Pecans thrive in regions with long summers and prefer a moderate climate with temperatures ranging between 24 - 30°C. They require some winter chilling to set fruit, but they are sensitive to frosts during the growing season. Altitude preferences for pecans vary, but it is important to note that different cultivars have different requirements. Adequate pollination occurs in areas with lower humidity, although pecans naturally grow in high humidity regions. Soil moisture is crucial for pecans, and they prefer fertile, well-drained soils with good water holding capacity. Pecans can tolerate a pH range of 6 - 8 but do not grow well in saline soils.
Pecan
The pecan (Carya illinoensis) is a nut-producing tree native to North America. It belongs to the same botanical family as the walnut and shares the same genus as the hickory. Pecans are long-lived trees that can reach heights of up to 100 meters. They prefer long summers and well-drained, fertile soils, and are known for their delicious and nutritious nuts, which are high in fat, protein, and various minerals.
Carya illinoensis
United States
The pecan tree, scientifically known as Carya illinoensis, is a member of the JUGLANDACEAE family. It is closely related to the walnut and hickory trees and shares the same genus with the hickory. Native to North America, the pecan tree is also cultivated in Australia as a commercial crop since the early 1970s. Pecans are known for their longevity, with some trees reaching heights of up to 100 meters. They typically start producing nuts around 6-7 years of age and reach maturity between 15-20 years. A mature pecan tree can yield up to 50 kg of nuts, although the average production ranges from 20-30 kg. In terms of nutritional composition, per 100 grams of edible portion, pecans contain approximately 3.4% water, 687 calories of energy, 14.6 grams of carbohydrates, 71.2 grams of fat, 9.2 grams of protein, 1.6 grams of ash, 73 mg of calcium, 603 mg of potassium, trace amounts of sodium, 142 mg of magnesium, 2.4 mg of iron, 289 mg of phosphorous, 130 I.U. of vitamin A, 0.86 mg of thiamin, 0.13 mg of riboflavin, 0.9 mg of niacin, and 0.9 mg of ascorbic acid. The digestion time for pecans is approximately 2.75 hours. Pecan trees thrive in regions with long summers and prefer temperatures ranging from 24-30 degrees Celsius. Adequate winter chilling is necessary for fruit set, but the trees are sensitive to frosts during the growing season. Different cultivars have varying requirements for the length of the growing season, so choosing the right variety is crucial. While pecans naturally grow in high humidity areas, it has been observed that pollination is more successful in lower humidity conditions. The trees require ample soil moisture, but excessive rainfall or severe weather conditions during flowering and harvest times can negatively impact production. Pecans can be grown in a wide range of soils as long as they are fertile, well-drained, and have good water-holding capacity. Neutral soils with a pH range of 6-8 are preferable, while saline soils are unsuitable for pecan cultivation. The pecan tree bears both male and female flowers on the same tree and is primarily wind-pollinated. While it is self-fertile, better-quality nuts are obtained through cross-pollination. Planting different cultivars together ensures adequate pollination. Commonly, pecans are budded or grafted onto seedling rootstocks, with Riverside and Apache being popular choices. Orchard planting spacing can vary, with traditional spacing at 15 meters x 15 meters and newer cultivars being planted at 5 meters x 10 meters or 7.5 meters x 7.5 meters. Pruning pecan trees involves the removal of weak, dead, or crossing branches. Excessive pruning can lead to reduced yields since pecans bear fruit on new growth. Older trees require some pruning to stimulate growth and maintain productivity. In Australia, pecan trees are relatively resistant to pests and diseases. However, parrots and cockatoos can pose a potential problem. Cultivars There are more than 500 pecan cultivars, although many are no longer commercially grown. Some notable cultivars include:
- Fertile and well-drained soil - Good water holding capacity - Neutral soils preferred, but pH range of 6 - 8 tolerated - Will not grow on saline soils
Family: JUGLANDACEAE
The pecan belongs to the same botanical family as the walnut and also belongs to the same genus as the hickory, with which it is cross fertile. It is a native of North America, and although it was introduced to Australia many years ago, it only became a commercial crop in the early 1970's. Pecans are long - lived trees and grow as tall as 100 m. They begin to bear nuts at 6 - 7 years of age and reach maturity at 15 - 20 years. A mature tree can produce up to 50 kg of nuts, but 20 - 30 kg is more usual.
Nutritional composition of the pecan per 100 grams of edible portion is: Water - 3.4%, Energy - 687 calories, Carbohydrate - 14.6 g, Fat - 71.2 g, Protein - 9.2 g, Ash - 1.6 g, Calcium - 73 mg, Potassium - 603 mg, Sodium - trace, Magnesium - 142 mg, Iron - 2.4 mg, Phosphorous - 289 mg, Vitamin A - 130 I.U., Thiamin - 0.86 mg, Riboflavin - 0.13 mg, Niacin - 0.9 mg, Ascorbic acid - 0.9 mgs and the digestion time is 2.75 hours.
Pecans prefer long summers and appear to grow best where the summer temperature range is within 24 - 30oC, although no extensive research has been carried out on temperature require-ments. Some winter chilling is necessary to set fruit but the pecan is sensitive to frosts during the growing season. Different cultivars require different lengths of growing season, so selection of a suitable variety is important. In areas where the growing season is 230 days or more, choice of cultivars is unlimited. The pecan grows naturally in areas of high humidity, but it has been found that pollination is better where humidity is lower. Pecans need an abundance of soil moisture, but rainfall at flowering and harvest times can lower production, as can wind or hail storms.
Pecans will grow on a wide range of soils, providing they are fertile and well drained, with a good water holding capacity. Neutral soils are preferable, but a pH range of 6 - 8 will be tolerated. They will not grow on soils that are at all saline.
The pecan has both male and female flowers on the same tree and is wind pollinated. It is also self - fertile, but better quality nuts are produced when cross - pollinated. Different cultivars should be planted together to ensure adequate pollination.
Pecans are usually budded or grafted onto seedling rootstock, the most popular being Riverside and Apache.
Traditionally, orchards were planted at 15 m x 15 m although with newer cultivars, 5 m x 10 m or 7.5 m x 7.5 m is the more usual spacing.
Pruning consists of removing weak, dead or broken branches, and branches that cross or are otherwise wayward. The tree produces fruit on its new growth, so extensive pruning will result in lower yields. In older trees, some pruning will be required to stimulate growth and maintain production.
The pecan is susceptible to very few pests and diseases in Australia as yet, the main problem being parrots and cockatoos.
Cultivars
There are over 500 cultivars of pecan in existence, although many of these are no longer commercially grown. Some of the more important ones are: