SWEET POTATO PRODUCTION

SWEET POTATO (Ipomoea batatas)

Sweet Potato is a dicotyledonous plant belonging to the family Convulaceae. It is a perennial vine adaptable to different agro-ecological zones. It is widely grown on a small scale mainly in subsistence farming. The tubers are a rich source of the flavonoid anti-oxidants, vitamin A, dietary fibres and minerals.

Locally sweet potatoes are boiled or roasted and eaten either alone or with other foods such as milk, porridge, soups or grains. The sweet potato vines are a useful fodder crop, especially in the dry season.

Importance of Sweet potatoes in Kenya

·       Climate change is affecting amount and rainfall patterns, sweet potatoes is a more weather resilient crop

·       It is a low-input crop making it ideal for many smallholder households; crop rarely requires pesticides or fertilizers.

·       Production presents opportunity for farmers to improve their food security situation and income from the sales of surplus.

·       The ability of sweet potato to establish ground cover very fast enables suppression of weeds such as striga control of soil erosion and maintenance of soil fertility makes it an important crop for Kenya's farming systems.

Prospects of sweet potato in Kenya

• Sweet potato is now consumed by many Kenyans of all classes. More families and hotels are coming up with more creative recipes other than boiling the tubers. Sweet potatoes are regarded as a natural nutritious food due to the fact that they are grown without chemicals hence is perceived as healthier dietary choice. Consumption has increased in both local and 5 star hotels.

• In major producing areas marketing in most cases is through, some merchants from major towns e.g. Mombasa, Nairobi and Nakuru. They contract the farmers and purchase their tubers at wholesale prices on the farm

• Sweet potato is relatively cheap for households and serves as a good substitute for bread and cakes 

• The demand for sweet potatoes is increasing country wide with entrepreneurs venturing in sweet potato processing 

Other Opportunities in the Sweet Potatoes Enterprise include;

• Seed bulking  –to  produce and sell high quality vines/cuttings to other farmer

• Livestock feed – growing of sweet potatoes as fodder also manufacturing livestock feeds

• Industrial use – Starch is produced from sweet potatoes for industrial use (garment factories)

• Production of composite flours

Ecological Requirements

Altitude

Sweet potato grows at altitudes up to 2100m above sea level and is occasionally found as high as 2400m. The crop prefers lower and mild elevation zones.

Rainfall

Annual rainfall of 750-1000mm annually is best for production however some varieties are known to be drought tolerant. Although sweet potato can tolerate drought to some extent, yields drastically reduced when drought occurs during the first 6 weeks after planting and at root formation and development.

Temperature

Sweet potato is essentially a warm weather crop. Growth is best at temperature above 24°C. When temperatures fall below 10°C, growth is severely retarded.

Soils

Sweet potato grows best on sandy-loam soils and does poorly on clay soils. Good drainage is essential since the crop cannot withstand water logging. A soil pH of 5.6 - 6.6 is preferred. It is sensitive to alkaline or saline soils, and such soils should be avoided.

Where the water table is high, the crop is planted on mounds or on ridges. Soils with high bulk density or poor aeration tend to retard tuber formation and result in reduced yields.

Varieties

Both local and improved varieties are grown

·       Sweet potato varieties differ from one another in the colour of the tuber skin (usually white, brown yellow, reddish purple), colour of the tuber flesh (usually white or yellow), shape of the tuber, shape of the leaves, depth of rooting, time of maturity, resistance to disease and other vegetative characteristics.

·       Varieties whose flesh is yellow-orange coloured have high levels of carotenes used in synthesis of vitamin A. This is particularly important in parts of North Eastern, Coastal, Western and Nyanza regions where Vitamin A deficiency is prevalent.

Improved varieties that are grown in Kenya

SPK 013, SPK 004, Kemb 20, Kemb 23, Kemb10, KSP 20, KSP 11, Mugande Muibai, Ex-Diani, Mafuta, Japanese pumpkin and CIP Selection, 420009.

