|
|
Efekt podpory výskytu přirozených predátorů škůdců na zdraví a vitalitu ovocných dřevin
Bernatová, Martina
Predators (both invertebrates and vertebrates) can have a positive or negative effect on the vitality and physiological processes of woody plants. However, the mutual effect and interaction of several different groups of predators and their influence by different habitat manipulations is still not well known. For this reason, the aim of my work was to find out how biological control, i.e. manipulation to support invertebrate predators, and, conversely, the exclusion of insectivorous predators from vertebrates (birds, bats), or a combination of these two manipulations, will affect the vitality (and health status) of fruit trees, specifically pear. The experiment took place in organic pear orchards in the Zlín and South Moravian Regions. In each orchard (n = 4), 16 trees were selected and divided into groups of 4 trees differing according to the type of manipulation: a) installation of cardboard bands to support invertebrate predators, b) construction with a net to exclude the access of birds and bats, c) combination of cardboard bands and structure with net, d) control tree. The experiment started in the autumn of 2021 with the instalation of cardboard bands and in the spring of 2022 with the instalation of structures with nets for exclusion of birds. During the season (from May to September 2022), samples were collected to determine and compare leaf biomass and herbivory, fruit biomass and damage, and the efficiency of photosynthesis and the content of chlorophyll in the leaves were also measured, as well as the leaf area index. Overall, the results showed a significant positive effect of the manipulations on pear vitality. The best vitality was recorded for trees with a combination of cardboard bands and exclusion of birds and bats. The results show the importance of supporting natural predators of pests (mainly spiders). On the contrary, it is evident that these interactions could be disturbed by insectivorous birds (bats), which have a significant predation effect on spiders and thus can have a cascading effect on the vitality of fruit trees.
|
guest ::
