Cultivation of vegetables

Major vegetable crops

Root crops

• Radish (Raphanus sativus, Brassicaceae) and carrot (Daucus carota, Apiaceae): cool-season crops sown directly by seed on ridges; not transplanted because roots get deformed. Carrot is rich in carotene (vitamin A). Forked or split roots result from hard soil, stones or uneven moisture.

Tuber and bulb crops

• Potato (Solanum tuberosum, Solanaceae): the tuber is a modified underground stem. Propagated by seed tubers; earthing up keeps tubers covered (exposed tubers turn green and develop solanine). Late blight (Phytophthora infestans) is the most serious disease. Stored in cold stores.
• Onion (Allium cepa, Amaryllidaceae/Alliaceae): bulb made of fleshy leaf bases. Raised from seed in a nursery and transplanted, or from sets. Bulb formation needs long days in rabi types. Pungency is due to sulphur compounds. Purple blotch is a common disease.

Cole crops (Brassica oleracea, Brassicaceae)

• Cauliflower: edible part is the curd (pre-floral fleshy apex). Disorders: whiptail (Mo deficiency), browning and hollow stem (boron deficiency), buttoning (small premature curds). Blanching (tying leaves over the curd) keeps it white.
• Cabbage: edible part is the head, a large terminal bud of tightly packed leaves. Diamondback moth is the main pest.

Fruit vegetables (Solanaceae)

• Tomato (Solanum lycopersicum): transplanted; staking supports plants. Red colour from lycopene. Disorders: blossom-end rot (calcium deficiency), fruit cracking. Fruit borer is a key pest.
• Brinjal (Solanum melongena): warm-season crop; shoot and fruit borer is the major pest; little leaf is a phytoplasma disease.

Leafy vegetable

• Spinach / palak (Spinacia oleracea or Beta vulgaris var. bengalensis): fast-growing, gives several cuttings, rich in iron.

Key points

• Radish and carrot are direct-sown, not transplanted.
• Potato tuber is a stem; late blight is its major disease.
• Cauliflower curd; cabbage head.
• Blossom-end rot of tomato = calcium deficiency.
• Brinjal shoot and fruit borer is a key pest.

Exam tips

• Know the edible part of each vegetable; this is a favourite question.
• Match each disorder with its nutrient.