Cabbage is a biennial plant with green, red, purple, white, or pale green leaves that is mainly cultivated as an annual vegetable crop since the dense-leaved heads of the crops are consumable. It is a descendant of the wild cabbage and is closely related to cauliflower, broccoli, savoy cabbage, and Brussels sprouts.
Cabbage belongs to the family Brassicaceae and genus Brassica. The botanical name of cabbage is Brassica oleracea. The other members of the family include collard greens, broccoli, brussels sprouts, sprouting broccoli, and kohlrabi. All these variants are descendants of the wild cabbage, also known as field cabbage or colewort.
Cabbage has several cultivars groups, each containing several cultivars. Some of them include:
Spring Greens – The leaves of the plant are loose headed, commonly steamed or sliced.
Savoy – Savoys are detected by their characteristic curly or crimped leaves, tender texture, and mild flavor.
Green Cabbage – The leaves of the green cabbage are dark to light green, with slightly pointing towards the heads.
Red Cabbage – Red cabbages have red leaves, and they are mainly used for stewing or pickling.
Dutch Cabbage – The Dutch cabbage is also called white cabbage and is characterized by the pale, smooth green leaves.
In general, the weight of the cabbages ranges from 500 to 1000 grams. The most common forms of cabbage are the firm-headed, smooth-leaved green ones, whereas the purple ones or the savoy cabbages with crinkle leaves are the rarest. Cabbages can grow larger when they get long sunny days and are grown at higher altitudes. The cabbages are picked in the first year of their growth, but if they are intended to be grown for seeds, they are allowed to grow for the second year as well. However, they must be kept separated from other cole crops to prevent cross-pollination.
Cabbages are best grown in well-drained soil that receives direct sunlight. The soil requirements differ with the variant, and mostly heavier clay to light sand is preferred. However, all the variants prefer fertile ground with a pH value of the soil ranging between 6 and 6.8. For the proper head formation of the cabbage, adequate levels of nitrogen are required in the soil. In addition to the requirement of nitrogen for fertile growth, a sufficient amount of potassium and phosphorus is also required during the initial stages of outer leaves expansion.
A low temperature ranging from 4 to 240C is considered to be optimal for the growth of cabbage. However, extended periods of lower or higher temperatures might result in flowering or premature bolting. Such outcomes take place only when the plant is beyond its juvenile period, by a process called vernalization. The transition from the juvenile to the adult stage occurs when the diameter of the stem is about 6 mm. The plant is allowed to grow to a perfect size by the process of vernalization. A common practice in the United States is to plant cabbage at the start of the cold period and let it survive until the warm period. In this process, flowering is stopped until that time.
For cultivation, cabbage plants are generally grown in greenhouses or protected locations in the early growing seasons, before they are transferred outside into the direct Sun. However, many farmers prefer to plant the cabbage seeds directly into the soil. The soil temperature has to be around 20 to 300C. Cabbages become mature when they are solid and firm to touch. They are prone to nutrition deficiency and infection by bacteria and fungi. Moreover, it is beneficial to place cabbage seeds at least 30 to 61 cm apart since planting them close to each other results in lesser nutrition availability to each plant and therefore delayed growth.
Cabbage has high nutritional requirements and is, therefore, prone to nutrient deficiency. Some of the nutrients which can cause a problem to cabbage cultivation due to its deficiency are calcium, boron, potassium, and phosphorus. Problems caused by nutrition deficiency are necrotic spot development, internal tip burn, and pepper spot.
Cabbages are also prone to fungal diseases like wire stem, which causes dying or weak transplants. It can also suffer from Fusarium yellows that cause twisted and stunted plants with yellow leaves. Cabbages can also develop sunken areas on the stem and brown-grey spotted leaves, a condition called blackleg, due to fungal contamination by Leptosphaeria maculans. The fungi, Alternaria brassicae, and Alternaria brassicicola cause dark spots on leaves.
