In a two-year field experiment, we studied the extent of damage caused by cabbage stink bugs (Eurydema spp.) on the frame leaves and the outer leaves of cabbage heads in relation to genotype color. We established that the extent of damage varied with genotype color. In both years of the experiment, the affinity of Eurydema spp. toward green genotypes was significantly greater on the first four assessment dates (from the third decade of May to the third decade of June), while on the remaining dates (from the third decade of July to the second decade of August) we did not establish any differences between the white and red genotypes. Cabbage stink bugs first appeared on white cabbage genotypes. The antioxidative potential conditioned by the content of anthocyanins was significantly higher on the red cabbage genotypes. Research shows that higher antioxidative potential is related to a lower extent of damage caused by Eurydema spp. The average value of antioxidative potential in the cabbage varieties was 0.58 mmol/100 g of the sample, while in the hybrids it was 0.47±0.01 mmol/100 g. We confirmed significant differences in values of antioxidative potential between red (0.68 mmol/100 g) and white (0.48 mmol/100 g) cabbage genotypes. Between mid-late (0.55 mmol/100 g) and mid-early (0.53 mmol/100 g) cab- bage genotypes we did not establish differences in antioxidative potential levels, while the average value of this parameter in the early genotypes (0.46 mmol/100 g) was significantly low. We established that the color of plants (cabbage) represents one of the successful factors of antixenosis and has the potential for reducing the damage caused by cabbage stink bugs in environmentally acceptable systems of cabbage production.

Raziskava o vplivu nekaterih biofizikalnih (vsebnost epikutikularnega voska) in biokemičnih (obarvanost listov, skupni polifenoli in antioksidacijski potencial) dejavnikov na odpornost zelja (Brassica oleracea L. var. capitata) proti poškodbam, ki jih povzročajo kapusovi bolhači (Phyllotreta spp.), kapusove stenice (Eurydema spp.) in tobakov resar (Thrips tabaci), je potekala v letu 2010 na Laboratorijskem polju Biotehniške fakultete v Ljubljani. V poljski poskus je bilo vključenih 20 genotipov zelja in sicer 9 zgodnjih, 5 srednje zgodnjih in 6 srednje poznih genotipov (glede na dolžino rastne dobe), 3 rdeči in 17 belih genotipov (glede na barvo listov) ter 14 hibridov in 6 sort (glede na poreklo). Statistična analiza je pokazala, da biofizikalna in biokemična sestava listov zelja najbolj vpliva na odpornost te vrtnine na napad kapusovih bolhačev. Ti namreč kažejo šibko preferenco do zgodnjega in rdečega zelja ter do hibridov, ki imajo visoko vsebnost epikutikularnega voska (r2 = –0,6137, r2 = –0,7603 in r2 = –0,6812). Prav tako smo pri kapusovih bolhačih ugotovili močno negativno korelacijo med antioksidacijskim potencialom in obsegom poškodb pri srednje poznem zelju (r2 = –0,7185), pri rdečem zelju (r2 = –0,7811) in pri sortah zelja (r2 = –0,7802).