Kohlrabi

Short description of the species

Botanical name

Kohlrabi

Latin name

Brassica oleracea sk. Italica

Family

Brassicaceae

Plant height

flowering stem (2nd year): 0.4-0.6 m

Exposition

relatively undemanding (sun or semi-shadow)

Frost tolerance

cold-resistant

Keeping

medium

Water requirement

high

Soil requirement

medium-heavy, permeable, high humus content (requirement of direct organic fertilisation)

Soil pH

6.5 – 7.5

Edible part

direct consumption – side dish, soups

accessibility

Usage

direct consumption – side dish, soups; processing – freezing

Growing technology and harvest

Propagation

• generative – growing from seedlings

Spacing

• early cultivars = 0.25-0.30 x 0.25-0.30 m

• late cultivars = 0.40 x 0.30-0.40 m

Harvest

• manual selection according to bulb size

• early cultivars – putting with leaves on the market

• late cultivars – without leaves and storage for direct selling/storage

• delayed harvest date – bulb cracking (mainly early cultivars) or bulb woodening in early cultivars (supported by water deficit)

Important dates

• growing from seedlings + covering textile (early cultivars – protection to low temperature; late cultivars – protection against pests, mainly 2-3 weeks after planting)

• necessary regular irrigation (keeping of bulb quality)

Storage

• temperature = 0-2 °C

• relative air humidity = 90%

• late cultivars – long-term storage ability

Use

• direct consumption – side dish, soups

Diseases and pests

• damage in connection to un-suitable growing technology: head cracking and woodening, mainly in early cultivars (delayed harvest, irregular irrigation)

• the most dangerous disease: clubroot (Plasmodiophora brasssicae) – incorrect crop rotation

• virus diseases: virus mosaics

• bacterial diseases: wet rottiness (Erwinia sp., Pseudomonas sp.), black rottiness (Xanthomonas campestris pv. campestris)

• fungus diseases: falling of germinating plants (several species of microscopic funguses - Botrytis cinerea, Fusarium spp., Mycosphaerella brassicicola, Olpidium brassicae, Phytophtora spp., Pythium spp., Thanatephrous cucumeris, Verticillium spp. etc.), downy mildew (Hyaloperonospora parasitica), Alternaria leaf spottiness (Alternaria brassicicola, A. brassicae), cabbage ring spottiness (Mycosphaerella brassicicola), Phoma rottiness (Leptosphaeria maculans), Rhizoctonia rottiness (Thanatephorus cucumeris)

• pests: cabbage root fly (Delia radicum), cabbage aphid (Brevicoryne brassicae), flea-beetles (Phyllotreta spp.), white butterfly (Pieris brassicae, Pieris rape), cabbage moth (Mamestra brassicae), thrips (Thrips spp.), cabbage whitefly (Aleurodes proletella)