CASHEWNUT- KOROSHO
KOROSHO-Cashew nut. (Anacardium
occidentale ) Mkorosho / mkanju (Swahili)
Order/Family: Sapindales: Anacardiaceae
Pests and Diseases:
Anthracnose Cashew stem girdler Cashew weevil Coconut bug Helopeltis bugs Mealybugs Powdery mildew Thrips Aphids
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Cashew trees are grown along the coastal plains of Kenya and
Tanzania. Cashews are evergreen trees with deep taproots, originating from the
northern part of South America. The Portuguese introduced cashew to Mozambique
in the 16th century where it flourished forming extensive forests; eventually
it also became dispersed in East Africa. Cashew is grown along the coastal
plains of Kenya and Tanzania
Uses
The kernels or nuts have a high nutritional as well as
commercial value and are used for human consumption either raw or roasted. The
cashew nut apple is rich in Vitamin C (about 5 times higher than the orange)
and is used for the production of juice, wines, spirits, jam, pickles and
chutneys.
The liquid of the shell is used for brake linings, heat proof and waterproof paints and protective varnishes. Cashew nut wood is of poor quality but can be used as firewood if mixed with other types of wood.
The liquid of the shell is used for brake linings, heat proof and waterproof paints and protective varnishes. Cashew nut wood is of poor quality but can be used as firewood if mixed with other types of wood.
Climatic
conditions, soil and water management
Cashew trees are usually grown at altitudes of between 0-500
m above sea level (asl), but can grow up to 1000 m asl. They can be very
drought resistant provided their roots can penetrate deeply into the soil and
draw water from the subsoil. For mature trees 500 mm of rainfall per year is
adequate, but seedlings should be watered until properly established. If
rainfall is below 900 mm per year plant at the widest spacing indicated. Cashew
nut trees tolerate a wide range of soils provided they are deep and well
drained. They can grow quite well on infertile soils but do not do well on
coral outcrops at the coast.
Varieties
(contact your extension officer)
Planting
material
Select seeds from healthy, high
yielding trees. Before planting, sort out seeds by the water density method as
follows:
- Place the seeds in a bucket of sea water (100g salt per 5 litres of water) and select the seeds that sink for planting. Those that float have poor germination and growth potential.
- Sun dry seeds for planting for several weeks to prevent mould and rotting.
- Do not plant seeds that are more than one year old
Land
preparation and planting
Clean the field and dig holes
30cmx30cmx40cm deep and refill with topsoil mixed with 1 bucket of well-rotted
manure or compost. Due to their extensive root system cashew nut trees compete
for water and nutrients and therefore should be well spaced. Their canopies
should not touch one another since this interferes with production of flowers
and hence fruit setting.
Recommended spacing in good rainfall areas is 12mx 6m, giving 139 trees per ha. In low rainfall areas spacing of 12mx12 m (69 trees/ha) is recommended to give the trees a better chance for survival.
Only the healthiest trees are worthwhile keeping for long growing periods.
Planting methods include:
Recommended spacing in good rainfall areas is 12mx 6m, giving 139 trees per ha. In low rainfall areas spacing of 12mx12 m (69 trees/ha) is recommended to give the trees a better chance for survival.
Only the healthiest trees are worthwhile keeping for long growing periods.
Planting methods include:
- Direct planting of seeds: This method has the advantage that less labour is needed but there is higher risk of death during dry season and also a higher risk of early diseases. Plant 3 seeds per hole covered by 6-8 cm of soil
- Raising seedlings in polybags in the nursery: This method has the advantages that it is easier to water the seedlings properly, which is particularly important in the dry season, and that is possible to select the strongest and healthiest plants for transplanting. Disadvantages are that more labour is required and it is a bit more expensive. Seedlings in polybags should be transplanted 6 weeks after sowing in order to avoid damage to the taproot
Intercropping
This can be done before the canopies close. Most annual
crops can be used apart from cotton and sweet potatoes, which are host plants
for Helopeltis bugs, major pests of cashew. Do not interplant young trees with
pasture because of the high competition for water during the dry season.
