WALNUT: The Privileged Nut Fruit of Kashmir Valley

The most attractive are those obtained from regia and especially from burl walnut. The fruits of the walnut tree have always been considered strategic for human alimentation, due to their extraordinary energy values; this appreciation is especially deep-rooted in those countries which are characterized by rigid winters. This was also used to fight caterpillars and worms in orchards and vegetable plots. Walnut husks were widely used to produce various kinds of brown dye, and tannins were extracted to be used, for example, in leather and clothes industries as well as in carpentry. In the past, one of the main uses of walnut shells was to burn them, mainly on braziers or fire pots. Although gas and oil energy is largely diffused around the World but in Kashmir people still use shells in the fire pot Kangre, which is popular in Kashmir. Nowadays, the chemical and aeronautic industries utilize walnut shells as abrasive peelers.
In India, walnut production was earlier confined to Jammu & Kashmir but now it is also cultivated in Himachal Pradesh, Uttarakhand hills and Arunachal Pradesh. Besides India, major walnut growing countries are China, USA, Iran, Ukraine, Turkey and Mexico. China stands first, followed by Iran, United States and Turkey while India stands seventh in production list. Walnut is an important crop grown in Jammu and Kashmir and contributes around 98 per cent of the country’s production. Jammu and Kashmir still enjoy monopoly on this fruit as it is the only State in the whole country where it is produced substantially, however its cultivation has spread to other parts of India as well. Most of the trees here in Kashmir are of seedling origin and no standard variety is generally grown here, though Sheri-e-Kashmir University of Agricultural Sciences and Technology (SKUAST-K) has released two walnut cultivars, Hamadan and Sulaiman, having high yield potential and shelling percentage.
Introduction of other varieties like Lake English, Drainovsky and Opex Caulchry have also been found promising. The state produces about 165024 M tonnes of walnut from an area of 87280 hectares. Walnut cultivation is common in Badrawah, Poonch, Kupwara, Baramulla, Bandipora, Gandarbal, Budgam, Srinagar, Anantnag and other areas as well. Now walnut is grown in Himachal Pradesh and Uttarakhand as well but to a limited extent. In Himachal Pradesh, it is grown in a couple of districts. Around 50 hectares are under its cultivation in the Mandi district, Chamba district has just over 55 hectares under it. Also, there is some area in Shimla district under this crop.
In Italy, the proverb “Walnut and bread, a meal of the King”, shows the importance of walnuts as food. The walnut is a versatile nut in many recipes across the World. Creamy sauces or ground kernels are used in walnut producing countries to dress their traditional food such as pasta in Italy, meat (in the Balkans and Caucasian regions), fish and chicken (in China), and pastry (everywhere). In Iran, the Fesenjan national dish, with duck or chicken stew simmered with walnuts and pomegranate juice, is seasoned with cardamom and sprinkled with chopped walnuts. Immature fruits of walnut can be utilised for preparing various products like pickles, chutneys, fresh juices and syrups. The fruit has excellent flavour and is mainly consumed as a dry fruit. Commercially, it is used for preparation of bakery products, chocolates, ice-creams, oils, confectionary and salad products. Shells are used in glue, plastics and for making solutions for cleaning and polishing surfaces.
Walnut bark and nut hulls are used as ingredients in naturopathic remedies. Today walnut and its products are being promoted for treating a variety of skin ailments (ringworm, athlete’s foot, jock itch, psoriasis, eczema, wounds) constipation, internal parasites and it has been recommended as a gargle to soothe sore throat. Walnuts are rich in proteins, fat, minerals and are concentrated source of energy with high essential unsaturated fatty acids such as the Alpha linoleic acid and omega-6 fatty acid. These contain a good amount of Vitamin B group and are the richest in vitamin B6 among all the nuts. Walnuts are rich in amino acids (glutamic acid, arginine and leucine) particularly sulfured one-taurine (2-aminoethylsulfonic acid) is important as it is involved in many functions of homeostatic regulation, thermoregulation, anti-aging, nervous conduction and protection against oxidative stress.
