Foraging activity of pollinators on apple tree

Jablana (Malus domestica Borkh) je ekonomsko pomembna sadna vrsta zmernega podnebja. Je samoneoplodna vrsta, ki za uspešno oprašitev potrebuje navzkrižno opraševanje, ki ga zagotavljajo različni opraševalci. Namen naše naloge je bil ugotoviti, kateri opraševalci so na jablani najpogostejši in tako ugotoviti pomen ohranjanja pestrosti opraševalcev. Opazovanje opraševalcev je potekalo v sezonah 2017 in 2018 v poskusnem sadovnjaku Kmetijskega inštituta na Brdu pri Lukovici. Najštevilčnejša opraševalka na jablani je bila kranjska čebela, poleg nje pa so bili pogosti tudi divji opraševalci, predvsem različne vrste samotarskih čebel in čmrljev ter muhe trepetavke. Dejavnost opraševalcev preko dneva se je razlikovala in spreminjala. Kranjska čebela, muhe trepetavke in samotarske čebele so prevladovale v osrednjem delu dneva. Čmrlji so bili dejavni cel dan, najbolj zjutraj, dopoldne in zvečer. Dejavnosti posameznih opraševalcev se je razlikovala tudi med leti. Na dejavnost opraševalcev je pomembno vplivala temperatura. Čmrlji so v enakem času obiskali dva- do štirikrat toliko cvetov kot kranjska čebela. Zaradi velike dinamike v dejavnosti opraševalcev in razlik v odzivu na vreme so pestra združbe opraševalcev ključne za zagotavljanje zanesljivega opraševanja jablane.Apple tree (Malus domestica Borkh) is one of the most economically important fruit trees in the moderate climate. It is known by its self-incompatibility, which relates to the necessity of cross pollination that is provided by a range of different pollinator species. The purpose of this master thesis was to define pollinators that are the most abundant on apple trees and to discover the importance of pollinator diversity. Our observations were done in 2017 and 2018 in apple orchard of Agricultural institute in Brdo pri Lukovica. The most abundant pollinator was honeybee which was followed by different wild pollinators like solitary bees, bumblebees and hoverflies. During the day, activity has differed greatly among the groups. Honeybees, hoverflies and solitary bees were the most abundant in the middle of the day. Bumblebees were active throughout the whole day, mostly in the morning, late morning and evening. Pollinators activity differed between the years. Pollinators activity was strongly influenced by temperature. Bumblebees visited twice to four times as many flowers as honeybees in the same time. Diverse pollinators communities are the key for providing reliable pollination of apple trees due to their large dynamics in pollinators activity and differences in response to weather conditions