Effect of the Cultivar and Harvest Date of Kale (Brassica oleracea L. var. acephala) on Crop Yield and Plant Morphological Features

The experimental material consisted of three kale cultivars: Winterbor F₁, Redbor F₁ and Medium High Green Curly were obtained from three harvest dates. The experiment was conducted in a three-year cycle (2006-2008). Total yields ranged from 5.13 to 9.32 kg·m^-2, of which marketable yield constituted on average 51-72% and processing yield 27-34%. In the present experiment, 8.42 kg of total yield per 1m² was obtained from Winterbor F₁, 7.55 kg from Medium High Green Curly cv. and 6.71kg from Redbor F₁ as an average for all years and harvest dates. The highest total yield for all cultivars was from the second harvest date and ranged from 6.76 to 9.32 kg·m^-2. The dry matter yield of leaves with removed veins averaged between 0.28 and 0.50 kg per 1m² for all years and harvest dates.