The goal of this work was to evaluate the potential of reduced application rates in apple trees as well as the potential of selective spray applications by using sensor-based tree detection techniques in Serbian fruit production. Their economical and biological effect was evaluated based on the quality and efficiency of the crop protection and technoeconomic analysis. Results showed that during suitable weather conditions and with properly adjusted sprayer settings, a reduced application rate of 381 L ha -1 gave same quality of crop protection as a medium application rate of 759 L ha -1 . A two-year efficiency trial on Venturia inaequalis and Podosphaera leucitricha infecting apple also showed that there was no significant difference in crop protection results for different types of orchard application techniques and application rates. The techno-economic analysis showed that selective application should be introduced in practice in areas > 3 ha given that the cost of their introduction pays off after 2-3 seasons. Every subsequent season would give a clear economic profit. Besides the economic benefits, selective application technique also has a significant positive ecological effect due to reduction of spray losses and the amount of plant protection products used.

Serbia is one of the leading producers and exporters of raspberry in the world, and considering the short shelf life of raspberry, the processing, storage, and transport are some of the main issues to be addressed. A comparative experiment was conducted in order to find the suitable process parameters for convective drying that may be considered as the alternatives to freeze‐drying, which is a widely used preservation method for raspberry even though it is a costly and energy‐consuming method. Twelve convective drying regimens were applied with a combination of three influencing factors: air temperature (60°C, 70°C, and 80°C), air rate (0.5 and 1.5 m·s−1), and stage of raspberry (fresh and frozen). The final product, a dried raspberry, was assessed for chemical, physical, and mechanical properties and rehydration capacity. Deep ranking analysis by power eigenvectors (DRAPE) and sum of ranking differences (SRD) were used to uncover the differences and similarities between the applied drying methods. SRD showed that convective drying of fresh raspberries proved to be more similar to freeze‐dried raspberries than convective drying of frozen ones. Fresh samples dried at 60 °C air temperature and 1.5 m·s−1 air flow proved to be the most similar to the reference freeze‐drying method. This convective regimen gives samples with the lowest color change, shrinkage, and shape deformation. With the mechanical and chemical properties of these samples being observed, statistical Duncan's test show that there is no significant difference (P < .05) in terms of hardness, shear force resistance, total phenolic, and total flavonoid preservation, compared with freeze‐dried samples. DRAPE gave similar results, but it added the variable importance in ranking as well, and total phenol reduction was defined as the most important variable. These results can help practitioners to develop cheaper and simpler drying methods that would replace the freeze‐drying but keep the same quality of the dried products.

No abstract

REZIME Aplikacija pesticida u voćarstvu je od izuzetne važnosti jer proizvod iz višegodišnjeg zasada korisnici konzumiraju direktno bez ikakvog sprovedenog postupka obrade. Osim što se aplikacija pesticide sprovodi radi kontrolisanja populacije štetočina, isto tako iga značajnu ulogu od zaostalih produkata stanovnika čiji je jabuka domaćin. Visoka norma tretiranja može imati ozbiljne posledice po efikasnost aplikacije isto kao i vetar koji utiče na drift al ii količina depozita zbog ostataka pesticide. U radu je prikazano ispitivanje orošivača pri hemijskom tretmanu zasada jabuke. Zabeležen je očigledan uticaj bočnog vetra koji je doprineo driftu a takođe i radni pritisak. Visok radni pritisak po pravilu utiče na formiranje sitnijih kapljica koje su sklone driftu. Na vertikalnu depoziciju pesticida dodatno utiče i vazdušna struja. Jačina vazdušne struje utiče na vertikalnu raspodelu radne tečnosti.

REZIME Za pravilnu i uspešnu primenu pesticida od posebnog je značaja izvršiti izbor odgovarajućih rasprskivača. Takođe, rad sa odgovarajućim pritiskom ima veliki uticaj na efikasnost tretiranja. Koliko će tretiranje biti uspešno direktno zavisi od poprečne distribucije pesticida. Dobra poprečna distribucija znači: ujednačen oblik i veličinu kapi, smanjenje odnošenja kapljica vetrom (drift), ujednačena količina sredstva i ravnomerna raspodela kapi, a sve u cilju manje potrošnje korišćenog pesticida i manjih troškova tretiranja. Rasprskivači se, uglavnom, izrađuju za definisan radni pritisak, koji može da obezbedi potrebnu dezintegraciju kapljica. Da bi kvalitet zaštite bio dobar i vek rasprskivača duži, pritisak tečnosti mora da se održava u tolerantnim granicama. Sa povećanjem pritiska veličina kapljica se smanjuje. Poprečna distribucija unutar celookupnog posmatranog područja mora biti jednaka, te se izražava pomoću koeficijenta varijacije koji ne sme biti veći od 10%. U području potpunog prekrivanja površine tečnošću, izbačena količina tečnosti ne sme da odstupa više od 10%. Navedeno je od posebnog značaja u tretiranju uljane repice, kao kultura sa velikom ali tankom biljnom masom u završnim fazama razvoja. Dobijeni razultati trebalo bi da prikažu koji od četiri testirana tipa rasprskivača daje najbolje rezultate rada pri promeni pritiska.

REZIMEHerbicidi pre nicanja i rani herbicidi nakon nicanja se široko koriste za kontrolu korove u kukuruzu u Evropu, gde nisu registrovani korovi tolerantni na glifosat. Među svim ovim herbicidima su velike razlike u stvarnom životu aktivnosti, rastvora u vodi, unosa lista i drugih karakteristika. Vremena primene specifičnih herbicida mora se redefinisati u zavisnosti od spektra korova, trenutne vlage u zemljištu i sposobnosti absorpcije herbicida. Stalno prisustvo vetra u intezitetu od 2 do 8 m/s posebno u područiju Banata otežavaju aplikaciju pesticida. Evidentan problem na parcelama u Banatu jeste veliko odstupanje u mikroreljefu. Usled toga, aplikacija pesticida je svake godine problematična jer se ne ostvaruje uniformna distribucija herbicida po površini.Korišćenjem odgovarajućih rasprskivača omogućava se bolja aplikacije pesticide. Bolja aplikacija podrazumeva povećanje količine depozita herbicida na ciljanu površiu što dovodi do povećanje efikasnosti apikacije. Adekvatna upotreba rasprskivača može povećati količinu depozita dvostruko što podrazumeva drastično veću afikasnost aplikacije.

No abstract

Timely and high-quality application of pesticides contributes to environmental protection, economical production and production of healthy food. The efficacy of pesticide application depends not only on the quality of pesticides but also the quality of the application. One of the factor that most influences the quality of applications, from the standpoint of mechanization, are nozzles. They working liquid applied on the surface the plant resulting in the same volume of pesticide is applied to the entire surface of the plants. To achieve this goal, nozzles must be performed uniform application of working liquid per unit area, or tractor sprayer working width. The variable factor in the application of pesticides may be nozzle and operating pressure. With increasing working pressure obtained smaller droplets. The paper presents test of three different nozzles. Each nozzle is characterized by a flat jet with an angle of 110° and a flow rate of 1.6 l•min −1 at a pressure of 3 bar. Differ from each other are by the way of disintegration of the jet. Exactly this characteristic causes that with pressure change coming to changes in the uniformity of nozzles transverse distribution. So the best distribution has nozzle with a flat jet. The coefficient of variation is between roughly from 4 to 6 % at the pressure application of 2 to 4 bar. Obtained mathematical model that describes changes in the coefficient of variation depending on pressure applications can be a good basis for easy harmonization parameters in the pesticide application.