Cauliflower Farming In Kenya, Planting Guide
Cauliflower is one of several vegetables in the species Brassica oleracea, in the family Brassicaceae. It is an annual plant that reproduces by seed. Typically, only the head (the white curd) is eaten. Cauliflower is low in fat, low in carbohydrates but high in dietary fiber, water, and vitamin C, possessing a high nutritional density.
Cauliflower Farming In Kenya
Cauliflower is one of the most important cool season vegetable crops grown throughout the country and relished by most of the people. Being a heavy feeder, cauliflower demands constant supply of large amount of nutrients and water for its luxuriant growth.
Cauliflower is mainly produced in Kiambu, which accounts for 89 per production mainly due to the county’s close proximity to Nairobi, the main market. Other producing counties include Taita Taveta and Kakamega.
The crop has numerous health benefits, including it helps to reduce cancer risk, fights inflammation, decreases the risk of heart diseases and brain disorders, improves digestion, is a good detoxifier, aids in weight loss, helps balance hormones and maintains good eye health.
It is rich in vitamins C and K and other minerals such as calcium, magnesium, phosphorous, potassium, zinc, sodium and iron.
Cauliflower Varieties in Kenya
- Cheddar AGM
- Flame Star Hybrid
- Graffiti AGM
- Kibo Giant
- Clapton
- Italian Giant
- Early Snowball
- Fioretto 60
Crop establishment
Cauliflower is propagated by seed, which are sown in the nursery bed and later transplanted after three to four weeks to rows 60-75cm apart and 45-60cm within the rows.
Wider spacing (75x60cm) is usually adopted for late-maturing cultivars and closer spacing (60x 45cm) for early-maturing cultivars.
Before transplanting, the nursery bed should be thoroughly watered three to four hours in advance to minimise damage during lifting of seedlings.
Preferable, remove seedlings separately, never pull as this may damage feeding roots.
Seedlings Propagation
Seedlings should be grown in a well-aerated medium, which has good water holding capacity and at a pH of around 6.5. Generally, peat, bark and vermiculite mixes are used. Medium problems typically include excessive tannins and low air filled porosity, which results in poor drainage and the buildup of green mould. The medium should be pre-enriched and the seedlings should be fertilized.
For optimum germination, the seedling trays should be placed in a germination chamber, at 20 °C with high relative humidity. The seedlings should be moved to the tunnel at the first sign of germination. The ideal temperature for seedling cultivation is 20 °C.
Seedling management is a critical factor in cauliflower production, as the following factors related to seedling production may result in physiological disorders:
- Incorrect sowing time.
- Cold temperatures, particularly below 7 °C.
- Cold grown seedlings.
- Over-fertilization of seedlings.
- Oversized seedlings at transplant.
- Temperature differences between the seedling nursery and the farm.
A precision planter is recommended to place single seedlings at a uniform depth.
Transplanting Cauliflower Seedlings
The following points should be kept in mind when transplanting cauliflower seedlings.
Firstly the seedlings must be transplanted and watered as soon as possible after delivery from the nursery. Ideally seedling should be transplanted 5 weeks after sowing. Secondly the seedlings should be placed vertically into the ground and not sideways. This is to avoid a condition known as “J rooting”. This condition results in a J shaped root system that ultimately decreases yield and head size. Thirdly the grower should ensure that seedlings are planted at the correct depth in a little hole that has been made in the ground prior to planting.
If the seedlings are forced into the ground without this planting hole, the root system will be damaged and the plant will experience stress resulting in poor yield. Once the seedling is placed inside the hole the area should be firmed so that sufficient contact is made between the seedling and the soil.
When planting seedlings a choice can be made between the square method and the staggered method of planting. The staggered method is more advantageous as there is less competition between plants compared to the square method where plants are directly opposite each other, thus maximizing competition.
Cauliflower Farming plant population
A general spacing of between 28 000 and 35 000 plants per hectare is recommended.
Botany
Cauliflower is a herbaceous annual for vegetable production and biennial for seed production. The term cauliflower is derived from two Latin words namely ‘Caulis’ meaning cabbage and ‘Floris’ meaning flower. The edible portion of cauliflower in the white curd like mass composed of a close aggregation of abortive flower developed on thick bunches of the inflorescence. This edible portion is called ‘Curd’ surrounded by leaves which are longer but narrower than those of cabbage.
Climatic Requirements for cauliflower farming in Kenya
Cauliflower is thermo-sensitive crop and requires cool moist climate. The early varieties may tolerate higher temperature and long days. The temperature requirement depends upon the maturity group. It may transform curding from 5ºC to nearly 28-30ºC.
The optimum temperature for young seedling is 23ºC. Early variety requires high temperature in short days. At relatively lower temperature, the curds of early varieties become riceyness, leafy,
loose and yellow resulting in low quality. At low temperature curds of late varieties remain under sized or small, showing some signs of bolting. In hot and dry weather, the curd becomes small and
hard. Thus it is very essential that early, main and late varieties are planted at proper time.
