Pe-tsai cabbage (Brassica pekinensis) is a variety of Chinese cabbage which, unlike other Chinese cabbage varieties, forms heads. It is very rich in vitamins and has a high nutritive value. Pe-tsai cabbage features very tender leaves which are used fresh for salads, as well as in preparing first and second courses.
The pe-tsai cabbage plants have a good vigor and a short vegetation period. The seedlings are transplanted at the age of 15–20 days. Maturity is 50–70 days from sowing, depending on the variety (hybrid) and growing conditions.
The best results are achieved with early spring cultivation for very early harvest and with autumn culture for October-November harvesting and subsequent storage.
Growing tips
The best preceding crops are annual legumes, cucurbits, winter cereals, and onion. Light-soil fields which readily warm up in spring are chosen for pe-tsai cultivation where early harvest is desirable. Healthy, uniform transplants are a prerequisite for early harvest. These should be 15–20 days old and have 3–4 well-developed leaves. The planting pattern is 50 õ 40–50 cm.
Pe-tsai cabbage is very sensitive to growing and temperature conditions, during both seedling production and open-field cultivation. Another feature of pe-tsai cabbage is its susceptibility to black rot and soft rot, especially where overgrown seedlings are used for transplanting and roots are injured during transplanting. Therefore, the method of choice for pe-tsai cabbage cultivation is using cassette or potted seedlings or by direct seeding in the open ground. It is also important to observe the crop sequence.
During cultivation of pe-tsai cabbage, bolting (flower stalk formation) may occur. Factors promoting bolting are as follows:
To obtain high yields, fertilizers are applied during the growing season at a rate of 300 g nitroammophoska, 250 g ammonium nitrate and 250 g potassium nitrate per 10 m2 (N 170, P2O5 50, K2O 160 kg of active substance per hectare). Nitroammophoska is applied with autumn soil cultivation; ammonium nitrate and potassium nitrate are given as supplementary fertilizing throughout the growing season. The fertilizer application rates are adjusted according to the nutrient status of the soil.
Systematic irrigation is a crucial factor in the cultivation cycle. During the growing season, no less than 5–8 irrigations are given to the crop with a water application rate of 350–400 l per 10 m2 (350–400 m3/ha) per irrigation. Combining drip irrigation with application of water-soluble fertilizers through the drip irrigation system (fertigation) is a highly efficient technique resulting in a more uniform moisture and fertilizer distribution in the root zone, more efficient water use, less soil compaction, and no soil crust formed. Readily soluble mineral fertilizers are given with each water application.
Pe-tsai cabbage heads are normally harvested before the top of the stem “opens up as a flower”, i.e. prior to the flower stalk formation: after the commencement of flower stalk formation, the eating and marketable qualities deteriorate sharply.
During the growing season, numerous pests such as blue fleas, cabbage aphid, cabbage butterfly and looper, cabbage moth, and thrips may attack the crop. Therefore, chemical control is an essential component of the pe-tsai cabbage production technology. In growing the pe-tsai variety of Chinese cabbage, particular attention should be given to pest control because blue fleas injure it more severely than the other brassicas.
Among the diseases attacking cabbage the most damaging are: black rot, soft rot, and Fusarium wilt. The pest and disease control measures are similar to those used in white cabbage. Of particular importance in carrying out the control measures is strict adherence to a proper crop rotation program and timely treatment of plants with chemicals.