Walnut belongs to the family Juglandaceae and genus Juglans. The family consists of about 60 species, 21 of which are placed in the genus Juglans. Walnut tree is medium to large with spreading crown. Nuts are borne singly or in clusters and a green, fleshy husk surrounds it, which splits irregularly at maturity. Walnut growing is extremely sensitive to soil conditions and should only be planted on the most suitable frost free, fertile, well drained and deeply rootable sites. The wood of walnut is considered as one of the most valuable woods in the world for high-grade furniture and joinery. Walnuts consist of mostly omega-3 and omega-6 polyunsaturated fatty acids, which are essential dietary fatty acids and helps in the prevention of coronary heart disease.
Walnuts are used in cakes and toffees. It is specially used in making traditional sweets/desserts, breads, muffins and cookies. They are rich in oil content and are used in cookery, as in garnishing sometimes and could be eaten plain as well. In some countries the walnuts are preserved in vinegar, they are called pickled walnuts. Walnuts along with olive oil help in reducing the inflammation in the arteries after meals which can cause heart diseases. The Black walnut is of high flavor, but due to its hard shell and poor hulling characteristics it is not grown commercially for nut production.
The commercially produced walnut varieties are nearly all hybrids of the English walnut. Walnuts are one of the several high nutrient density foods. About 100 grams of walnuts contain 15.2 gram protein, 65.2 gram fat, and 6.7 gram dietary fiber. The protein in walnuts provides many essential amino acids. Compared to certain other nuts, such as almonds, peanuts and hazelnuts, walnuts (especially in their raw form) contain the highest total level of antioxidants, including both free antioxidants and antioxidants bound to fiber. These specially charter help for prevention of different disease in body. Its a big source for removal of reactive oxygen species. Walnut tree provides timber and barks.
Walnut timber and bark are used in making of local furniture and cleaning of teeth. The leaves of black walnut are used for treatment of ringworm, to make a green dye, and as an insecticide. Walnut helps control cholesterol level, strengthens walls of blood vessels and prevents diabetes, supports immune system, helps improve memory and speeds up recovery after serious operation.
Quality black walnut wood demands high market prices for many uses including furniture, cabinets, interior architectural woodwork and flooring. The furniture made from walnut wood is considered as the most costly furniture. In Pakistan, generally walnuts are propagated through seed that come into bearing after 8-10 years and optimum yield is not expected until the plant reaches the age of 12-15 years. In contrast, the grafted plants come into bearing within a period of 3-5 years and reaches optimum production after 6-8 years. However, the main problem in the region is the non-availability of grafted plants, as walnut is very difficult to propagate asexually. Not all scion varieties show similar response to graft take success. But the lack of official support and negligence, deforestation, non-plantation of new trees and attack of stem-borer has endangered this great agricultural asset; fortunately Pakistan is rich in the production of walnut.
A large number of walnut trees are present in the areas of Galliat, Abbotabad, Swat, Dir, Shangla, Buner, and Chitral. If these tree species are properly cared on government level, they are not less than for the gold economy of the country.In my opinion, Pakistan still has a lot of uncultivated land and land unutilized we term as culturable waste. The genetically superior walnut tree can be grown in any soil and climate under a well-drained soil condition. This commercial tree is highly suitable for cultivation in central and northwestern provinces of Pakistan. The tree has several harvests and is the fastest growing tree; it may grow 30 to 40 feet in a single season in some regions of the world. It has huge benefits of bringing rain in the area.
The government needs to provide expert advice, walnut saplings and seeds, pesticides/insecticides to farmers to grow more trees. Walnut depending on its quality and taste is sold at Rs 30,000-35,000/50kg in the market. The brighter the kernel, the better is the price earn by famer. So the local communities should pay attention towards cultivation of this tree in their orchards and left over patches and the government must take steps towards the development and care of these species present in wild lands and forest areas so that with too many benefits and huge importance, they can really appear as gold for our country.
The writers are associated with the Institute of Horticultural Sciences, University of Agricultural Faisalabad, Pakistan.