Soil and its requirement
It can be grown on a wide range of soil provided that they are rich in nutrients and have adequate soil moisture, possess a good drainage and also contain plenty of organic matter. Sandy loam soil
are preferred for early crops, while loam and clay loams for late crops. Cauliflower grows best on a neutral to slightly acid soils i.e. at PH 6.0 to 7.0. If the soil is below PH 5.5 liming at the rate of 5
to 10 quintal per ha should be done for successful raising of cauliflower.
Higher PH than 7.0 decrease the availability of boron. The soil must be thoroughly prepared to make it loose and friable, and retentive of moisture. Basic organic manures should be applied during the field preparation.
Fertiliser application
Cauliflower is a heavy feeder of nitrogen and potassium. Organic matter, phosphorous and potassium fertilisers should be applied before transplanting.
Top dressing using nitrogenous fertilisers is done four weeks after transplanting and three weeks thereafter. Rates are 5-10g/plant (185-370 kg/ha) of CAN and 200 kg/ha DSP.
Irrigation
Cauliflower has a shallow root system and, therefore, when the plants are growing, they will require constant availability of moisture.
Adequate moisture promotes production of large heads. Lack of adequate moisture may lead to tough, fibrous stalks and tip-burn of broccoli.
Weed control
It is shallow-rooted and care should be taken not to damage roots in the field as this would encourage entry of fungi and bacteria.
Clean weed control methods should be practised to avoid competition for water and nutrients. Mulching may also be carried out for weed control and moisture conservation.
In cauliflower, as the white curds appear, they should be protected from full sunlight which tends to turn them to creamy yellow, reducing market quality.
Early-maturing cultivars must be protected from sun injury by tying the long outside leaves loosely over the forming heads, a procedure referred to as blanching.
Late-maturing cultivars usually have enough foliage and are self-blanched by the in curving of the inner leaves.
Harvesting
It is harvested by hand as soon as the curds have attained market size but before they become discoloured, loose and ricey. Marketable heads should be cut with three to four whorls of leaves.
These should be trimmed long enough to leave a circle of petioles to protect the head.
PESTS AND DISEASES
The pests and diseases which attack cabbage, broccoli and kale are the same ones that attack cauliflower.
Pests
Aphids
They suck sap, causing curling of leaves and transmit viruses. Control: systemic insecticides; biological – lady bird beetle; cultural – intercropping, mulching using coloured mulch.
Diamond back moth
The caterpillar causes damage to cauliflower. It is the most important pest of brassicas worldwide. It feeds on leaf lamina from the underside causing windowing effect.
Control: Use of chemicals; biological – Bacillus thuringiensis; cultural – intercropping with strong smelling crops like garlic, parsley.
Cut worm
Larvae feed on stem base cutting it off. It is more serious at transplanting.
Control: Chemical – dusting around stem bases of transplants, using chemical baits (sugar in water + poison); cultural – unearth larvae and kill them.
Diseases
i) Black rot
Caused by Xanthomonas campestris pv campestris.
Characterised by yellow angular spots that progress inward from the leaf margin. Leaf veins become dark brown to black and heads may be deformed.
Control: Crop rotation with crops that are not related to broccoli. Use of clean seeds for planting, use of clean transplants, use of resistant varieties and practising good sanitation.
ii) Alternaria leaf spot
Caused by Alternaria brassicae. Symptoms include yellow, concentric spots on foliage. Infected broccoli seedlings may be stunted or killed.
Control: Crop rotation and use of clean seed.
iii) Downy mildew
Caused by Peronospora parasitica. The symptoms are yellow spots on the upper surface with bluish white fungal growth on the lower surface of leaves.
Control: Crop rotation, practise good sanitation, and weed management.
iv) Damping off
Caused by Rhizoctonia solani or Phytium spp
It’s a fungal disease and more problematic at the nursery stage. It causes a dark brown or black rot at stem base of seedlings resulting in death. It is common in overcrowded and or over-watered nurseries.
Control: Use of fungicides, avoid overcrowding and over watering of seedlings.
HEALTH BENEFITS
1. Rich in vitamins and minerals-They include vitamin k, thiamin, riboflavin, niacin, magnesium, phosphorous, fiber, vitamin B6, folate, pantothenic acid, potassium and manganese, all of which are critical important in the general body growth and functioning. Manganese is used in the body as a co factor for antioxidant enzyme, while potassium is important in intercellular electrolyte which helps counter hypertension effects of sodium,
2. Detoxification-Cauliflower helps body detoxification in a number of ways by activating detoxification enzymes. It also contains antioxidants that support detoxification.
3. Brain health-It contains choline which is key to brain development. In addition, it diminishes age related memory loss and the brains vulnerability to toxins during childhood as well as in adulthood.
4. Digestive health-It is a good source of dietary fiber for digestive health. This roughage helps in digestion, bowel movement and absorption of nutrients by the body.
5. Fighting cancer-Has sulforaphane that is known to kill cancer stern cells, thereby slowing tumor growth.
6. Anti-inflammatory benefits-As an excellent source of vitamin K this provides us with one of the hallmark anti-inflammatory nutrients. Vitamin K acts as a regulator of our inflammatory response.
7. Di-indolyn-methane (DIM) found in cauliflower is effective as an immune modulator, anti-bacterial and anti-viral agent, DIM is currently been found applicable in the treatment of recurring respiratory papillomatosis caused by the Human Papilloma Virus.
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