New challenges about pesticide application equipment in Serbia: Usage of new nozzles types for better deposition and coverage.

Abstract

Unofficial results of inspections of pesticide application equipment stands out several parts of field crop sprayers. One of them are nozzles. Many producers (more then 90%) have bad nozzles. These elements are not in accordance with standard which means they have bigger flow rate and uneven horizontal distribution. Farmers don’t change anything on field crop sprayers from the time of buying. For them there is only one nozzle type for all kind of pesticide applications in different crops. As nozzles plays major roll in coverage and deposition, new problem was indentified due to worn nozzles. New problem in Serbia became weeds and their herbicide resistance.
If one field has to be sprayed up to nine times, it is obviously that there is a problem. Using appropriate herbicides in acceptable weather conditions don’t lead to weeds eradication. During many field tests and sprayers inspections, suspicions were confirmed. Main reason of presence of weeds resistance is exploitation factors and nozzles. It is better to say, many years of using non appropriate nozzles in combinations of unacceptable exploitation factors lead to poor and unacceptable coverage and total depositions on weeds. For Serbian farmers there is only one nozzle, T nozzle. Several years ago, for richer farmers air injector nozzle with single flat fan known as anti wind nozzle became a star. They are using this nozzle for everything as poor farmers using single flat fan T nozzle. Additionally, low pressure between 2 bar and 3 bars enlarge the effect and small amount of droplets doesn’t make good coverage especially in high speed as 10 to 15 km/h. In combinations of mentioned speed and pressure, nozzles deposition was between 23 to 37% of total amount of pesticide. Remaining amount was drifted to non target, soil or evaporated.
Due to that, Faculty of Agriculture in Novi Sad and Educational developing centre of PAE started with field testing of new brand nozzles, double flat fan low drift and air injector double flat fan nozzles. Research were conducted in open fields in many crops such as, corn, soya, sunflower, wheat by changing of nozzles, traveling speed and working pressure. At any time, suggested pesticide dosage was used. Combinations of aforementioned factors gave as results better coverage and bigger deposit on weeds. Due to higher pressure more droplets cause better coverage, less drift due to anti drift nozzles and air injector nozzles, resulting as bigger deposit up to 78%.