The effect of the method and time of seedling production on red cabbage (Brassica oleracea L. ssp. oleracea convar. capitata (L) Alef. var. capitata L. f. rubra DC.) yield

Abstract

This study, conducted in the period 2006-2008, involved an evaluation of yield and commercially useful traits of red cabbage grown from seedlings produced from seeds sown at three different times (the second decade of April, the third decade of April, and the first decade of May). Seedlings were produced in multicell trays in an unheated greenhouse and in a nursery bed from seeds sown at the same time. The experiment included 6 red cabbage cultivars (‘Huzaro F₁’, ‘Kalibos’, ‘Langedijker Polana’, ‘Rodeo F₁’, ‘Roxy F₁’, ‘Zelox F₁’). After cabbage heads were harvested in the second decade of October (in each year), total and marketable yield as well as head weight and the head shape index were determined. Red cabbage yield was shown to be significantly dependent on the cultivar, time of sowing, and method of seedling production. Among the cultivars studied, the following proved to be the most productive, irrespective of the other experimental factors: ‘Zelox F₁’ (marketable yield averaged 398.11 kg×100 m^-2), ‘Roxy F₁’ (marketable yield averaged 368.82 kg×100 m^-2), and ‘Rodeo F₁’ (marketable yield averaged 331.59 kg×100 m^-2). The cultivar ‘Kalibos’ was characterized by the lowest marketable yield (on average 257.09 kg×100 m^-2). Delayed sowing (to produce seedlings) by 10 and 20 days, compared to the earliest sowing time, had a significant effect on the reduction in total and marketable yield. Irrespective of the time of sowing, the production of seedlings in multicell trays did not have a significant effect on higher head weight. But the influence of the cultivar was significant - heads of the highest weight were found in the yield of the cultivar ‘Zelox F₁’ (head weight was on average 1.71 kg). The head shape index was more than 1 and on average it did not exceed 1.35. The cultivar ‘Kalibos’ had the most elongated heads (with a conical shape), while cabbage heads in the cultivar ‘Langedijker Polana’ were closest to the spherical shape.