Pecan

Pecan, Carya illinoinensis, is a large deciduous tree in the family Juglandaceae grown for its edible seeds (nuts). The pecan tree has a thick gray-brown trunk which can reach 2 m (6.6 ft) in diameter and a rounded canopy that spreads . The bark is ridged and has a scaly appearance. The twigs of the tree are red-brown in color and the foliage is dark green. The leaves are pinnately divided and composed of 9–17 oblong-lanceolate leaflets. Each leaflet has as serrated margin and a downward curving tip. The tree produces separate male and female catkins with the male producing pollen and the female developing into the fruit. The male catkin is slender and pendulous, measuring 22–50 cm (8.7–19.7 in) in length and the female catkins are much smaller and possess 3–6 flowers in a cluster. The fruit is an oval–oblong drupe containing a single seed surrounded by a thin shell. The outer husk (shuck) is green, turning brown-black when mature at which point it also splits open to release the nut. The edible kernel of the nut is light brown in color and ridged longitudinally. Pecan trees can reach a height of 40–50 m (131–164 ft) and can live for several hundred years in a wild state. Commercial trees usually have an economic lifespan of approximately 25 years. Pecan originates from the North America, specifically, the South.


Pecan nuts are consumed fresh or after roasting as a snack food or may be used as an ingredient in baked goods or confection


Basic requirements Pecan trees have a high water requirement and within their native range they are found growing in deep soils where their extensive roots can reach the water table or along river banks or streams. Pecan trees thrive in areas with long hot summers and cool winters. Trees can be grown in a range of soils but will grow optimally in a deep, well draining clay loam or sandy loam with a pH 6.0–7.5. Growing multiple pecan trees requires a great deal of space as the trees can reach a very large size. Propagation Pecan trees can be propagated from nuts or by budding or grafting. Nuts for propagation should be collected in the Fall from trees which gave good fill. The seeds require stratification prior to planting. Stratification is the name given to a cold treatment which breaks the dormancy of the seed, speeding the germination process. Nuts are stratified at 2–5°C (35.6–41°F) for a period of 3- to 90 days and then incubated at room temperature. Nuts should be soaked in water for 24 hours prior to the treatment and kept moist throughout by mixing the nuts on moist vermiculite. The nuts can be planted outdoors in late winter if they are planted in place. if growing the seedlings in containers it is best to wait to plant until all threat of frost has passed. Seedling or grafted trees should be planted in full sun to part shade although trees are sensitive to shading and care should be exercised to ensure that the trees are not too shaded. Trees should be spaced 9–10 m (30–35 ft) apart General care and maintenance Newly planted trees must be supplied with adequate moisture to meet their growing requirements in the first few years following planting. Trees must be supplied with 10 to 15 gallons of water weekly. This water can come from rainfall, irrigation, or a combination of both. Fertilization rates should ideally be based on the results of a soil test prior to planting but generally, 4 lbs of a complete fertilizer should be applied in a circular area around the base of the tree measuring 25 square feet. Fertilizer should never be placed directly in the planting hole as it can cause damage to the tree roots. A subsequent similar application in the summer should be enough to meet the growth requirements of the tree. The following year, apply 4 lbs of complete fertilizer per inch of tree diameter. Fertilizer should not be placed within 30.5 cm (12 in) of the trees trunk. Harvesting Pecans should be harvested as soon as the nuts have reached maturity, when the shuck has lost its green color and has started to split. in commercial plantations, hydraulic shakers may be used to dislodge the nuts from the tree.


Anderson, P. C. & Crocker, T. E. The Pecan tree. University of Florida IFAS Extension. Available at: https://edis.ifas.ufl.edu/pdffiles/HS/HS22900.pdf. [Accessed 26 March 15]. Free to access. CABI Crop Protection Compendium. (2008). Carya illinoinensis (pecan) datasheet. Available at: http://www.cabi.org/cpc/datasheet/17234. [Accessed 26 March 15]. Paid subscription required. Carroll, B. Starting pecan trees. Oklahoma Cooperative Extension Service. Available at: http://pods.dasnr.okstate.edu/docushare/dsweb/Get/Document-1012/F-6207web.pdf. [Accessed 26 March 15]. Free to access. Polomsky, B. & Shaughnessy, D. (1999). Pecan planting and fertilization. Clemson Cooperative Extension. Available at: http://www.clemson.edu/extension/hgic/plants/vegetables/tree_fruits_nuts/hgic1356.html. [Accessed 26 March 15]. Free to access. Teviotdale, B. L., Michailides, T. J. & Pscheidt, J. W. (eds) (2002). Compendium of Nut Crop Diseases in Temperate Zones. American Phytopathological Society Press. Available at: http://www.apsnet.org/apsstore/shopapspress/Pages/42848.aspx. Available for purchase from APS Press.