1.    Kemb 10 and SPK 004 are suitable for most areas of the country.

2.    KSP 20, KSP 11 and CIP, 420009 have shown good performance in dry areas.

3.    SPK 013 is recommended for the Western zone including the Lake Basin

4.    Kemb 23 and Ex-Diani are suitable for Central and Coastal lowlands.

5.    Mafuta is suitable for all sweet potato producing areas and is best for foliage production.

*N/B

·       The most traded variety of sweet potato in Kenya is the red skinned and yellow fleshed because of its high consumer demand.

·       High yielding vines (seed) can be obtained at KARI Regional Research Centres Country wide and from some farmers

Planning production

·       Ensure Climatic production requirement are met

·       Source for adequate clean planting material and variety that the market requires

·       Plan for marketing in advance

Land preparation

The field should be cleared and crop residues or grass (trash) removed. The field is then ploughed and harrowed. In the tropics sweet potato is grown on ridges, on mounds or flat seedbed. The growing of sweet potato on the flat seed bed should be is not recommended because the resulting yields are usually low.

The crop residues and other trash can be placed in between the ridges or mounds to facilitate moisture conservation and reduce soil erosion and can become additional source of nutrients when decomposed. It also suppresses weeds.

Early and thorough land preparation is necessary to create a deep loose seedbed ideal for expansion of tubers.

Ridges are recommended because of the follow­ing advantages:-

1.    Easy to make

2.    Higher yields and quality storage roots

3.    Mechanization is possible so commercialization of potato growing

4.    Soil moisture conservation

5.    Reduce soil erosion

6.    Inter-cropping sweet potato with other crops is possible

7.    Cultivation in mounds gives good yields and is extensively practised throughout the tropics.

Planting materials

Sweet potatoes can be propagated by use of storage root or vine cuttings.

a) Propagation by storage roots

When propagating by roots, the sets must be robust (healthy) and avoid using the rinds. The tubers should not be planted deep to avoid rotting. These can then be covered with small amounts of soil or no covering at all. This method of propagation results in very low yields and is not suitable for commercial production.

b) Propagation by vine cuttings

The use of vine cuttings is the recommended practice both for subsistence and commercial production. The vines are preferred to roots for planting because:-

• Vine cuttings are free from soil borne diseases.

• Use of vines leaves the entire tuber production for consumption or for selling compared to using roots for propagation that requires that some roots must be left for the next seasons plant­ing.

*N/B Yields are higher with vine cuttings than when roots are planted. Also better storage root in terms of shape and size are produced.

Preparation of planting materials

·       Select clean, healthy (free from virus and pests) vines 25-30cm. Longer vines result in wastage of planting material while shorter ones establish more slowly and give poorer yields.

·       Pieces from the stem apex are preferred to those from the middle and basal portions of the stem although, where planting material is in short supply, middle and basal vine cuttings may be used with little reduction in expected yields.

·       In drier areas with only one main rainy season the availability of planting material is a problem and farmers are advised to keep vines during dry season near water points on a nursery plot or under shade. Alternatively, leave some tuber in the soil over the dry season. When the rain comes the tubers sprout and the new vines are used for planting.

Planting methods on mound seedbed

There are three major planting methods used by farmers:

a) Cluster of vines in one spot on the mound. Usually 4-6 vines are planted.

b) 3-4 vines in single stand at equal distance from each other.

c) 2 vines per stand at equal distant from each other.

Planting method (b) is superior to planting method (a) and (c) in terms of storage root yield and quality.

The normal size of the mounds should have a base diameter of 30-45cm. The distance between the mounds should be 1 m apart (from the centre of mound to the next).

Planting methods on ridged seedbeds

There are two main planting methods on ridges which may be adopted.

i) Single row of sweet potato plants in the middle of the ridge at 30cm between plants within the rows. The distance between the centres of the ridges should be 1 m apart.

ii) Double rows of sweet potato plants on opposite sides of the ridges at 30 cm between plants within rows and 50-60cm between rows.

