Capsicum production is rising considerably in the country. This is attributed to many farmers adopting greenhouse farming and sustainable agribusiness. The crop is gaining popularity among farmers due to high returns and is an alternative to tomatoes.
To farmers they are good source of income as they have excellent prospects both for domestic and export market. It has been shown that an 8m by 15m greenhouse can earn a farmer over Ksh.300,000 in just over 6 months.
They are eaten raw in salads or cooked as a vegetable since they are a rich source of nutrients and vitamins. It is suitable for stuffing with fillings such as cheese, meat or rice and is also canned for sandwich making.
There are two types of capsicum varieties: Determinate (open field) and Indeterminate (greenhouse) varieties.
Greenhouse or indeterminate varieties grow with a single apical stem and few secondary branches reach relatively high heights of up to 2m and have high yield production through out their life time. They include: Commandant F1, Admiral F1, Nemalite F1, Green bell F1, Golden sun F1, Top 168 evergreen, Hecco F1, Red bell F1, Pasarella RZ F1, Ilanga RZ F1 and Grandisimo F1.
The open field or determinate varieties are the bushy and have a defined growth, height and period of flowering and fruit development. They include: Yolo wonder, Green bell F1 and California wonder.
Capsicum grow well at an altitude of 1600 m above sea level, medium rainfall of 800-120 mm per year, temperature of 20 -250C and soil pH of 5.5-6.8
Capsicum require slightly acidic soil with high organic matter, good moisture holding capacity, well drained and well aerated. It is important to carry out soil test analysis in order to establish nutrient status, pH, pests and diseases availability.
For open field, the land should be ploughed and harrowed to a fine tilth. Well decomposed manure should be incorporated with the soil.
Soil borne pests and diseases should be removed by fumigation, low pH(highly acidic soil) should be raised using lime and alkaline soil reduced by using gypsum.
One can buy established and high quality seedlings from propagators or can establish their own nursery to raise seedlings. In this case, it is recommended that they use nursery trays rather than raising on the ground. This is because nursery trays presents an ease of planting, reduces disease incidence, reduces wastage of seeds and makes transporting seedlings from one location to the next easy.
Seedlings are ready to be transplanted after 30-45 days and only healthy and strong seedlings are to be transplanted.
On the bed, holes should be dug with spacing from 60cm by 45cm or 60cm by 60cm.10g (equivalent of one tea spoon) of DAP fertilizer and 50g of starter fertilizer per hole should be mixed with soil. The seedling should be planted together with its ball of soil/coco peat.
The plant is highly sensitive to water deficiency especially in flowering and fruit development stages. It is recommended to water twice daily (morning and late afternoon) depending on the soil moisture level.
For a greenhouse of 8m by 15m, a 500 litre tank serving 350-400 plants per day on drip irrigation can be installed. However the drip irrigation pipes should be flushed on weekly basis to avoid clogging by algae and precipitates.
The plant is a heavy feeder of nutrients. After 3-4 weeks of transplanting top dressing by CAN fertilizer at a rate of 10g per plant should be applied for good vegetative growth. At the onset of flowering (4-5 weeks) a compound fertilizer like NPK at a rate of 10g per plant should be applied. During fruit development (5-9 weeks) NPK should also be applied at a rate of 10g per plant.
Caution should be taken as excess nitrogen can lead to poor fruit set, smaller fruits, hollow fruits, poor quality and excess vegetative growth.
This is achieved by training and trellising. Training is supporting the plant to grow vertically. It is done by wires running parallel to the beds supported by greenhouse bars and others held by four planks on the ends of the beds. Nylon strings are tied on the wires and trained on individual plants.
This should be done when the crop is at vegetative stage and before flowering and height nearing the knee height.
Old leaves should be removed as well as diseased and dead leaves to prevent spread of diseases and pests, to increase light penetration, increase air movement and reduce high relative humidity.
Once fruits are formed, the leaves below should be removed. The pruned materials should be removed and used as compost or burned if infested or infected.
Weeds are a nuisance to crops, they compete for sunlight, water and nutrients. They are also vectors for pests and diseases. The crop should be kept free of weeds. In order to avoid bruising the roots, hand weeding is recommended. Plastic mulches are effective in suppressing weed germination and growth.
Depending on variety and environmental factors, maturity is usually attained between 75-90 days after transplanting. Maturity stages include: mature green, yellow, red or orange stages.
The end-use is also a factor: For local market or processing purposes, harvesting is done after full maturity while for long distance shipping they are harvested at a less mature stage. Hand picking is the usual form of harvesting.
Post-harvest practices include: sorting to remove damaged, bruised, malformed or diseased fruits; cleaning to remove soil particles; grading by size, color or shape; packaging in corrugated cartons, wooden boxes and plastic crates; storage at 120°C and 86% relative humidity and transportation in cool condition.
The demand for capsicum is higher than the supply. Market opportunities for capsicum include: processors, exporters, institutions, whole sale markets, supermarket chains etc.
Pest And Diseases Affecting Capsicum
Capsicum like many horticultural crops is faced with the menace of pests and diseases. Though studies on management of this menace continues, researchers are making tremendous strides, however they have not yet achieved 100% control. It is advisable that regular scouting be administered on the crop. Common practices such as observing field hygiene, proper irrigation management, using tolerant/resistant varieties and crop rotation should be strictly implemented.