The PRECISPRAY project was initiated from the concept that "intelligent" precision spraying can enhance crop protection efficiency at any current breadth of biological knowledge, if agrochemicals will be targeted specifically to infestation levels and fitted to foliage volumes. The benefits of increased economical and environmental efficiency will be realized by reduced use of poisons, healthier crops, and healthier environment. This project is an attempt to apply advance technologies to horticulture practices and to agro-mechanization and revolutionize horticultural paradigms on the base of advance technology. Information Technology based orchard management becomes rapidly a mandatory requisite to fulfil food marketing chain traceability legislation, thus any advanced crop protection system will have to comply with.
The achievements of the PRECISPRAY project are described by the overall spraying efficiency and in detail by the success of it's three, parallel developed main components:
1. The orchard contour map guided precision sprayer, which delivers the spray materials dynamically following the tree canopy from an optimised distance for air velocity, and the spray quantity metered to the foliage volume facing the spraying arm.
- Spray deposit tests showed that spray reduction is 36% in early season and about 20% late season with fully developed foliage.
- Drift potential reduction potential, measured as deposits behind the tree row, was in the 35% - 50% range.
- Our biological efficiency tests showed that the sprayer was at least as effective as the traditional cross flow sprayer, with reduced spraying amounts.
2. Aerial photography derived Tree Position and Volume (TPV) orchard contour maps. These maps, delivered to the sprayer in the "StringLine" operative format, guide the sprayer arms to follow the tree contours.
- Lightweight digital aerial stereoscopic photography system was developed, including image handling and storage
- TPV map generation system was developed and the 'Stringline" files were delivered to the OM-GIS.
- The sprayer was test run in the orchards with manually measured stringlines, as the operators decided to use manually measured contours, to ensure the safety of the sprayer arms. That leaves the aerial stringline contours untested in actual operations. Overlapping the aerial contours on the original aerial photographs showed that the fit was quit good, but the caution was still justified.
3. The Orchard Management GIS (OM-GIS) is the management database, the user interface and the knowledge based crop protection Decision Support System (DSS). It is the depository, and retrieval system of the geographical, textual and numerical data of the farm management in general, and specifically the crop protection, including infestation and spraying history. The OM-GIS is interfaced by the "Stringline' format to the TPV system and to the Sprayer Guidance system.
- The OM-GIS was developed to an operational system, including all main modules, setup and installation programs.
- The pest management modules were beta-tested in real life situation and were proven operable.
- The TPV and sprayer interfaces were tested partly in full (TPV, and Sprayer Feedback) and partly in simulated (Spray Order) mode. The dataflow was seamless.
- The inference engine of the DSS is operative. The knowledge base has to be filled with beyond the initial with more content relating to the specific situations to be used.
In conclusion, the PRECISPRAY sprayer prototype demonstrated the expected increase in potential spray efficiency of a tree shape and volume following precision sprayer. Even without improvements in the aerial TPV system it may be used in a more restricted contour following mode, ensuring the safety of the cross arms, but still applying the correct spray amounts matching the tree structure.
The more widespread use of the sprayer will depend beyond of economics of equipment costs, which are expected to improve with the time, on the technological directions:
- Improvement of the accuracy of the aerial TPV system;
- Relaxing demands on the accuracy of the sprayer guidance, by relation to overall foliage volume instead of precise contours;
- Improvement in electronic distance measuring of fuzzy surfaces, which may switch the guidance system to directly measured or even real time contour following.
Regulatory requirements of agrochemical load reduction in the food chain and on the environment may change the economy of spraying, and bring into sooner introduction of precision sprayers, rational pest management, and accurate and automatic documentation, provided with the PRECISPRAY system.
The OM-GIS crop protection DSS system is usable independently for orchard management and crop protection with all types of sprayers.