The sweet potato vine cuttings are planted at an angle with vine ends towards the centre of the ridge. One-half or two-thirds of the vine cuttings is placed beneath the soil.

Seed rate

The recommended number of cuttings per hectare is 27,000 cuttings/ ha or (11,000 cuttings per acre). Depth of planting is 4-6 cm deep.

Time of planting

Sweet potato can be planted at any time so long as there is sufficient moisture in the soil. However, it is best to plant sweet potato early in the rainy season so that it has the entire rainy season to grow. Where rainfall is biannual, two crops of sweet potato are possible.

Fertilizer Application

Normally sweet potato does not require fertilizers. Farm manure can also be applied to improve fertility and soil structure

*N/B in extremely poor soils, it may be necessary to apply a basal dose of compound fertilizer like 17: 17: 17 at 100kg/ha. However, extreme care should be taken not to apply N in excess which will enhance vegetative growth at the expense of storage root growth. 2 split applications are recommended, the first at planting and the second about 1 month after planting.

Weed control

Weeds are a problem in sweet potato only during the first two months of growth.

After this period, vigorous growth of the vines causes rapid and effective cover­age of the ground surface and smothers the weeds present. 2 hand weedings after planting are recommended. First weeding is done within 2 weeks after planting and the second weeding two weeks after the first one when earthing-up is being done.

Harvesting

i)            Young leaves can be harvested for vegetable use 2 months after planting.

ii)          Tuber harvesting:

·       The maturity period depends on the variety and the environmental conditions but generally range between 3-6 months after planting.

·       Yellowing and drying of leaves is mostly an indication of maturity. In most cases sweet potato is harvested as needed (piecemeal) and there is no fixed time for harvesting. One major disadvantage of piece meal harvesting is that many of the tubers are past their prime at the time when they are harvested.

·       Sometimes complete harvesting is done. Mature tubers are recognised by the sap exuded which does not darken easily or readily. Cracks in the soil indicate the location of the tubers. The crop yield depends on varieties, cultural practices such as timely planting, weeding and method of planting.

Yield

·       An average yield of 10-20 tons/ha can be obtained from growing any of the above mentioned varieties.

Storage

·       Whichever method of harvesting is employed, it is important that the tubers are free of surface wounds and bruises which may reduce their storage life.

·       Curing can also be done to promote healing of wounds inflicted during harvesting.

·       Tubers are cured by subjecting them to temperatures of 27-29.5^oC and relative humidity of 85-90% for 4-7 days and then stored at 13-16^oC.

·        In rural areas they can be stored in underground pits or on platforms, covered with soil.

Pests

Major pest is Sweet potato weevil

An adult fly feeds on leaves and stems causing thickening and cracking of the vines and feed on leaves. Larva bores into the storage roots producing a bitter substance

 Losses are estimated by retailer at 3 to 5%, due to weevils and rotting.

Control

i)    Early planting and prompt harvesting to avoid dry period.

iii)   Practice good field sanitation

iv)   Practice crop rotation.

v)    Use clean planting material.

Disease

Sweet potato virus causes dwarfing of the plants, yellowing of vines in young leaves and excessive branching. The disease is spread by aphids and white flies

Control

Use resistant or tolerant sweet potatoes varieties

ii) Use healthy, clean, virus free planting materials.

iii) Good field sanitation.

 iv) Control the white flies.

Challenges

·   Poor post harvesting handling, storage, and transportation from farm to market is the main challenges in sweet potato marketing

·   Bulkiness, perishability, high costs of marketing per unit sold.

·   In the Kenyan marketing system is not organized, hence farmers receive low price from the commodity through middle men

·   Processing opportunities are not exploited; Selling of fresh tubers gives low value for the commodity.