Husbandry
No fertilizer is required, but well rotted manure at
planting is beneficial. Keep the area around the tree (1 ½ times the size of
the canopy) should be kept clean of weeds for the first 2 years to avoid
competition. If planted on a slope the tree should have a U-shaped mound of
soil below it to collect rainwater for improved growth. Seeds germinate within
2-4 weeks.
Thin after 3-4 months leaving only the strongest plant at each site. Protect seedlings from monkeys, rodents and bucks by placing wire cages or thorns around the seedlings. Support plants with a stick and trim off side shoots up to 60-90 cm from ground level. When trees are mature, prune dead wood or any borer damaged or inter growing branches to give the canopy air and light.
Thin after 3-4 months leaving only the strongest plant at each site. Protect seedlings from monkeys, rodents and bucks by placing wire cages or thorns around the seedlings. Support plants with a stick and trim off side shoots up to 60-90 cm from ground level. When trees are mature, prune dead wood or any borer damaged or inter growing branches to give the canopy air and light.
Harvesting
Trees normally bear fruit when they are 2 ½ - 3 years old.
They reach maturity after 9-10 years and may have an economic life span of
30-40 years if well cared for. Harvesting starts at the beginning of October
and continues till the end of December. Pick only the nuts that have dropped
down and remove the attached apple by a twisting action. Pick on a weekly basis
in the dry season and daily in wet weather to avoid fruit rotting or insect
damage. Store only dry nuts. Average yield is about 6 kg/tree but with good
husbandry 12 kg/tree can be obtained.
Sun dried raw nuts for one to six
days to reduce moisture content to 9% or less for safe storage and to mature
the seed through the infra red and violet rays of the sun. Correctly dried nuts
are pinkish in colour and produce a rattling sound when shaken. No mark can be
made on a dry nut with a thumbnail. Dry raw nuts can be stored under dry
conditions for at least two years without losing their flavour, but they are
generally processed within one year of harvesting.
The decortication of cashew nuts is hampered by the liquid contained in the cashew nut shell. This liquid is a viscous, oily liquid, pale yellow to dark brown in colour with a bitter taste and caustic properties; it causes blisters on human skin unless precautions are taken, and it will spoil kernels on contact. In traditional artisanal cashew processing the nuts are put in an open pan over an open fire and stirred continuously to avoid scorching until they start burning, then they are thrown on sand to extinguish the fire and to remove the remaining humidity on the outer skin.
In industrial processing the nuts are graded in different size classes and rehumidified at about 16% moisture by spreading water over them for about two days to make the kernel elastic and to fill the cells of the shell with water. Then, they are roasted in a hot oil bath heated to 192°C for about 90 seconds depending on the size of the nuts. Through the roasting process, the cells of the shell break and about 25 % of the shell liquid flows into the bath. The remaining liquid on the outer shell is removed with sawdust.
Both the artisanal and the industrial methods make the shell brittle so that they can be broken easily.
Another method to avoid contamination of the kernel with the shell liquid is to deep-freeze the nuts and split the shells while frozen.
There are different methods for manual cashew shelling. The simplest consist of placing the prepared nuts on a stone using a hardwood stick to crack the shell. A semi-mechanised process uses a pair of knives shaped in the contour of half a nut. The knife system is also used in industrial plants. In another industrial processing method centrifuges are used to crack the shells; shells and kernels are then separated in an air stream, heated shells are lighter and blow away.
After shelling the kernels have to be dried to about 6% moisture content, thereafter the testa can be peeled off easily. Kernels are then graded, rehumidified to 8% and packed in airtight containers filled with carbon dioxide (CO2) and sealed. The CO2 inhibits infestation by insects and is slowly absorbed by the nuts thus producing a vacuum that prevents shaking and breaking of the nuts during transportation.
Cashew apple processing:
Apples are steamed under pressure or cooked in a 2% salt solution to remove the astringency. Addition of gelatine, pectin or lime juice clears the cashew juice from remaining undesirable contents.
The decortication of cashew nuts is hampered by the liquid contained in the cashew nut shell. This liquid is a viscous, oily liquid, pale yellow to dark brown in colour with a bitter taste and caustic properties; it causes blisters on human skin unless precautions are taken, and it will spoil kernels on contact. In traditional artisanal cashew processing the nuts are put in an open pan over an open fire and stirred continuously to avoid scorching until they start burning, then they are thrown on sand to extinguish the fire and to remove the remaining humidity on the outer skin.
