Origin and distribution
The pecan nut belongs to the family Juglandaceae and native to South-Central North America and widely grown in the southern USA. Major pecan growing countries are USA, Mexico, Israel, South Africa, Australia, Peru and Turkey. The Spaniards brought the pecan into Europe, Asia and Africa beginning in the 16th century. In India, pecans were introduced from the USA by Punjab Government in 1937. Eight cultivars were planted at Govt. Fruit Farm, Palampur, Himachal Pradesh, which became a major source of planting material in the Himalayan region.
NBPGR also introduced 13 cultivars from the USA in 1963 and conducted experiments on its adaptability, propagation and production potential. General description: Pecan nut has the recognition of being called “queen of nuts” because of its excellent kernel characteristics. All the species of the genus Carya are together known as “hickories”. The pecan trees are about 15-20 m tall have long tape root system, spreading canopy and woody in nature.
Pecans varieties are monoecious and dichogamous. The male flowers are found along the stem in hanging position, three branched catkins and the female flowers are found at the end of a twig. Fruits mature in the month of September- October. The outer husk is thick and green, which turns brown at maturity and splits off into four sections to release the thin shelled nut.
Nutritional value and uses
Pecan is a rich source of fat, protein, carbohydrates, minerals and vitamins as revealed from the proximate composition of 100 g kernel given below. Nut contains more antioxidants than other nuts. It has medicinal value too, the leaves ground up and applied to the skin as a poultice for treating ring worm. The Kiowa utilized pecan bark in a decoction that was administered to the patients suffering from tuberculosis.
Pecan nut can be grown in varied soil conditions, sandy loam, deep, fertile soil, rich in organic matter, well aerated and well drained but should have good moisture retaining capacity. It grows satisfactorily at an elevation ranging from 1000-2000 m and needs warm temperate climate, but the chilling requirement of 500-600 hour below 7.20C is desirable for the cultivars originating from the temperate region. It is propagated by grafting on to the rootstocks raised from the seedlings in the month of February when sap movement begin in late winters while chip budding is done in June.
Planting of 1 or 2 years old healthy grafted/budded plants from the nursery is done in late winters in the pits made at a distance of 8 x 8 m. If due care was taken, pecan nut starts fruit bearing in the 5th year onward of a plantation. As pecan nut trees advance the age, they become larger and get crowded making pruning, spraying and fruit harvesting operations difficult. Pruning is often done for dried branches. Training is done using central ladder system keeping the height of lowest branch at 1 meter. It has been recommended that pecan trees should be applied 100 kg FYM and 500 g NPK mixture in the ratio of 2:1:1 /tree every year once the pruning is over.
The doses can be increased further as the tree advances in the age. Pecan nut trees are prone to zinc and manganese deficiency, which can be prevented with foliar application of zinc sulphate and magnesium sulphate each @ 0.5%. The trees do need irrigation especially when they are young but water requirement reduced as they grow old. Pecan should be harvested at proper maturity when the shucks split open and separate from the nuts. Owing to the large canopy, the harvesting is done with the help of bamboo poles. Collected nuts should be spread out on the clean soil surface, dried properly and stored in cool and dry conditions.
We are maintaining 49 accessions of pecan which have been introduced from USA (47), USSR (1) and Argentina (1) and it is also the largest collection of pecan germplasm in India Of these collections, only 10 accessions have been characterised for different horticultural traits while other are yet to reach bearing stage. The variety ‘Mahan’ has been found vigorous, prolific-bearer, and have the best quality nut. Other like Major, Busseron and Desirable are equally good and found satisfactorily fruit bearer.World’s largest germplasm of pecans is also being maintained at Brownwood Station of USDA, USA. Other important cultivars of pecan nut being grown in different countries include Choctaw, Cheyenne, Desire, Mahan, Caddo, Cape Fear, Forkert, Kiowa, Oconee, Houma, Wichita, Western, Tejas, Pawnee, Sioux, and Mohawk.
- National Bureau of Plant Genetic Resources Regional Statio, Phagli, Shimla