·   Use of low quality planting material lead to low yields and poor quality produce

Advice to growers

·       Need to plan marketing strategies by matching production with market demand to avoid losses

·       Value addition of sweet potatoes tuber for more profit by making products such as bread, cookies, crisps, chips, jam, juice, chapati and mandazi.

Pineapple Production

PINEAPPLES (Ananas comosus)

Pineapple is a herbaceous perennial plant in the family Bromeliaceae. The fruit has high sugar content and is rich in vitamins A and C. 

 Utilization

• Pineapples are eaten fresh as dessert and in salads or processed into juice, jam, dried fruits and preserves (crystallized and glace fruit)

• It is cooked in pies, cakes, puddings, or in sauces.

• The by-products of canning can be used as cattle feed, to produce pineapple wine or vinegar.

Marketing

The crop grown by the small scale farmers is usually sold fresh and unprocessed in open air markets, while the crop under large scale production is processed and sold either locally or exported. Pineapple market structure is inter-linked among farmers, retailers and wholesalers.

The fresh pineapples are sold to consumers in rural areas and urban centres by retailers while wholesalers sell mostly to urban markets.

Changing lifestyles and healthy eating trends has increase demand for pineapples, opening the market for smallholder farmers across the country.

Varieties

Pineapples varieties vary in size, shape, flesh colour, taste and transportability as shown below:

1. Smooth Cayenne- The fruits have a high sugar and acid content. It is grown commercially for both canning and the fresh market. It produces 2-3 suckers. The fruit weighs 2-6 Kg

1. Hilo -It produces no slips but numerous suckers. The fruit weighs from 1.1-1.5 kg. It has a very small crown.

1. Giant Kew- The variety bears a large fruit averaging 2.75 kg -4.5 kg. The core is large and its extraction results in too large a hole in canned slices.

1. Monte Lirio- Have smooth leaves with no terminal pine. The fruit is rounded, white-fleshed, with good   aroma and flavor.

1. Red Spanish - The fruit is fair for canning. It is highly resistant to fruit rot though subject to gummosis. The fruit   is   hard   when    mature and breaks off easily at the base during harvesting. Fruits stand handling and transport well. 

1. Queen- The plant is dwarf, compact, cold and disease resistant than 'Smooth Cayenne'. The plant matures early, it is low yielding and suckers freely hence requires thinning. It is sold fresh and keeps well. Fruits weigh 0.45 -1.13 kg

Ecological Requirements

Altitude

Pineapples grow from 0-1600 m above sea level. Altitude has an important effect on the flavour of the fruit; above 1800 m they become increasingly sour and acidic while below 1350m they are marshy and sweet. For canning, the recommended altitude should be below 1350m

Rainfall

Pineapple will produce fruit under annual precipitation of 650 - 3,800 mm depending on cultivar, location and atmospheric humidity (it should range between 70 and 80%). Ideal rainfall for pineapple production is about 1,100 mm. Reasonable yields can be obtained with as little as 750 mm of well-distributed annual rainfall or with supplementary irrigation

Temperature

A temperature range of 18 - 30°C is favourable and 25 °C is optimal. The plant can tolerate cool nights for short periods. Prolonged lower temperatures retards growth, delays maturity and causes the fruit to be more acid. Temperatures below 20°C can lead to chlorotic discolouring. The right combination of heat and moisture are important factors to consider for successful pineapple production.

Soils

The best soil for pineapple growing is a well-drained, sandy loam with a high content of organic matter and should be friable for a depth of at least 60 cm. Pineapples cannot stand water logging. The crop does well on soil of pH of 4.5-6.5.  Soils with old anthills have a higher pH, and are not suitable for the production of good pineapples as it reduces the yields. Avoid black cotton soil, low lying areas and common red loams that are likely to flood.

Planning Production

• Production quantity should be guided by the market demand

• Select variety according to use (Fresh or processing) and market demand

• Ensure site meets the production requirements

Land preparation

The land should be well prepared by deep ploughing to a depth of 45 cm before planting then harrowed to obtain fine tilth because the pineapple is shallow-rooted and easily damaged by post-planting cultivation.

