The application of pesticides and foliar nutrition is one of the most important practices in fruit and vegetable production throughout the world. In some cases it represents more than 50% of machinery used in fruit orchards in one season. Source: Jorge Riquelme S. and Patricio Abarca R. Informative Record N° 1 INIA.
It’s a general consensus of the main Cherry consultants and producers that “the next growing and production season begins in the post-harvest”.
It is also the time for a series of applications to maintain optimum physiological status in terms of nutrition, protection against diseases, specialty application use like sun protection and, besides, applications against difficult to control pests like phytophagous spider mites, San Jose scale and other pests present in the crop.
In each case you must always consistently achieve a high efficacy with the quantity of product necessary and at a sustainable cost, trying to generate minimum impact on the environment, to the applicators and consumers.
If we consider in summary (Table 1) of the development of foliar applications in the season, it can be detailed with different objectives, on different dates taking into account always staying inside an efficient parameter of application and control.
Table 1. Costs of standard foliar programs for cherry production in the central zone of Chile. Product costs and work day (WD) and machine days (MD), respectively. Source: Carlos Tapia, Raúl Osorio.
We must consider that this summary doesn’t contemplate specialty product applications like retention programs or fruit setting, protection against rain, color enhancers (mejoradores de color), etc. If you contemplate the use of dormancy breakers and homogenizers.
A much more complete program, inasmuch as is technically warranted, could generate an increase of around 40% of this cost, being able to have programs that exceed USD$ 3,500/ha just in the use of phytosanitary nutrition products.
Considering this, it is essential that in each case you locate and verify the real need to carry out the very specific high-cost programs. If that were the case (many orchards of high productive potential merit this), the most important thing is to carry out these applications with the highest efficiency possible, from the operational and technical point of view.
Maintenance of agricultural spray equipment
It is at this time, therefore, that it is necessary to develop a more rigorous inspection protocol for the machinery intended for applications of each of these solutions and carry out the preventive maintenance of all of the equipment available (sprayers and tractors). Once the maintenance is done we must count on precise calibration guidelines that are adequate for each situation of the orchards according to their topography, age of the orchard, conduction system, among others.
In prior articles we have covered the importance of each component of spray equipment and the annual preventive maintenance and the periodical control, besides the tractors intended to do this important job. At this time, we must associate a relative cost to the maintenance of each of them. Source: Informative bulletin Universidad de Catalunya. Agricultural mechanization unit.
Hydraulic pump: the maintenance of this hydraulic component must be carried out once a season and it must be inspected continuously, considering the working state of the pump, oil level and pressure of the this mechanism. In the annual maintenance check membranes or gaskets and pistons, according to the model and hydraulic system. The cost of the preventive maintenance of the hydraulic pump fluctuates between USD$ 350 – 400 yearly.
Cardan and cardan shaft: the maintenance of this security component must be done each season and its inspection must be permanent considering the state of the cardan shaft and that it maintain its anti-rotation elements (fastening chains). The greasing of this mobile component must be done daily. The replacement of the cardan shaft and the cardan axle is USD$ 200.
PTO (Power take off): the maintenance of this hydraulic component must be done once every season and its inspection must be continuous, considering the state of the pressure regulation valve, air distributor escape, aperture of sectors and the manometer that ideally has a reading scale of 1 : 1 in the isometric bar. The cost of a PTO and manometer are between USD $ 200 – 220.
Filters: the maintenance of cleanliness of these components must be done continuously and in every application. There are: filler neck filters, main or suction filters, nozzle filters and in-line filters. The cost of a set of filters for the filler neck, suction and nozzle fluctuates between USD $ 70 and 75.
Tank and its components: the maintenance and cleaning of this hydraulic component must be done continuously and after each application. Additionally it is recommended to carry out maintenance and continuous cleaning of the closing plug of the tanks. A component of the tank are the level hoses that must be visible, translucent and with a level visor. Another tank component is the lid(s), which must be in perfect conditions together with the pressure retainer valves; furthermore, they should close with ease. If it has a clean water deposit, it must be in perfect conditions with its lid and nozzle in order to meet its function as a security element. The cost of the tank lid varies between USD$ 35 and 40.
It is recommended to develop a cleaning rule of the tanks and neutral detergents and/or other specialized products. The cleaning must be done with the greatest regularity possible, ideally 5 when we use the products of difficult dissolution, and also mixing products. If it were possible due to cost and time it should be done in every “batch” of applications. The cost of the cleaning products fluctuates between USD$ 10 and 15 each time the cleaning is done. If we add 21 applications per year, we have a total cost of USD$ 210 – 305.
Conduits and hoses: The conduit hoses must be checked to see if they have leaks or perforations and, therefore, it is recommended to always maintain them conducted through the chassis of the equipment. The cleaning maintenance of these hydraulic components must be done continuously and after each application. It is recommended to develop a cleaning record with detergents and specific products for cleaning at least 3 times in the season and ideally 5, when we use the products that have difficult dissolution and also mix products. The cost of the conduit hose replacement is between USD$ 60 – 70.
Air unit: the maintenance of this component must be once every season to verify the good working order of the multiplier box in its positions of high, low and neutral. The blades must be verified to be in good working state and their angle adjustment in the fan unit. The protector screen of the air unit must be checked regularly, since it is a very important security element for the applicators. If the equipment has deflectors in air unit, it must be checked regularly to be in good working order with maintenance and its position. The cost of preventive maintenance of the air unit (oil for the multiplier box, greasing, possible repairs of protective screen) is between USD$ 65 – 70.
Nozzles: the maintenance of these components consists in regularly verifying their cleanliness, ideally before each application “batch”. To verify the good working order of the nozzles the flow per minute that it delivers must be checked and proven that it be that indicated by the manufacturer at a determined pressure (it is recommended to be checked at 10 bar). If the detected flow is higher than 10% of that indicated by the manufacturer at 10 bar, the nozzles with this defect must be replaced. The cost of an annual nozzle change, assuming a total of 16 nozzles, is between USD$ 70 and 80.
Agitation system: the verification of the good working order of this hydraulic component must be done regularly before each application “batch”. The maintenance cost of the agitation system may be between USD$ 30 – 40.
Diagnostics service, calibration and certification of agricultural spray equipment
There are numerous professionals who offer calibration services for equipment, agricultural sprayers that diagnose the components of the spray equipment in order to do repairs, improvement, cleaning and annual or periodical maintenance. The objective of each of these is to count on equipment that meets with applications with the greatest accuracy that are necessary for the crops. In this way it is possible to get effective and efficient results because of its use in the different solutions applied in the orchards.
The cost of the available services for this vary between USD$ 200 – 250.
In summary, the cost associated with the regular preventive maintenance of the spray equipment and good diagnostic and calibration services are presented in chart 2:
Chart 2. Maintenance costs of the sprayer equipment in USD$ dollars/equipment. Source: Carlos Tapia, Raúl Osorio.
Last of all, it is possible to point out that the sprayer equipment, with its respective tractor, efficiently attends a range of 25 to 30 ha; therefore, the cost per ha. of the maintenance item / ha. is between USD$/ha. 53 – 63. This cost only represents 1.7% of the annual program costs of cherry trees.
Conclusions: In order to develop effective and efficient application management plans one must count on equipment previously diagnosed in all its components, repair and replace the critical elements, do annual and periodic maintenance, regular cleaning and have highly trained personnel to develop the applications that will translate into the success of the crops to harvest, with the lowest environmental and personal impact.