hinyere Anyanwu,[email protected]
Walnut, an edible, rounded and delicious seed enclosed in a hard husk which grows on walnut tree, is one of nature’s gifts to humanity, loaded with healthy nutrients. Walnut, also known as heart-healthy nut, is well loved in Nigeria as well as across the world. Its wide acceptance means investment in it on a commercial level will be profitable.
Walnut contains essential fatty acids, a good amount of proteins, vitamins, essential minerals and carbohydrates. Other nutritional contents of walnut include Omega 3-fatty acids, which are known to increase brain performance.
Walnut farming has attained global increase due to its rising importance both for its fruit and quality timber. Countries with the highest walnut production include China, Iran, USA, Turkey, Mexico, Ukrain, India, France and Romania, among others.
Health benefits of walnut
Healthy heart: Walnut is one of the healthiest foods for the heart, which can be attributed to its richness in potassium. The presence of oleic acid, omega-3, alpha linoleic and linoleic acids make it very beneficial for managing coronary heart disease. Walnut also reduces the risk of high blood pressure.
Healthy bone: Walnut is excellent for increasing and maintaining bone density because it is rich in copper, zinc, vitamin B, and calcium. The vitamin B, copper and zinc increase the calcium absorption and retention in the body.
Diabetes management: Type-II diabetes patients can safely consume walnuts almost everyday without any side effects owing to the balance between good fats and nutrients found in walnut.
Cancer prevention: Walnut is filled with antioxidants. From its fruit core to its hard shell, walnut is rich in phenolic acids. Oxidative stress can be a potential cause of cancer acceleration in the body and having a handful of walnuts everyday might prevent this life-threatening disease.
Anti-inflammatory: A recent study showed that walnut, being rich in phenolic compounds and antioxidants, reduces inflammation in all parts of the body and also prevents it from occurring. Healthy skin: The good fats, vitamins, and minerals make the perfect skin-cocktail, especially vitamin E, which is known for its wonderful effects on the skin. The shells of walnuts are used by cosmetic brands to create physical exfoliants for the skin. Moreover, the vitamin B complex increases cell renewal and promotes collagen production.
Healthy sleep: Walnut consumption promotes melatonin production in the body, a hormone that induces and helps maintain a healthy sleep cycle.
Stress management: Foods rich in magnesium and zinc help the mind relax and think clearly. Walnut provides a combination of these minerals to help keep the brain functioning properly without succumbing to anxiety or stress.
Weight management: Walnut is high in good fats and also contains a good amount of fibre. It can be a perfect snack between meals, which helps one to stay full and reduces the craving for junk food.
Non-health benefit of walnut: Apart from the numerous health benefits derived from walnut, growing the trees can be very profitable, as the timber of the matured walnut tree is extremely valuable. Timber from spent walnut trees are used for furniture. It usually takes between 30 and 40 years to reach logging size.
Planting walnut trees
Farming walnut is a long term investment and doing it on a commercial scale requires having enough space and adequate funding especially at the early stage. There is no specific size for a walnut plantation. However, minimum land requirement should start from an acre. The size of the plantation should be such that will contain enough trees because adequate spacing is required to allow for proper exposure to sunlight. Land is a primary requirement for starting this business. Since the focus is on commercial benefits of walnut farming, the land should be sizeable enough. A suggested spacing will be a 12 x 12 grid spacing. If significant results are to be achieved, there is need to properly care for the trees.
Walnut is not an annual crop. It grows on trees and takes time before maturing and being ready to produce fruit. Walnut tree does not grow in a year; it takes years to mature enough to bear fruit. Walnut farming is therefore long term. Once it starts fruiting, harvest can be expected every year. Hence, walnut farming requires a lot of patience.
Soil preparation: Preparing the soil before planting will greatly improve the tree’s performance and promote healthy growth. It is good to have the soil tested to determine if it is lacking in any essential minerals and nutrients. Soil preparation can be done when the ground is not too wet. Roots grow faster when they’re spread out, so the hole should be dug deep and wide enough so the root system has plenty of room to easily expand. Adding organic materials such as compost will improve most soil types because they bind sandy soil particles so they retain moisture and nutrients better.
Sun and good soil: Walnut tree thrives in a sunny place with well-drained, fertile soil. It requires six to eight hours of sunlight and good drainage to keep it healthy. Once the tree is established, it needs little assistance to grow and produce but the tree should be given the best foundation possible. The tree should be planted in the right place because it will be difficult to transplant a year or two after planting.
Pest/disease control: If available, disease-resistant walnut trees are the best option for easy care. Proper maintenance, such as watering, fertilising, pruning, spraying, weeding can help keep most insects and diseases at bay. The following are some of the diseases and pests that attack a walnut tree:
Dieback: Causes a slow death of the branches. The bark changes from normal greenish-brown to reddish-brown and finally grey in colour. The natural control for this is pruning out infected branches promptly. If the disease reaches the trunk, the whole tree needs to be removed.
Caterpillars: Many kinds of caterpillar can damage walnut. These can be treated with Bonide citrus, fruit and nut orchard spray or Bonide thuricide bacillus thuringiensis (BT).
Bark beetle: Young twigs wilt because of boring done by a dark brown beetle, 1/5’ long. The larvae bore into sapwood, which can girdle branches. Remove and burn severely infected trees, peel bark from stump.
Walnut blight: Black, dead spots on young nuts, green shoots and leaves. Many nuts fall early but some will reach full size with husk, shell and kernel black and ruined. This can be controlled with serenade garden disease control or Bonide citrus, fruit and nut orchard spray.
Pruning walnut tree
As the tree gets older, corrective pruning may be necessary. When the tree is dormant, corrective pruning consists of removing broken, interfering, dead, or disease branches. If any branches are crossing, remove one of them. Prune low limbs that may interfere with sprays or irrigation. Remove limbs and shoots growing through the centre, to allow light and air to penetrate. Watering: The tree tends to need a lot of water during its life cycle. During dry periods, the tree should receive a thorough soaking at least once a week. Water the tree at the drip line (the outer perimeter of the tree’s branches) where normal rainfall would occur, and keep away from the trunk.
Harvesting: Harvesting should start in three to seven years depending on the variety planted and growing conditions.
Production capacity/profit potential: Ideally, an acre of walnut plantation should contain about 100 trees. This allows for even spacing and maximum yield. The production capacity of an acre of walnut plantation is up to 6,000 pounds of nuts. The profit potential is huge. For timber alone, a matured tree can fetch between $20,000 and $25,000 at the international market. The profitability of walnut farming business depends on the farmer’s dedication and commitment.