risk areas, representing sources of pollution: (i) Inside Contamination; (ii) Outside Contamination; (iii) Filling; (iv) Spray Loss & Drift; (v) Remnants. The evaluator completes the EOS questionnaire by checking for the technical solutions identified in the evaluated sprayer and the result reflects the sprayer quality in terms of potential environmental risk mitigation. The EOS tool also proved its awareness raising facility and educative value when used during training activities and university courses.

Effect of sprayer settings on spray drift during pesticide application in poplar plantations (Populus spp.)

This study assessed spray drift generated by sprayer settings commonly used for pesticide application in poplar plantations (Populus spp.). Tests were conducted per the ISO 22866 methodology using a mounted air-assisted sprayer (Tifone VRP600) equipped with a swivel-cannon air conveyor (model Cannone 50S). Trials evaluated sprayer settings, combinations of nozzle types, airflow rates, and air direction in both adult and young poplar plantations. Overall, spray drift amounts registered downwind of poplar plantations were less than those obtained to derive reference drift curves during the EU Plant Protection Product registration process that used late-growth-stage fruit crops. In the adult poplar plantation, Venturi nozzles (TVI 8004 red) yielded the highest drift reductions compared to reference sprayer setting, especially at distances farthest from the sprayed area (86% between 40 and 47m). Highest total drift reductions were achieved when conventional nozzles (1.81mm ceramic disc-core) were combined with their spray direction modified for an inclined cannon spray unit. Alternatively, the young poplar plantation showed no drift reduction for distances farthest from the sprayed area, regardless of sprayer settings, which likely resulted from lower foliage density and widely-spaced rows. Yet, both Venturi nozzles combined with high fan flow rates and conventional nozzles combined with reduced fan flow rate showed total spray drift reductions of over 70% within the downwind sampling area. These experimental results represent the first set of data on spray drift amounts in poplar plantations, which is key for defining the reference curves and best practices to reduce spray drift in tall tree plantations.

Dust drift reduction effect of an air conveyor kit (dual pipe deflector) mounted on different maize pneumatic drills

BACKGROUND All maize drills produce a fine dust due to the seed coating abrasions that occur inside the seeding element. The air stream generated by the fan of pneumatic drills - necessary to create a depression in the sowing element of the machine and to guarantee correct seed deposition - can blow away the solid particles detached from the seeds. In order to reduce this phenomenon, a coated maize seeds company (Syngenta®) has set up an ad hoc dual-pipe deflector kit that easily fits different pneumatic drills (also old drills). In this study, the efficiency of this kit and the influence of different drill types on the kits performance in reducing environmental pollution were evaluated using three different pneumatic seed drill models. RESULTS The research showed that a dual-pipe deflector installed on a drill in standard configuration did not change the seeder performance, and by using this kit on pneumatic drills, irrespective of their design, it is possible to reduce by up to 69% the amount of dust drift in comparison with the conventional machine set-up. CONCLUSION The dual-pipe deflector, under the conditions employed in the present experiments, showed good performance with all types of maize pneumatic drill used. Irrespective of the seeder model on which it is mounted, it is able to obtain similar results, indicating its high operational versatility.

Potential external contamination of pneumatic seed drills during sowing of dressed maize seeds

BACKGROUND The use of pneumatic drills in maize cultivation causes dispersion in the atmosphere of some harmful substances normally used for dressing maize seeds. Some of the dust particles may be deposited on the machines body, becoming dangerous for the environment and for operators. The aim of the present study was to analyse the amount of dust deposited on the frame of drills during maize sowing operations. Tests were performed with different drills and in different operating conditions. RESULTS Data analysis showed that a significant amount (up to 30%) of the tracer can be deposited on the drill body. When wind was not present, higher quantities of tracer were collected and the forward speed did not influence significantly the tracer deposit on the seed drills. The use of different devices designed to prevent dust dispersion was able to limit up to 95% but was not able to eliminate the external contamination of the drill. CONCLUSION The particles present on drills could become a problem for the operator during the filling of the drill. Additionally, the environment can be contaminated if pesticide remains on the drill, generating point-source pollution when the drill is parked outside.

