Cultivar selection and pest control techniques on organic white cabbage yield

Abstract

In Romania, as in many other countries, white cabbage is one of the most important vegetable crop species. The experiment was performed in the NE of the country during 2008-2009 in order to measure the impact of cultivar choice and pest control techniques on organic white cabbage [Brassica oleracea (L.) var. capitata f. alba (D.C.)]. This experiment included early, summer and autumn crops. The early crop compared four cultivars, the summer crop two cultivars, and the autumn crop three cultivars. The effect of various common organic pest control techniques was also measured. These techniques included: treatments with extract from neem (Azadirachta indica), potassium soap, Bacillus thuringiensis var. kurstaki toxins, application of a parasitic wasp (Trichogramma evanescens) and covering the crop with an agrotextile. Data were collected regarding the effect of cultivar selection and pest control technique on common local cabbage pests: cabbage flea beetle (Phyllotreta atra), cabbage fly (Delia brassicae), cabbage moth (Mamestra brassicae) and cabbage butterfly (Pieris brassicae). The highest yields for each respective growing season were obtained using the following combinations: 'Flavius' × agrotextile (early crop), 'Copenhagen Market' × agrotextile + 4 l·ha-1 azadirachtin + 12·104wasps/ha (summer crop) and 'Buzau' × 4 l·ha-1 azadirachtin (autumn crop).