Research on the impact of certain biophysical (epicuticular wax content) and biochemical (colour, total polyphenols and antioxidative potential) factors on the resistance of cabbage (Brassica oleracea L. var. capitata) against damage caused by flea beetles (Phyllotreta spp.), cabbage stink bugs (Eurydema spp.) and onion thrips (Thrips tabaci) was carried out in 2010 at the Experimental field of the Biotechnical Faculty. In a field trial the following 20 cabbage genotypes were included: 9 early, 5 mid-early, 6 mid-late (regarding the longevity of growing period), 3 red, 17 white (regarding the colour), 14 hybrids and 6 varieties (regarding genetic origin). Statistical analysis showed that the biophysical and biochemical composition of cabbage leaves has the greatest impact on resistance of this vegetable to flea beetles attack. Flea beetles showed only weak preference to early and red cabbage, and to the hybrids, which have a high epicuticular wax content (r2 = –0.6137, r2 = –0.7603, and r2 = –0.6812). It has also been found a strong negative relationship between the antioxidative potential and extent of damage in the mid-late cabbage (r2 = –0.7185), red cabbage (r2 = –0.7811) and cabbage varieties (r2 = –0.7802).
COBISS.SI-ID: 6704505
In this book chapter all activities that were performed at the Chair of Phytomedicine in the field of entomopathogenic nematodes (EN) are presented. In the beginning, the first laboratory trials from the time, when EN were still the exotic organisms, methods of soil sampling and detection of five EN species for indigenous in Slovenia, are described. Furthermore, the trials in greenhouses as well as in the open field, where satisfying efficacy of biological control agents mentioned against different insect pests are presented. On the basis of the results of the researches described in this chapter, EN are now already widely used among Slovenian producers of food.
COBISS.SI-ID: 6944889
The efficacy of Slovenian quartz sands admixed with stored wheat was examined against rice weevil (Sitophilus oryzae) in laboratory conditions. Five different samples of quartz sand of different age were tested: from location Raka-Ravno (with admixture and clean), location Moravče (with admixture and clean) and commercially available cleaned quartz sand from Puconci locality (Plantella), each at six concentrations: 100, 300, 500, 900, 1200 and 1500 ppm. The amount of SiO2 in all sand samples is high and varied from 91,52 to 99,24 %. For each dose rate, the treated wheat grains were placed at four temperatures (20, 25, 30 and 35 °C) and at 55 % relative humidity level. Dead adults were counted after 7, 14 and 21 d of exposure. After 21 d counts all the exposed adults were removed and progeny production on treated grains was estimated after 60 d. All samples showed some insecticidal effect on adults of rice weevil. Commercial quartz sand formulation showed the most promising results with approx. 90% mortality of rice weevil adults at 1500 ppm and at 30°C. At these conditions the progeny production was the lowest (7 adults per treatment) in experiment.
COBISS.SI-ID: 6921849