Waseem Sajjad*, Dr. Zaid Mustafa**, Mujahid Ali*
(*Horticulture, College of Agriculture, UOS; **Horticultural Research Station, Nowshera)
Allah has gifted us with lots of wealth in the form of agricultural productions. Agriculture is the basic need of world because without agriculture world can’t survive. Also, agriculture was the first occupation of man in the world. The first man ‘Adam’ when came on earth started his life with agriculture. So, it’s a precious gift for us by Allah. Now a day’s people are doing research in many fields of agriculture for the welfare of mankind. One of the fields in which agriculture scientists are working is pomology (fruits). Many have written different books on fruits. Pecan is also one of the minor fruits on which different articles have been written. Pecan (Carya illinoinensis) belongs to family Juglandaceae (hickory family) is native to Mexico and central region of United State. It is also called hickory nut or walnut. Georgia is at the top in production of pecan, but it is also grown in California, Florida, Mississippi and Hawaii. Pecans were one of the most recently domesticated crops. It is a 32-chromosome species that readily hybridizes with other 32 chromosome members of the Carya genus, such as Carya ovata, Carya laciniosa, Carya cordiformis and has been reported to hybridize with 64 chromosome species such as Carya tomentosa. Most such hybrids are unproductive. Hybrids are referred to as “hicans” to indicate their hybrid origin. A pecan, like the fruit of all other members of the hickory genus, is not truly a nut, but a drupe, a fruit with a single stone or pit, surrounded by a husk. The husks are produced from the exocarp tissue of the flower, while the part known as the nut develops from the endocarp and contains the seed. The seeds of the pecan are edible, with a rich, buttery flavor. They can be eaten fresh or used in cooking and particularly in sweet desserts. One of the most common desserts with the pecan is technically as a central ingredient is the pecan pie. The pecan tree is 20-40 m in height having alternate and pinnate leaves. Foliage is full green. Pecan nuts are a rich source of energy and contain minerals, vitamins, and anti-oxidants. Pecan trees are well adapted to sub-tropical regions and need short frosty winter and long scorching summer. Pecans perform best in well-drained soils having pH 6-7. They produce high yield when they are provided deep fertile soils and enough moisture. There are different cultivars grown all over the world. The most famous grown cultivars are Varton, Bester, Lakota, excel, headquarter, Adam-5 and Shooshani. Pecan trees may live and bear edible seeds for more than 300 years. They are mostly self-incompatible because most cultivars are clones derived from wild trees which show incomplete dichogamy. Generally, two or more trees of different cultivars must be present to pollinate each other. Pecans can be propagated both sexually and asexually. But the seed propagation is mostly used for seedling rootstocks. The first step in the method of propagation is to collect well-filled nuts and physically healthy having no any appearance of the disease. Then remove the husk and dry the nuts to remove the moisture content present in them so to avoid the chance of attack of any fungal disease. But all the moistures are not removed, there should be 5% moisture retained in them. Then with the help of different dormancy breaking methods, dormancy is broken down to help the pecans to germinate early. In Pakistan, pecans are mostly grown in subtropical, tropical and temperate regions. Pecans grown in northern areas of Pakistan are slightly different than grown in other regions. In temperate region’s their nuts are somehow harder to facilitate the performance against frost. Pecan trees are mostly pruned in winters or in summer during dormancy. Pruning is done to increase the vigor of other branches and to maximize the yield. Diseased branches are also removed with other weak branches. Pecan is harvested when the nuts are physiologically ripened and harvested at the time. Harvesting can be done by hand or by mechanical methods. While harvesting it must be sure that the branches do not break down with fruits, therefore, mechanical harvesting should be done. Many machines have been invented for the harvesting of nuts like pecan which may reduce the fruit lose and save the time also. Late harvesting may cause many problems like fruit fall and attack of diseases. Pecans are subjected to wide range of diseases, pests and physiological disorders which can reduce the yield. Pecans are affected by bacterial and fungal diseases, especially in humid areas. Many of the insects and worms feed on leaves, stem and developing nuts. The best season for harvesting is April to July. There are more than 500 pecan varieties with slightly distinctive characteristics like flavor, texture, size, color, shape etc. Most of the pecans in commercial production come from just a few major varieties. The most popular varieties are Cape fear, Desirable, Moreland, Stuart, and natives. Pecans can be stored at room temperature for about 6 months. They are attacked by some insects which can destroy the whole crop. The most common insects are stem borer, aphid, mites and powdery mildew. Pecan trees perform well in the adequate fertilized area. Before applying any fertilizer, the area under the trees must be cleaned by completely removing and destroying any fallen leaves, twigs, pecans and shucks. This type of sanitation performed weekly during the growing season will help to prevent the carry-over of certain diseases and break the life cycle of insects like the hickory shuck worm, twig, girdler and pecan weevil. Properly fertilize pecan trees in mid to late February. Without proper fertilization, pecan trees are more likely to have alternate bearing years as well as an early nut drop. A soil test will help to determine the soil pH and nutrient levels. Nutrients are most readily available at a soil pH of 6 to 6.5. In the absence of a soil test, broadcast 4 pounds of a complete fertilizer, such as 10-10-10 NPK for each inch of trunk diameter (measured at 4 ½ feet above soil level). Do not place fertilizer in holes but broadcast fertilizer evenly beneath the canopy of the tree. Pecan trees also require zinc for proper growth and development as well as good nut production. Zinc deficiency causes a disorder known as rosette. Symptoms of rosette include bronzing and mottling of leaves, early defoliation, dead twigs at the top of the tree, abnormally small nuts, small, yellowish leaves and short thin twigs on older branches with rosettes (clusters) of small yellowish-green leaves at the tips. In general, 3 to 5 pounds of zinc sulfate can be applied to large trees each year to maintain proper zinc levels. Alternately, pecan tree fertilizer containing zinc can be applied. Many pecan fertilizers are available as 10-10-10 NPK with 2% zinc. Apply at the same rate mentioned above for 10-10-10 NPK. Pecans nuts are hard so, they can’t be broken down by hand therefore many machines have been invented for cracking of pecans. Now, the cracking machines are mostly used all over the world. The machine is of two types, electrical cracking machine which uses electricity and the other one is mechanical which doesn’t need electricity, and which can be operated by hand. Pecans can be used to obtain timbers and plywood for the construction of houses and shops. Their woods are strong enough to bear the weighs, so they are being used for many purposes. Pecans are rich source of different nutrients and minerals which are required by the body for good health. They contain protein, energy, fiber, amino acids, fats, starch, and sugar. Also, they contain thiamin, riboflavin, folic acid and vitamin A, B6, C and E. Pecans can give us lots of health benefits including cardiovascular health and digestive health. The fibers in pecan reduces the chance of heart cancer and reduces the risk of coronary heart diseases. Also inhibit the unwanted oxidation of blood lipids. The fibers in pecans nuts strengthen the colon to work at a great level and help in cleaning the gastrointestinal system. They also prevent the constipation and help in digestion. Beside these benefits, they also help in weight loss, reduce the risk of breast cancer. They strengthen the teeth and bones and reduces the blood pressure. They are fruitful in losing weights although they contain fats, the reason is that they contain fiber and protein which may make one feel full for longer duration and thus help in lowering intake of other high calorie foods. They are also very helpful in preventing the formation of gallstone. We should promote the plantation of these fruits trees and we should protect these trees because we are consuming them in our daily life to full fill our daily needs. Our government should focus on the production of this fruit, where it can be grown easily and in return can earn big income. We are lacking good storage conditions, as dry fruits are not perishable, so these can be stored for long time and excess production can be exported.