In industrial processing the nuts are graded in different size classes and rehumidified at about 16% moisture by spreading water over them for about two days to make the kernel elastic and to fill the cells of the shell with water. Then, they are roasted in a hot oil bath heated to 192°C for about 90 seconds depending on the size of the nuts. Through the roasting process, the cells of the shell break and about 25 % of the shell liquid flows into the bath. The remaining liquid on the outer shell is removed with sawdust.
Both the artisanal and the industrial methods make the shell brittle so that they can be broken easily.
Another method to avoid contamination of the kernel with the shell liquid is to deep-freeze the nuts and split the shells while frozen.
There are different methods for manual cashew shelling. The simplest consist of placing the prepared nuts on a stone using a hardwood stick to crack the shell. A semi-mechanised process uses a pair of knives shaped in the contour of half a nut. The knife system is also used in industrial plants. In another industrial processing method centrifuges are used to crack the shells; shells and kernels are then separated in an air stream, heated shells are lighter and blow away.
After shelling the kernels have to be dried to about 6% moisture content, thereafter the testa can be peeled off easily. Kernels are then graded, rehumidified to 8% and packed in airtight containers filled with carbon dioxide (CO2) and sealed. The CO2 inhibits infestation by insects and is slowly absorbed by the nuts thus producing a vacuum that prevents shaking and breaking of the nuts during transportation.
Cashew apple processing:
Apples are steamed under pressure or cooked in a 2% salt solution to remove the astringency. Addition of gelatine, pectin or lime juice clears the cashew juice from remaining undesirable contents.
Information
on Pests
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Helopeltis bugs, also known as
mosquito bugs or mirid bugs, are the most important pests of cashew. These
bugs are slender, delicate insects, about 7- 10 mm long with long legs and
antennae, the antenna being nearly twice as long as the body. The females are
red and the males brown to yellowish red. They lay eggs inserted into the
soft tissue near the tips of flowering or vegetative shoots. Nymphs (immature
bugs) are yellowish in colour. Both adults and nymphs feed on young leaves,
young vegetative and flowering shoots, and developing fruits.
Attacked leaves are deformed and show angular lesions, particularly along the veins, which may drop off, so that the leaves appear as if attacked by biting insects. Feeding on the stalks of the tender shoots causes elongated green lesions, sometimes accompanied by exudation of gum. Severely damaged shoots die back due to the effect of bug saliva in combination with fungi, which enter the plant tissue through the feeding lesions; the subsequent development of numerous auxiliary buds causes a bunched terminal growth known as 'witches broom'. In case of serious infestations the trees may appear as if scorched by fire. Bug feeding on developing apples and nuts causes brown sunken spots. The growth of trees is seriously retarded and fruit formation of attacking flowering shoots is reduced. |
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What to do:
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Adult bugs are reddish brown in
colour and 12 to 14 mm long. Nymphs are red brown to green brown in colour
and have long antennae. Bug feeding causes necrotic bruise-like depressions;
a hard lump develops, which can be easily removed when the fruit is peeled.
The bug sucks on the developing fruits causing pockmarks. The kernels are
also affected showing spots, which lower their market value.
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What to do:
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The cashew weevil is large weevil,
about 20 mm long, and of a knobbed appearance. It is dark grey-brown in
colour. The female weevil lays single eggs in small holes in the bark of the
trunk or branches. The larvae are legless grubs, whitish in colour with a
brown head. They bore through the bark and move downwards tunnelling under
the bark while feeding on the sapwood.
Brown-black gummy frass is seen on the trunk and main branches. Heavily attacked trees become ringed by damaged sapwood and eventually die. Neglected plantations are likely to be severely attacked. Fully-grown larvae pupate in a chamber about 2 cm below the bark. |
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What to do:
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Adults of the red banded thrips
are dark brown or blackish. Nymphs are pale yellow with a broad transverse
red band on the dorsal side of the abdomen. Thrips attack older leaves,
flowers and shoots. Attacked leaves drop off leaving bare shoots with few
young leaves at the tip. Infestation of flowers causes poor fruit formation.
Locally limited infestations may cause considerable damage.