Soil fumigation is recommended for land under continuous cultivation of pineapples without a fallow period. Use recommended fumigant e.g. Nemasol, Mocap

Propagation  

Pineapples are vegetative propagated by lateral shoots. The planting materials should be from newly harvested field.

3 types of planting material are used for vegetative propagation:

ü  Crowns are the leafy growth on top of the fruit. They take long to come into bearing (25-28 months) and rot easily, but the growth is uniform and less susceptible to premature fruiting.

ü  Slips are leafy shoot growth arising from the fruit stalks. They are graded according to size for growth uniformity. They ripen very unevenly and also take long to come into bearing (22-24 months).

ü  Suckers are leafy shoot growth from the base of the plant where the roots grow (stem auxial buds). They give the highest yield, and have long harvest duration. They are more difficult to plant. Suckers take 18-22 months to come into bearing. Suckers of 600g are too big and should not be used as they are too old and tend to flower early.

Rapid multiplication - If there is shortage of planting material, each type of planting material can be split vertically into two or four sections each with a bit of root section and planted into irrigated nurseries at very close spacing. They can then produce new plantlets in 3 - 4 months.

Control of infection in planting material

To avoid infection by dry-rot fungus, all the shoots should be stored in a shady place for wounds to heal and suberise quickly. No soil should remain on the shoots to prevent an infection by soil-borne fungus such as Phytophtora spp. and/or nematodes.

Immerse planting material in hot water at 50°C for 20 minutes to control mealy bugs, phytophtora and nematodes. After this treatment it is important to drip-dry the planting material to avoid fungus attack and deterioration. The planting materials are spread thinly on the ground to avoid overheating and rotting. Allow the chemical to dry on the seed.

Planting

• Planting is normally done at the beginning of the long rains. Strip off the basal leaves of the material just prior to planting to expose the adventitious roots facilitating good contact between the plant and the soil.

• Leave the planting material exposed to the soil, if the planting material arrives well in advance of the intended planting date. Stack the material upside down and cover with thin layer of grass.

• Slips and suckers may be planted to a depth of 10-15 cm without adverse effects.

Spacing

• Spacing depends on cropping pattern chosen.

• For monocropping where irrigation is available, a plant population of 70,000 to 100,000 plants/ha is possible. This can be achieved by planting double rows 40cm apart, 60 cm between the double rows, and 20 cm between plants. This can give a yield of 100 to 120 tons/ha plus about 40 tons/ha for the ratoon crop.

• Under rainfed conditions, spacing between double rows is increased to 60 cm apart and 90 cm between the double rows and 30 cm between plants. This spacing can yield about 75 tons/ha plus 30 tons/ha in the first ratoon.

• In intercropping, the same double rows can be used and interplanted with legumes and/or cereals. The intercropped area and the pineapple area can then switch location when pineapples are replanted. 

Mulching

ü  Use of black polythene 150 gauge is recommended to conserve soil heat, retain moisture, improve fumigation and control weeds. In hot areas, use of mulch may not be essential.

ü  Use of grass mulch should be avoided as it may reduce yields since it does not maintain the desired soil temperature.

Fertilizer and manure

Soil nutrient analysis should be done to determine levels of soil nutrients. Where soil nutrient are depleted, the following can be applied:

ü  300kg of DAP 10cm deep below the planting line in a furrow before mulching, or as a side dressing treatment at 11g/ plant when plants are about 2 months old. The fertilizer is placed at the base of the plant to avoid scorching.

ü  5 -10 tons/ha of manure can also be applied to the field 10cm deep below the planting line in a furrow before mulching and planting.

Application of fertilizer should only be done as per soil analysis, over use of fertilizer results in poor quality fruits.

Currently increased demand for organically grown pineapples.

