All year round Italian giant, Early snowball, Kibo giant, Rami F1, Patna early, Purple Cape, White Rock and Limelight.
Altitude: 1000-2000m above sea level.
Rainfall: At least 500mm per annum.
Soil: Fertile well drained with high moisture holding capacity, PH ranging from 6.0-6.5.
Temperature: 120-180C, 120C is more ideal for curd formation. Above180C leads to formation of poor quality curds. Above 280C curds suffer from disorders.
Land preparation should be done early prior to planting. Remove all the weeds from the field especially the perennials. Harrow the field to fine tilth.
Propagation and planting
Raise seedlings in the nursery. Harden the seedlings 7days before transplanting. Space the plants 45-60cm between the rows and 45cm between the plants for early maturing varieties and 60cm by 60cm for late maturing varieties. Seed rate range from 300-450g per hectare.
At planting phase apply 100kgN, 100kgP205 and 100-125kgK20 per hectare during planting. Top-dress using 20g CAN per plant when they attain 20cm height, followed by 40g CAN 3 weeks later.
Nutrient deficiency symptoms
The crop is highly sensitive to nutrient deficiencies; ensure all the desired crop nutrients in good time.
Nitrogen: Characterized by drafted growth, erect and then stems, young leaves are pale green and older leaves appear bright orange. Top-dress the crop at the right stage to avoid the deficiency.
Calcium: Characterized by hooking of young stems and severe collapse of tissues. Top-dress the crop at the right stage with CAN to supply calcium.
Manganese deficiency: Chlorate marbling of older leaves. One can apply chelated manganese.
Manganese toxicity/soil acidity complex: Curling and marginal necrosis in young leaves
Potassium: Leaves appear bluish green, intervenal chlorosis near margins, backward curling of lamina and scorching with forward curling of margins. Apply mono-potassium phosphate
Keep the field weed free during the production period. Carry out shallow cultivation to remove weeds and with their underground structures.
Irrigate when the conditions are dry to avoid tip burn and buttoning. Good drainage is important since the crop is highly sensitive to water logging.
Tie the leaves with rubber band or tape or twin e when the curd begins to show, this helps in covering the curd.
Diamond back moth: Spray suitable insecticide dynamic.
Cabbage aphid: Spray with suitable insecticide eg confidor.
Cut-worms: Dust transplanted seedlings lightly with suitable insecticide eg polytrin preferably in evening.
Black rot: Practice good field hygiene, crop rotation, plant resistant varieties, and plant certified seeds.
Dry rot/cancer/black leg: Practice good field hygiene, crop rotation, plant healthy seedlings, use copper based fungicides eg mancozeb.
Ring spot– Crop rotation, plant healthy seedlings, use copper based fungicides
Downy mildew: Practice good nursery hygiene, crop rotation, uses fungicides such as ridomil gold.
White rust: Crop rotation and field hygiene.
Bacteria soft rot: Crop rotation with legumes or cereals.
Cabbage yellowing disease: Practice crop rotation, rogue infected plants, plant resistant varieties.
Bruising: Results in rapid browning and decay.
Limp leaves/rubbery curd: Caused by dehydration and can be sign of senescence, ensure proper watering to keep the soil moist but avoid wet conditions.
Yellow head/over creamy: Caused by strong sunlight and temperatures. Harvest early in the morning before midday.
Black spots on head: Sign of fungal infections caused by stress from adverse weather conditions.
Ricey: The curds acquire a velvety appearance like boiled rice due to high temperatures.
Blindness: Failure to form heads due to injuries sustained from cold temperatures.
Hollow stem: Internal browning caused by boron deficiency.
Pinking: Caused by extreme irregular weather conditions.
Leaf/ formed heads: Caused by excessive vegetative growth due to excessive nitrogen application.
Cut heads when they attain diameter of 15cm and leaves are still vigorous and green. Ensure that the heads are fully developed, compact and clear white in color but before the curds begin to separate. Cut the heads leaving one of more set of leaves attached to protect the curds. Yield range from 20-25 tons per hectare.
Store the vegetable in low temperatures (40C) and high relative humidity ranging from 90-95%.