Which biophysical and biochemical factors may contribute to higher resistance of cabbage (Brassica oleraceae L. var. capitata) to attack of the most important pests

Abstract

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).