Coriander (Coriandrum sativum) belongs to the family Apiaceae and is commonly known as Dhania. It is a bright green annual herb which is erect and hairless growing to about 40-60cm tall. In Kenya, coriander is grown in warm to cold regions for its attractive spicy leaves used to season food and salads, and its pungent seeds which are processed into mixed spices and curry powder.
VARIETIES IN KENYA
Coriander varieties grown in Kenya include;
- Cilantro– has flat toothed leaves, also known as spiny coriander.
- Seed coriander– this is grown for its seeds.
- Leaf Ciliantro-resembles parsley and has a strong and sharp smell.
- Vietnamese coriander– has narrow smooth-edged and darker leaves.
- Temperature– coriander requires a temperature range of 18- 25 degrees centigrade to germinate and grow into plants. It cannot withstand extreme temperatures, either too cold or hot.
- Soil– it thrives in a well-drained loam and sandy-loam soils with an optimal PH range of 6-8. This soil should be rich in organic matter.
- Sunlight- during germination, coriander needs sunlight for only few hours daily. However, as they begin producing leaves, the crop requires 5-6 hours of sunlight.
Propagation is by seeds.
- Choose a site that is flat and where crops belonging to the same family as coriander have not been cultivated for about 3-6 months.
- Spray land with CLAMPDOWN 200ml/20l in order to get rid of all types of weeds.
- Prepare a fine tilth. Mix soil with manure and DAP. In order to stimulate root development, improve nutrient uptake levels, improve the soil structure, among other benefits, incorporate manure (1 ton) and DAP 50kg (50kg) with 1 kg HUMIPOWER.
- Raise planting beds, about 1 m * 5-10m and make rows.
- Water the beds.
- Drench soil with a mixture of PYRAMID 100g + LOYALTY 10g + OPTIMIZER 20ml in 20l of water. This helps in getting free of soil pests and diseases as well as breaking seed dormancy and promoting uniform germination of the seedlings.
- Soak seeds in OPTIMIZER 20ml/1l for about 6-12 hours for better germination.
- Drill seeds in the rows, 2-4 cm deep, and 10cm apart.
- Cover seeds with a thin layer of soil
- Water seeds with a light water shower.
- Cover seeds with a thin layer of dry grass (mulch)
Seeds start germinating in about 1-2 weeks.
Once seedlings begin germinating, the mulch is removed
Pests and Disease Control
- Aphids– these are found on the underside of leaves and stems. Infestation causes the leaves to turn yellow and become distorted. They also secrete honeydew as they feed which encourages the growth of sooty mold on the plant. Spray crop with PENTAGON 10ml/20l or KINGCODE ELITE 10ml/20l. To get rid of the sooty mold, spray JAMBO CLEAN 100ml/20l
- Cutworms– these are brown chewing pests which are oftenly found in the soil near the plant root zone. They cut down young and tender stems, destroying the crop. Drench soil with Profile 60ml/20l or Pentagon 20ml/20L
- Armyworms– they feed on leaves creating circular to irregular holes, Spray Kingcode Elite 10ml/20l or Pentagon 10ml/20l
- Root knot nematodes– infestation leads to development of swellings/galls on roots. This causes reduction in plant vigour. The plant turns yellow and eventually wilts. Drench soil with Alonze 6ml/20l or mix fertilizer 50kg with Adventure 2kg whenever doing basal application of fertilizer, e.g. DAP, CAN etc.
- Damping off– seeds become soft and rot, failing to germinate while seedlings die after emerging from the soil. Water soaked lesions girdling the stems at the soil line can be seen. Drench soil with PYRAMID 100g/20l
- Powdery mildew– infection leads to development of whitish powdery growth on leaves, petioles and stems. As it progresses, leaves become chlorotic. Heavy infections can cause distortion of flowers, thus affecting production of seeds. Spray crop with RANSOM 15g/20l or CHARIOT 20ml/20l
- Soft rot– this is a bacterial disease. Infected plants have small water soaked lesions near the base of their petioles which become soft, sunken and brown as infection advances. Spray crop with GREENCOP 100g/20l
Nutrition & Nutritional Deficiencies
In order to ensure that coriander produces well, the plant should be supplied with enough amounts of nutrients.
The following foliar fertilizer are recommended;
- OPTIMIZER10ml/20l- this supplies both macro and micro elements which are very vital in the development of the plant. It is a super stress manager and helps to boost the immunity of the coriander.
- GOLDCHANCE RANGE 50g/20l- these supply nutrients to the crop with respect to its stage of growth and development, e.g. Goldchance Super Start, which is important at early growth stages, especially after germination.
- LAVENDER 20ml/20l- this is essential for early and vegetative growth stages of the crop.
Besides the foliar fertilizers, basal fertilizers like CAN (for top dressing) should also be applied.
These should be mixed with HUMIPOWER at the rate of 50kg: 1kg of Humipower.
- Nitrogen deficiency– plant becomes chlorotic. Older leaves may fall off. Stunted growth is evident. Correction; spray LAVENDER 20ml/20l or GOLDCHANCE SUPER GROWTH 50g/20l
- Phosphorous deficiency– leaves turn purplish and there’s production of poor quality flowers. There is a reduced plant vigor. Correction; spray DIMIPHITE 30ml/20l or LAVENDER 20ml/20l or GOLDCHANCE SUPER START 50g/20l
- Potassium deficiency– older leaves show interveinal chlorosis and marginal necrotic spots which progress inwards, even towards the younger leaves. As deficiency becomes severe, leaves may dry up. Correction; spray DIMIPHITE 30ml/20l or GOLDCHANCE SUPER FLOWERS & FRUITS 50g/20l
- Boron deficiency– this causes chlorosis of new leaf tips and die back of growing points. Correction; spray VITABOR GOLD 20ml/20l
It is of a great necessity to keep coriander garden weed free. This is because weeds compete with the crop for nutrients, space, water and light as well as harbouring pathogens.
When the crop has established, HOTLINE 50ml/20l is used to kill weeds which could have developed. This is a selective herbicide and therefore does not affect the performance of the crop whatsoever.
Note: Always mix INTEGRA 3ml/20l with pesticides whenever doing foliar sprays. It is a sticker, spreader and a penetrant and very important in improving the efficacy of the pesticides.
Maturity, Harvesting & Storage
Coriander plants are ready to be harvested after about 25-35days. However, different varieties have varied maturity days. All parts of coriander are edible but the fresh leaves and the dried seeds are the most preferred. The shiny green coloured leaves are plucked, or the entire plant pulled, unless one wants to harvest the seeds. Leaves begin turning feathery and yellow coloured flowers develop. This is followed by formation of seeds, which are harvested a week later.
Fresh harvested coriander can be dipped in in fresh water or refrigerated to prevent wilting.
The seeds are processed into useful forms, e.g. curry powder.