Kvalitet aplikacije insekticida leđnim orošivačem u zasadu breskve / Quality of insecticide application in peach orchards using back sprayer

A significant factor in the efficient and economical application of pesticides, apart from the used plant protection product, is the appropriate application technique. The use of the back sprayers is limited to small areas, less than 0.2 ha, gardens or hobby users. The disadvantages of the use of the back sprayers are primarily the speed of the operator’s movement and the intensity of the air current generated by the radial fan. During 2017, efficacy of insecticide application by back sprayer in the suppression of the Oriental peach moth (Cydia molesta Busck) was evaluated in peach plantation (“Royal gem” variety) located in Mala Remeta. The experiment was conducted according to standard OEPP/EPPO methods. The type of experiment was a random block design in four repetitions. Insecticide was applied by foliar application, with “Solo 423 Port” spray gun and water consumption of 1000 l / ha. The aim of the study was to determine the quantity of preparations that reached five different locations on the peach tree. A 10% tracer solution which fluoresces under the light of a certain wave length was used. Evaluation of the application quality was conducted by placing Petri dishes of known area and volume on the tree, which were washed with deionized water after the application. The tracer concentration which indicates the deposit of the preparations, was read with the Shimadzu UV-Vis 1100 spectrophotometer at a wave length of 595 ± 2 nm or 630 ± 2 nm. On the basis of obtained results, the largest quantity of preparations (over 88%) reached the middle of the tree from the side from which the operator was passing. On the lateral sides, 26,2-32,4% of the working fluid came to the tree, and the least quantity reached the top, about 15%, because the path to the top was the longest. The problem with the use of back sprayers is actually the way of movement and application as well as the speed of the air current. The absence of purpose built sprayers creates a problem due to overwhelming drift, as well as the dripping of working fluid from the leaf, which greatly affects the efficiency of the application itself.