Fertilizer is mainly used in large plantations due to soil degradation as a result of continous use. Fertilizer application is as shown below:

• 850 kg/ha of NPK and 750kg Sulphate of Ammonia (SA) after 6 months
• 750kg/ha of SA (Sulphate of Ammonia) is applied 3 months after first harvest and 720kg/ha of SA 3 months later. 
•  A general application of 100 -250 kg/ acre of rock phosphate should be added at the same time.

• Each ratoon crop will again need a new supply of nutrients and will benefit from compost as well as rock phosphate at the same rate.

Note

• Organic foliar feed is also beneficial. However, too much nitrogen will result in watery/ glassy fruit as well as in production of multiple crowns on fruits and too many slips
• Deficits in the potassium supply can be balanced out by the use of wood ash (combined with compost).
• No fertilizer should be applied after the first bud stage

Irrigation

• Irrigation is essential right after planting unless this is done during the rainy season. The field is watered thoroughly to initiate root establishment on the materials. After establishment, irrigation is only necessary when long dry periods occur.

• Overhead or drip irrigation is recommended while flood irrigation should be avoided.

• The excess water should be drained to avoid pathogens infestation and increase aeration.

Flower induction

• Pineapple flowering may be delayed or may be uneven, and it is highly desirable to attain uniform maturity and also to control the time of harvest in order to avoid overproduction in the peak periods.

• Synchronized flowering can be induced by smoke (due to ethylene produced). Ethylene and ethylene-releasing compounds (e.g. Calcium carbide) used in conventional production are very effective.

Weed control

• Spot spraying methods are used where there are weeds. Light hoes/Jembes are also used.

• Chemicals such as round-up are used to control couch grass.

• Use of black polythene is also recommended. 

Pests

Pineapple mealybug - Warm weather favours the build-up of mealy bugs.  Infestation cause discoloration of bronze to red or pink with margin bent abruptly backwards

-Control ants to give a chance to natural enemies to keep mealy bugs under control.

-Drench planting material in recommended insecticide Mocap, Nemacur

-Regular roguing (Uprooting) of affected plants should be done.

-Use clean planting material

Thrips -feed on the crown of fruits results in concentric ring patterns developing on crown leaves.

-Controlling weeds that habour thrips in the early stages.

Root-knot nematodes- cause distinct swellings (galls/knots) on the roots.

-Practice crop rotation

-Allow extended fallow

-Use recommended soil fumigants Nemacur, Mocap

Diseases

White leaf spot- The fungus causes white leaf spot, black rot, base or but rot and soft rot or water blisters.

-Choose sets with at least three nodes to increase the likelihood that the buds towards the centre will germinate before the fungus invades all the tissues.

-In disease prone areas, planting material should be treated in hot water (50°C for 20 minutes)

-Avoid extremely wet or dry soil conditions. Improve soil drainage and avoid planting during wet weather

-Do not plant freshly cut pineapples unless dried out.

- avoid wounds to tissue and remove infected plants. 

Pineapple wilt virus- Severely infected plants wilt, become stunted and produce small, undergrade and immature fruits.

-Use planting material from wilt-free areas. Control mealy bugs.

-Heat treatment of pineapple crowns in a large water bath at 50°C for 20 minutes

-Crop planted on virgin land or well-fertilized soils are more tolerant to wilt.

-Avoid adverse growing conditions which increase the susceptibility of plants to wilt.

-Younger plants stand a better chance of recovery

-Older plants are less susceptible than younger plants

-Slips and suckers are less susceptible than the mother plant on which they are borne

Yellow spot virus- Thrips are vectors of this virus. The fruit shows a blackened, dry cavity in the side of the fruit

-Avoid planting near host plants of the virus e.g. tobacco, egg plant.

-Control weeds in and around pineapple fields to reduce the thrips population.

-Destroy infected fruits showing early symptoms to prevent spread

7. Watery pineapples -The fruit becomes completely watery. The cause is mainly physiological and is associated with excessive late nitrogen application.