The most common bacterial disease on the cabbage plant is caused by Xanthomonas campestris, which results in black rot characterized by necrotic and chlorotic lesions at the leaf margins and wilting of the plant body. Clubroot disease, characterized by swollen roots resembling the shape of a club, is caused by Plasmodiophora brassicae. The cabbage plant also develops pale leaves with white olive or brownish mildew on the lower surface of the leaves, a condition known as Downy mildew, caused by the parasite Peronospora parasitica.
Pests that create problems in cabbage cultivation are cabbage maggots, thrips, root-knot nematodes, and caterpillars. Cabbages are grown at a distance from each other so that the bacteria, fungi, or pests are not transferred from one infected plant to any other healthy plant.
Cabbage is mainly used for culinary purposes. It is an integral part of any type of salad. It is considered a rich source of vitamin K and vitamin C. It also contains a moderate amount of folate and Vitamin B6. Cabbage is also a source of indole-3-carbinol; whole medicinal properties are now being investigated.
The cooling properties of the cabbage leaves have been used as a treatment for ulcers, breast abscesses, and trench foot. Cabbage juice and mashed cabbages are used in poultices for treating warts, removing boils, appendicitis, and pneumonia.
Excessive consumption leads to the formation of intestinal gas, which can cause flatulence and bloating. It might also create problems for patients suffering from hyperthyroidism.
Cabbage is a biennial crop that is grown in colder climates. It is a nutrient-demanding plant and is prone to infection by several bacteria, fungi, and other parasites. It has several other cultivars, all descending from the wild cabbage. Cabbage is mainly used as food and has many medicinal values. However, excessive consumption of cabbage might lead to bloating and flatulence resulting from the gas formation in the intestine.
1. Is cabbage an annual, biennial, or perennial crop?
Cabbage is a biennial crop. It can grow for two seasons. However, the cabbage is generally plucked at the end of the first year and either eaten or sold in the market. If the cabbage has to be kept for seed formation for the sowing of newer plants, the plant is grown for the next year as well. Till now, no cabbage plants are found to grow perennially.
2. What are the conditions required for cabbage cultivation?
Cabbage requires cooler climates for cultivation. It grows best at a temperature of 4 to 240C. It has high nutrition requirements like calcium, nitrogen, potassium, boron, and phosphorus, and the nutritional requirement varies at different stages of growth. Nutritional deficiency results in different diseases associated with cabbage growth. The soil pH has to be between 6 and 6.8. Cabbages are sown by keeping a sufficient distance between any two plants. This approach is taken to prevent nutrient deficiency for each plant and prevent the transfer of pathogens and pests from one infected plant to a healthy plant.
3. What are the nutritional values of cabbage?
Cabbage has several nutrient values. It is rich in carbohydrates, protein, and water. It has a negligible fat content. Cabbages are considered to be a rich source of vitamin C and Vitamin K. It also contains a moderate amount of Vitamin B6 and folate. Other nutritional contents of cabbage are being researched upon. The cabbage leaves have cooling properties. Due to its cooling properties, it is used for the treatment of trench foot in World War I by the British soldiers. Folk medicines describe its use in the treatment of colic, sore throat, rheumatism, hoarseness, and melancholy. Cabbages are also used in the treatment of warts, ulcers, pneumonia, and appendicitis. However, excessive consumption of cabbage leads to the development of intestinal gas and bloating. Moreover, two E. coli outbreak in Great Britain was linked to cabbage consumption.
4. What are the types of parasitic infections taking place in cabbage cultivation?
Cabbage is prone to infection by several parasites. Cabbages are often infected with fungi, bacteria, parasites, etc. To prevent the spread of infection, cabbages are sown with sufficient distance between them. Cabbages are also prone to pest infections like nematodes, maggots, and caterpillars. Cabbages show distinct phenotypic changes like necrotic and chlorotic leaves, club roots, and other disease symptoms because of infection due to these parasites.