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What to do:
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The long-tailed mealybug
(Pseudococcus longispinus) attacks shoots, inflorescences, apples and nuts.
Affected parts appear completely white. Trees infested during the flowering
stage fail to produce fruits, whereas those infested at the nut swelling
stage produce discoloured nuts, which result in a lower grade. However,
cutting tests showed no difference in kernel outturn between clean and
discoloured nuts. Mealybugs have been a problem for cashew growers in
Tanzania.
The body of the adult female is 2.0-3.6 mm long, soft, elongate oval and somewhat flattened. |
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What to do:
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Adults are a long horn beetles,
with a body length of 25-35 mm and with antennae longer that the body. The
head and the thorax are dark brown; the wing cases are orange with large
black blotches giving them a reticulate appearance. Adult beetles girdle
branches from 3-8 mm in diameter leaving a V-section cut; only a narrow,
central pillar round the pith zone is left, which eventually breaks off.
Female beetles lay elongated eggs in transverse slits made in the bark of the
girdled branch at points above the girdle. Larvae are yellow, in colour and
reaches a length of 45 mm when fully grown. They mine in dead wood of the
girdled branches. Pupation takes place in the dead wood. The lifecycle takes
one year. This beetle is a common but usually minor pest of cashew in the
Coast Province of Kenya. However, neglected plantations may be severely
damaged. It is also present in Tanzania.
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What to do:
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Information
on Diseases
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The disease attacks young plant
tissues and can cause severe crop loss when it infects flowers, which turn
black and die. Young leaves, cashew apples and nuts are similarly affected.
Infected young terminal shoots die back. The disease is promoted by warm,
damp conditions.
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What to do:
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This disease is particularly
serious in coastal areas south of Dar es Salaam in Tanzania. Infected
panicles and leaves are coated with white, powdery fungal growth. In severe
attacks the entire panicle may be infected and the fruit and nuts fail to
set.
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What to do:
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LEMON GRASS/ MCHAICHAI
Lemon grass is also known as Cymbopogon citratus, and has certain therapeutic properties and the reported benefits of using it internally, in the form of a herbal tea (infusion) are listed below.
Lemon grass is used for the following
Cymbopogon citratus benefits:
• reducing fevers
• stomach cramps
• flatulence and colic
• easing arthritic pain
• general digestive aid
PS: Especially suited for digestive problems in children
Other benefits are soil conservation and recreation at home compounds.
Waziri
wa Mambo ya Nje na Ushirikiano wa Kimataifa, Bernard Membe akizungumza
na waandishi wa habari wapo picha juu ya ujenzi wa bandari ya Bagamoyo
utakaokuwa wa aina yake Afrika Mashariki na Kati, unatarajiwa kugharimu
dola za Marekani bilioni 10 na kukamilika kati ya miaka mitano hadi saba
ijayo. kulia ni Mkurugenzi Mtendaji wa CMHI ambaye pia ni Makamu wa
Rais Mtendaji wa kampuni ya China Merchant Group Dk Hu Jianhua.kikao
hichi kimefanyika leo jijini Dar es Salaam
Waziri
wa Mambo ya Nje na Ushirikiano wa Kimataifa, Bernard Membe na Mkurugenzi Mtendaji wa CMHI ambaye pia ni Makamu wa
Rais Mtendaji wa kampuni ya China Merchant Group Dk Hu Jianhua. na wajumbe wengine mara baada kikao kilichofanyika jijini Dar es Salaamjuu ya ujenzi wa bandari ya Bagamoyo
utakaokuwa wa aina yake Afrika Mashariki na Kati
Rais Jakaya Mrisho Kikwete akiweka sahihi kwenye kitabu cha maombolezo
nyumbani kwa aliyekuwa Waziri wa Viwanda na Biashara Marehemu
Dkt.Abdallah Kigoda mjini Handeni Alhamisi Oktoba 15, 2015
Rais
wa Jamhuri ya Muungano wa Tanzania,Jakaya Mrisho Kikwete akiungana na
wananchi wa Handeni Mkoani Tanga, katika kumzika aliyekuwa waziri wa
Viwanda na Biashara Dk. Kigoda Rais akiwa na chepe ya mchanga.