-Avoid applying nitrogenous fertilizer when the plants have started to bear fruit. 

Multiple crown- The smooth Cayenne normally has one crown on a fruit but occasionally more arise. High rainfall plus excessive Nitrogen application favour this condition

-To minimize occurrence, select suckers from single crowns only.

Harvesting

• It takes 18-24 months to get the first crop.100-120 tons/ha plus 40tons/ha for the ratoon crop can be achieved.

• A basal golden yellow coloration at the base is the sign of a ripe fruit.

• Fresh fruits destined for the local market are plucked when almost ripe.

• Fresh pineapples destined for export are harvested green-ripe (beginning to turn yellow-green at the base of the fruit). They are cut off with a sharp knife leaving a stem which is later trimmed to 3-4 cm. The cut should be horizontal to avoid bruising.

Post harvest management

• Fruits can be stored for up to 4 weeks at a temperature of about 7°C. Because of their low sugar-content, pineapples harvested too early are unpopular amongst consumers (unripe pineapples do not ripen after harvest).

• The colour of the skin is an important criterion in determining the ripeness of the fruit. Fruits destined for the European market are often classified according to the extent to which an orange-yellow colouring has spread up from the base of the fruit as follows:

• Ripeness-colour 1: Only the base is orange-yellow (For export).

• Ripeness-colour 2: The orange- yellow colour covers half of the fruit.

Care should be taken to prevent bruising of fruits. For canning the sugar/acid ratio (Brix) is measured and the fruit is graded according to sizes. 13 to 16° Brix is suitable for canning. This is only attainable when the fruits mature with plenty of sunshine.

Grading

The graded sizes are measured on the diameter of the fruit as follows:

• Grade I - 12.7 cm minimum diameter and 15.3 cm minimum length (about 3 ½ kg fruit)

• Grade II - 10.8 cm min diameter and 13.3 cm minimum length (2 ½ - 3 kg fruit)

• Grade III- 8.9 cm min diameter and 11.4 cm min length (1 ½ - 2 kg fruit)

Canneries accept only grade I and II.

Management of crop after harvesting

De suckering

Once the fruit has been harvested, remove all suckers from the mother plant and leave only one sucker for the ratoon crop. Leaving more suckers will reduce the size of the fruits.

Stripping

Removing slips from the mother plant. By doing this, planting materials are obtained and competition is reduced.

The rest of the slips and suckers can be used as additional planting material after sorting or can be chopped and used as mulch. The mother plant can also be left in the field as mulch.

Ratoon crop

The yields of ratoon crops are much lower than that of the planted crop; however one ratoon crop is economical. A second and third ratoon crop is possible under small scale conditions where the crop is interplanted with other crops, and fertilized well. Once this crop is harvested, all plants need to be dug up and the land prepared for rotational crops.

Crop rotation

• A rotation programme should be followed allowing 3-4 years before pineapples are grown on the same land again.

• Some crops usually included in rotation with pineapples are groundnuts, beans, rice and vegetables.

• Green manure plants such as cowpea can be grown and incorporated into the soil prior to planting pineapples. 

• Root knot nematode contributes to large crop losses, therefore to achieve some degree of control; land should be left fallow and free of weeds for at least 6 months.

Challenges in production

• Overproduction and oversupply in the market leads to low prices of fruits

• Poor quality pineapples (as farmers tend to harvest immature fruits) results in low prices.

• Disease and pest pose a serious challenge is not well managed

• It is too expensive for farmers to arrange their own transport to larger markets hence they sell through middle men and get low profits

• Pineapple fruits are bulky, hence this poses problems in transportation to distant markets. 

Advice to potential growers

It is important to produce high quality pineapples according to market specification in order to get premium prices. Farmers can also add value to pineapples by making products such as juice, jam, dried fruits and other preserves. In Kenya group marketing is encouraged to reduce marketing costs.