Research has suggested that antioxidants help to protect from certain chronic diseases of aging, including cardiovascular, neurological and carcinogenic ailments due to their ability to control free radicals – known to negatively influence healthy aging. Walnuts are known for their high antioxidant content. Walnut consumption is found to be an important component in lowering blood cholesterol concentrations, thus supporting walnuts as part of a heart-healthy diet. The walnut diet significantly improved the cholesterol level ratios, which are important predictors of coronary heart disease. Certain components in walnuts including alpha-linolenic acid, antioxidants and phytosterols, may offer potential cancer fighting properties in a synergistic manner as well. Including the right type of fats, like those found in walnuts, is particularly important to people with diabetes. It has been found that there is a positive effect of a moderate fat diet, inclusive of walnuts, on blood lipid profiles in patients with type 2 diabetes.
The domestic and external demand for walnuts has been increasing over the years. Indian walnut production is projected to reach around 75,000 tonnes by 2020. So the country needs to bring in additional area and increase productivity to meet the projected demand. In India even though the domestic and external demand for walnut has increased over the years but at the same time its cultivation and production could not develop rapidly due to a number of constraints including insufficient scientific research, improper and random classification, long gestation period, pre-harvest, post-harvest problems, uneven yields (estimated at 18-50 kg/tree/year with nut sizes varying from 24-32 mm) and pest infestation keep production relatively stagnant.
Although there are various insect pests reported on walnut in Kashmir valley but among them walnut weevil, Stem borer, Hairy caterpillar, Walnut aphid, Duskey veined aphid, Chaetoprocta, gypsy moth, bark beetle, walnut blister mite and Tortrix moth present a severe threat to the crop and cause considerable economic damage to the crop. By following pest management practices the damage can be reduced to a large extent. For efficient management of walnut, weevil fallen infested fruits should be collected and buried deep in the soil so as to have reduced population in next year. If needed, spray chlorpyriphos or endosulfan in the month of July. For stem borer and bark beetle Plugging the infested plant with cotton impregnated with 0.1% of dichlorvos and White washing of the trees with lime (slaked) is recommended. Walnut blue butterfly (Chaetoprocta) is a monophagous pest of walnut having only one generation in a year. Second instar larvae of the pest is the most damaging stage causing severe damage to the tree by defoliating its leaves. The damage has been observed most severe in Anantnag belt of Kashmir valley.
For the management of the pest, chemical spay by imidacloprid or dimethoate should be done in the first week of May when larval population attains its peak. Chemicals that are effective for the management of Walut aphids are Imidacloprid or Dimethoate. The walnut blister mite is another pest that damages walnut plants in nursery and orchards. Adult mites are very small and cannot be seen with naked eyes but their damage can be observed on the lower surface of leaflets where they feed, causing characteristic blister like swellings on the upper surface of leaflets.
Often, it is better to discard infested parts of the plants than to attempt the control of the problem with pesticides but in case of severe damage spraying the plants with dicofol can provide effective control. Hairy caterpillar (gypsy moth) is another pest that strips off foliage often completely from the trees in infested areas. Burlapping of tree trunks with gunny bags and collection and destruction of gypsy moth larvae in early summer and egg masses in late summer is an efficient management method for the control of the pest. Tortix moth caterpillars after hatching from eggs in month of May bore into nutlets and feed on green hull inside. Caterpillars do not enter the fruit but feeds inside the husk thereby turning it black and reducing its market value. For efficient management of walnut Tortrix moth infested fruits should be collected and buried deep in the soil so as to have reduced population in next year.
Jammu and Kashmir government proposes to set up a Walnut Board in the State to give a boost to walnut production in a big way on scientific lines by setting up scientific walnut processing units in various areas of the State. But still more needs to be done. Right now need of the hour is to open up high technology poly-houses to increase the production, popularise dwarf varieties and introduce high-yielding strains/varieties. This will ensure economic growth of the State in general and farming community in particular as horticulture is the backbone of the State’s economy. The close coordination between Horticulture Department and Sheri-e-Kashmir Agriculture University of Sciences and Technology is imperative so that maximum farmers are benefited.
(Author is alumna of SKUAST-K)
arshad.abbas5@gmail.com