Cashew Tree

Cashew is a tropical evergreen tree in the family Anacardiaceae grown for its edible fruits (nuts).The botanical name of cashew is Anacardium occidentale. Cashew originates from Brazil. Portuguese missionaries took it to East Africa and India during the late 16th century, where it became abundant at low altitudes near the seacoast. Cashew trees have an economic lifespan of 25 years after which time they are replaced in commercial plantations. Parts of the cashew must be handled with care by susceptible individuals because it is related to poison ivy and poison sumac and can cause an allergic reaction in some people.



The cashew tree has a branching main trunk and characteristic domed crown. The thin foliage of the tree is limited to the ends of the branches and is made up of oval-oblong leathery, shiny dark green leaves. The leaves are smooth with pronounced veins and midrib and possess petioles which are swollen at their base. The tree produces numerous pinkish-white flowers on drooping panicles and a kidney shaped true fruit (nut) which is approximately 3 cm (1.2 in) long with a gray-brown shell and develops from a fleshy accessory fruit, sometimes referred to as the 'cashew apple'. The cashew apple is pear shaped and red to yellow in color.


Table of Contents


Height(Avg)

15 - 46 feet


Width-Circumference (Avg)

3 - 10 feet


Approximate pH

5.0 - 6.5


Planting Cashew Tree


1. Plant your fresh cashew seed in sandy soil. Sandy soil ensures a lack of water logging.Avoid clay based soil and whatever type of soil you use, ensure that it allows for free flowing irrigation as water-logging can lead to damaging the tree.

  • Buy cashew seeds specifically for growing from gardening supply stores. Cashews sold for consumption, even raw ones, are not viable because their protective shell has been removed.

  • Always wear gloves when handling the seeds, so you do not touch them directly. Cashew seeds contain irritants similar to poison ivy, that can cause itchy skin.


2. Plant your seeds 10 centimetres (3.9 in) deep to make room for expansion of roots. If you plant multiple trees, plant them 30 feet (9.1 m) away from each to ensure adequate room for growth.

  • Using the freshest seed possible will provide the best results so plant as soon as you get hold of it.


3. Use an area that receives moderate rainfall. Cashews can’t sustain in areas with heavy rainfall or wind but can thrive in extremely hot temperatures up to 50 °C (122 °F). Because of this, tropical areas that are very warm and receive medium levels of rainfall are ideal. If there is too much rain, the roots will drown and the tree will die.


4. Ensure your tree has access to at least 6 hours of sunlight per day. Cashew trees thrive in warm, sunny climates and if the tree doesn’t receive this much sunlight then it will grow slowly and eventually may not even flower. Ideal locations for growing cashew trees include:

  • Open fields

  • Farmland

  • On top of hills that will not be too windy


Cashew Tree Care


Sun


Cashew tree needs at least 6 hours of direct sunlight. In the shade, it grows slowly and doesn’t produce fruits.


Soil


Cashew prefers poor sandy and laterite soil with a pH level of around 5-6.5. Never grow cashew tree in a clay-rich soil. It is heavy and encourages waterlogging, and in the case of a growing cashew tree, the soil you use should be well-drained in a way that water will flow smoothly.


Water


Cashew trees are moderately drought tolerant once established, but they produce more fruits if watered regularly. During the summer, water weekly or twice and deeply. Reduce or withhold watering during winter. Overwatering can harm or even kill your cashew tree, so water only if the soil is dry and let the soil to dry out between spells of watering.


Fertilizer


Cashew tree needs regular application of fertilizer to thrive and produce fruits. Use slow-release fertilizer according to the product instructions given on the packet, around the base of the tree, every two months, during the growing season. Also apply compost or farm manure once in a year, around 30 pounds (15 kg) on the surface of the soil to a mature tree.


Pruning


Prune cashew trees regularly to remove weak, dead, and entangled branches and branches that are infested with diseases or pests. Also, cut overcrowded branches to promote vigorous growth.


Mulching


Do mulching around your cashew tree with organic matters to prevent weeds and to conserve moisture.


Harvesting the Cashews


1. Pick the fruit once it is rosy red and the shell is a dark grey color. This color means that the fruit is ripe and the shell has fully formed. This will often occur around winter or the rainy season (depending on the type of climate you’re in).



2. Separate the shell from the fruit (cashew apple). The shell has a kidney shape and is attached to the fruit on one end. Twisting the shell should remove it from the fruit.

  • The fruit is edible also, is full of nutrients, and many people use it in smoothies or even eat it raw.

