Development of a direct injection system without time lag for application of plant protection products

Earlier systems for direct injection of plant protection products (PPP) did not satisfy the requirements of practical farming because of time lag between dosing of PPP and its application and because of cleaning problems. To offer solutions in this respect, a prototype field sprayer with direct injection for site-specific application was conceived, constructed and tested. This prototype has three separate nozzle lines, each with its own direct injection unit capable of preloading with individual spray mixture so that no time lag occurs in application. Calculated were the theoretically achievable working widths possible with the applied direct injection dosing pumps. Test stand measurements were carried out to determine dosing precision. The results show that good dosing precision is achieved in the different settings. Hereby, attention should be paid to the working range of the dosing pumps. The results show that practically-applicable systems for direct injection without time lag based on the developed prototype are possible offering the ability to apply PPP more precisely and site-specifically.