Spray Applications in Italian Apple Orchards: Target Coverage, Ground Losses and Drift

A three-year experimental study has been conducted in apple orchards of Southern Piedmont to assess the quality of spray deposition on the canopy, the incidence of ground losses and of drift effects according to the sprayer adjustments. A conventional air-assisted sprayer, fitted with an axial fan (900 mm in diameter) and hollow cone nozzles, has been used for the trials. Four different volume application rates (300, 500, 700 and 1000 l/ha) were compared, operating at 6.0 km/h forward speed and with an air flow rate equal to 30000 m3/h. To assess the coverage of the canopy, in three different growth stages of the crop, samples of leaves picked up from different parts of the plants treated with the test liquid (a solution of water and yellow dye Tartrazine E102) were analyzed, while ground losses were determined by means of Petri dishes disposed on the ground in the treated area. To evaluate the incidence of drift, samplers (filter papers) were fixed on poles above the top of vegetation in the middle of the treated area so to detect the amount of spray dispersed in the atmosphere and susceptible to drifting away from the orchard. Results pointed out that the application of reduced volumes (300-500 l/ha), calibrated according to the growth stage of the plants, allowed to obtain a better coverage of the target and to reduce ground losses, while increasing drift risks were registered when fine droplets were sprayed.

Developing strategies to reduce spray drift in pneumatic spraying in vineyards: Assessment of the parameters affecting droplet size in pneumatic spraying

Pneumatic sprayers are widely used in vineyards due to their very fine droplet size, which makes the drift risk to become an important problem to be considered. The aim of this study was to assess the effect of the spout diameter at the release point on the spray droplet size and uniformity achieved for different liquid flow rates (LFR) and air flow rates (AFR). A test bench was developed to simulate a real pneumatic sprayer under laboratory conditions, and it was empirically adjusted to match the air pressure conditions as closely as possible to real working conditions. Two positions of insertion of the liquid hose, the conventional position (CP) and an alternative position (AP), were tested for three LFRs, 1.00, 1.64, and 2.67Lmin-1, and four AFRs, 0.280, 0.312, 0.345, and 0.376m3s-1. The air speed decrease between the two insertion points of the liquid hose was measured. A Malvern SprayTec® instrument was used to measure the droplet size, and the D50, D10, and D90 parameter values were obtained. The relative SPAN factor (RSF) was also calculated. A model to predict variations in D50 was fitted using the aforementioned parameters. The results show that variations in the diameter of the spout significantly change the droplet size, producing a mean increase of 59.45% in D50 and similar increases in D10 and D90. The model developed to predict variations in D50 has a very high degree of accuracy (R2=0.945). The relative decrease in the air speed along the spout did not present significant differences for the different airflow rates tested. The results of the study show that the droplet size produced in pneumatic spraying can be modified easily by varying the air spout dimensions. This should be taken into account by manufacturers from a design point of view.

Assessing the influence of air speed and liquid flow rate on the droplet size and homogeneity in pneumatic spraying: Air speed and liquid flow rate influence on droplets in pneumatic spraying

BACKGROUND The efficacy of treatments in vineyards largely depends on the necessary balance between leaf coverage and spray drift and, therefore, knowledge about droplet size is of major importance, but scarce scientific information is available on pneumatic spraying, often adopted in this crop. The objective of this work was to obtain the relationships between the droplet size spectra characterization parameters and the main affecting factors in pneumatic nozzles. RESULTS Three liquid flow rates (LFR) and four air speeds (AS) were combined in laboratory conditions to assess their influence on the droplet size spectra (D10, D50 and D90), homogeneity (Relative Span Factor, RSF) and driftability (V100 ) in two different air shear nozzles (cannon-type and hand-type nozzles). The droplet size parameters were significantly affected by LFR and AS, and a model was fitted to predict droplet size in every spout type. The droplet V100 was also affected by both factors. The RSF was similar in both cases but did not follow regular trends. CONCLUSIONS The findings obtained can help vineyard farmers and technicians to effectively increase the efficiency and, therefore, the efficacy of the pesticide treatments reducing at the same time the spray drift risk by selecting appropriately the optimal values of the main operational parameters: LFR and AS.

The New EU Directives Requirements and the Innovation in Pesticide Application Techniques

The first reference to crop protection equipment dates back to the second half of the 19th century. From that time until the recent years, the evolution of sprayers had two objectives: The adaptation of machines to the needs of applying the chemicals available in the market and improving their working capacity. Only since the 1980s that the safety aspects related to the operator and to the environment have been taken into account as priority aspects. This line of evolution will be enforced in the near future especially in Europe due to the European Union (EU) Directive on Sustainable Use of Pesticides (2009/128/EC) and amendment of the EU Machinery Directive (2009/127/EC). Due to the globalisation process, developing countries are now also facing the need to promote the development of plant protection machinery in order to improve the quality of spray application and to reduce the environmental risks related to PPP dispersal. In this review paper, several examples of the use of information technologies to improve the performance of sprayers are reported as solutions for reducing water contamination of PPP due to point and diffuse sources. Finally, it is estimated that potential market improvement for sprayers and components due to the enforcement of the new EU Directive could be 1.3 billion euros for the next 7 years.