  • You can store the shells for up to two years before further processing.



3. Roast the unprocessed shells on a pan covered in fine sand for 10-20 minutes. This is done because inside the shells is the nut, but also an extremely acidic, caustic oil that will burn you. It’s extremely important to cover the shells with either a lid or have them submerged completely in sand during this process.

  • The temperature needs to be around 190 °C (374 °F) for this process. Anything higher will result in vaporization of the oil into fumes (which should be avoided) and a drying out of the nut inside.

  • Use an old baking tray or a disposable one as the residue of the oil can be difficult to fully remove after.


4. Sieve the shells out from the sand. The shells need to be washed in water with detergent before further handling to prevent any potential contact with the remaining oil. Be careful not to make contact with your eyes or face during this process due to the possibility of remaining oil.


5. Crack the shells. The nuts are ready to be extracted from within. They will have a coating around them that needs to be peeled carefully using the edge of a knife before proceeding to the next step.



6. Roast the nuts in coconut oil for 5 minutes. This is done to get rid of any final residue of the toxic oil and ensure they are okay to eat. The oil should be heated to around 150 °C (302 °F). The nuts are now ready to be consumed.


Pests and Diseases


Pests

1. Cashew weevil Mecicorynus loripes

Symptoms: Brown-black gummy frass (insect excrement) on trunk and branches; girdling of branches; plants dying

Cause: Insect

Comments: Adults large and gray-brown with knobbly appearance; larvae legless grubs which are white with a brown head

Management: Remove bark from infested areas and destroy any larvae or pupae found, this process should be repeated every month for up to six months; severely infested trees should be removed and destroyed; remove all adult weevils from tree prior to destruction and also remove bark and kill all larvae and pupae

2. Coconut bug Pseudotheraptus wayi

Symptoms: Necrotic lesions on fruit which develop into hard lumps; pockmarks of fruit; spotting on kernels

Cause: Insect

Comments: Adults are red-brown in color; nymphs are red-brown to green in color

Management: Conserve natural enemies by avoiding unnecessary applications of insecticides

3. Helopeltis bugs

Symptoms: Deformed leaves with angular lesions along veins; leaves may drop from plant; elongated green lesions on young shoots which may exude gummy substance; dieback of shoots

Cause: Insects

Comments: Helopeltis bugs are slender with long legs and antennae; antennae twice as long as body; females are red; males brown; nymphs are yellowish in color

Management: Monitor crop regularly for signs of damage; conserve populations of natural enemies, weaver ants can reduce populations; avoid interplanting cashew with other crops which are hosts for helopeltis bugs such as tea and cotton


Diseases

1. Angular leaf spot Septoria anacardii

Symptoms: Angular cream colored lesions with dark-brown margins on leaves of seedlings; angular black lesions with chlorotic halos on mature trees; defoliated seedlings

Cause: Fungus

Comments: Some dwarf types of cashew are resistant to this disease; disease is widespread in cashew growing regions of Brazil

Management: Currently no control measures are used

2. Anthracnose Colletotrichum gloeosporoides

Symptoms: Water-soaked lesions on leaves, twigs, flowers or young apples which develop into orange-brown or red lesions;

Cause: Fungus

Comments: Disease emergence favored by rainfall and high humidity

Management: A protective coating of copper-based fungicide on susceptible parts of plant can prevent the disease; fungicide should be applied when buds begin to expand through to fruit set but are not required during dry periods

3. Black mould Pilgeriella anacardii

Symptoms: Chlorotic spots on upper surface of leaves which spread to lower surface as infection progresses; dark-brown to black fungal patches on leaves; leaves shrivelling and dropping from plant

Cause: Fungus

Comments: Damage most severe on dwarf cashew varieties


Benefits of Cashew


Cashews prevents heart disease


Cashews are an excellent source of dietary fats. These fats are required by the body to absorb nutrients such as fat-soluble vitamin A, D, E, and K, along with essential fatty acids that help with brain development and prevent blood clotting.

Some of the vital healthy fats are polyunsaturated fats (PUFA) monounsaturated fats (MUFA), which help with reducing LDL cholesterol present in Cashews. LDL cholesterol is extremely harmful as it can lead to various cardiovascular diseases and lowering its quantities in the blood helps significantly reduce the risk of heart disease.

Cashews also increase the levels of HDL (good cholesterol) in the body, reduce blood pressure, and reduce triglycerides, all of which contribute to a healthier cardiovascular system.


Cashews reduces the risk of diabetes


Cashews are a delight for diabetics as they control the blood sugar levels and regulate insulin. They even help lower the risks of developing type 2 diabetes.


Cashews works as a Cancer Chemopreventive Agent


Cashews have a variety of antioxidants such as anacardic acids, cardols, and cardinols, which is why they are quite effective for people who are undergoing treatment for cancer or tumors. Many cancer patients are advised to consume ground cashews as they are a rich source of protein that can be absorbed by the body quite easily.


Cashews promotes the development of Red Blood Cells (RBCs)


Red blood cells (RBCs) are one of the most important types of cells present in the blood as they help transport oxygen from the lungs to the brain and other organs. Cashews are rich in copper, which helps with the metabolism of iron, formation of RBCs, and keeping the immune system healthy and functional at all times.

Having an optimal level of RBCs in the body leads to better organ functions, reduced risk of tissue damage, and just more energy as a whole. Without RBCs, the organs start to deteriorate. Moreover, copper is an important nutrient for the body as without it, one can be at risk for anemia, osteoporosis, and irregular heartbeat.


Cashews reduces the risk of anemia


Cashews have dietary iron in them. This nutrient helps with transporting oxygen all over the body to various organs, and also helps with the way the enzymes in the body function. Making cashews a regular part of the diet can help prevent fatigue, anemia, and even decrease the body’s susceptibility to random infections. Having just a few nuts on a daily basis can really go a long way for the health of your body as a whole.


Cashews boosts bone and oral health


Cashews are rich in phosphorus, which is needed for the development healthy bones and teeth. Phosphorus is also needed to properly synthesize proteins, absorb carbohydrates from food, and fats in the maintenance of cellular health.


Cashews prevents gallstones


Gallstones are mainly deposits that consist of cholesterol that form into a stone like structure inside the gallbladder. They can impair the functioning of the gallbladder and are also quite painful. Including cashews in your daily diet can help you prevent the occurrence of gallstones.


Cashews boosts immune system


Cashews contain high amounts of zinc, which are extremely essential when it comes to boosting the immune system. It helps strengthen the system against microbial infections, helps with the healing of wounds, and protein synthesis. Pregnant women are often encouraged to eat cashews as they help with the development of the baby.


Uses


Cashews are quite popular and are used while baking food, as well as while cooking savoury meals. They can be crushed and added to a variety of vegetarian and non-vegetarian dishes, or can just be eaten raw, roasted, and/or with salt.


Cashew Nut Shell Liquid: The cashew nut shell liquid (which is a byproduct of procuring cashews) is used to prepare paints, insecticides, drugs, resins, anti-termite treatments for timber, and plastics. It also has antibiotic effects and is used medicinally to treat a sore tooth, ringworm, scurvy, leprosy, warts, and elephantiasis.


Cashew barks and leaves: The cashew bark and leaf can be used to treat diarrhea as well as colic. The leaf extract also helps with reducing blood sugar levels and blood pressure. The bark has astringent properties and an infusion of the bark can be used to treat oral ulcers, sore throat, and even influenza. By boiling the leaves of the tree in water, one is left with an anti-pyretic that can be utilized to treat ache and pains all over the body.


Cashew Apple: The cashew fruit, also known as the cashew apple, has anti-bacterial uses and can treat ulcers in the stomach and gastritis. Since its juice has high contents of vitamin C, it can be used to prevent scurvy. A tea made with the juice can also treat dysentery. It can also be used to cure thrush in infants.


Cashew apples are widely used in South America to create sauces, curries, and jams, and is also often fermented into vinegar and liquor. This can only be had after steaming or boiling as its skin can often induce an allergic reaction.


Cashew Oil: Oil extracted from cashew seeds also has its share of uses. It treats cracked heels. When cashew seeds are powdered, they can be used to cure snake bites as they have a antivenom effects.


Other uses:


As well as the nut and fruit, the plant has several other uses. In Cambodia, the bark gives a yellow dye, the timber is used in boat-making, and for house-boards, and the wood makes excellent charcoal. The shells yield a black oil used as a preservative and water-proofing agent in varnishes, cements, and as a lubricant or timber seal. Timber is used to manufacture furniture, boats, packing crates, and charcoal. Its juice turns black on exposure to air, providing an indelible ink.


Animal feed: Discarded cashew nuts unfit for human consumption, alongside the residues of oil extraction from cashew kernels, can be used to feed livestock. Animals can also eat the leaves of cashew trees.



12 views0 comments

Recent Posts

See All