Back to May 2015

Pecan Orchard Establishment

Planting seed in place. Pecan orchards are difficult to establish by planting seed because it requires individual tree care for tree selection, irrigation, weed control and unwanted tree removal. All of which occurs over a long three to five year period of time. Though seemingly less costly, it is, however, the most expensive system for planting a pecan orchard — because of the three to five years it takes to get the trees up and growing. It is difficult to control weeds on these small trees, which are far apart.

Grow your own nursery seedlings or grafted trees. Some growers start by growing pecan nursery trees and planting them to develop their own orchard. The decision to grow nursery trees or purchase trees depends on the individual. Nursery trees are easy to grow, but very difficult to dig after 3 years. Growers with container nursery skills can grow their own trees with good seedling trees produced in 2 or 3 years. The trees can be patch bud grafted in the container before transplanting to the orchard or the seedling trees can be transplanted and four flap or inlay bark grafted 2 or 3 years later in the orchard. The delay in grafting gives a grower 2 or 3 years to evaluate potential new varieties recently available. Three or more years are needed to successfully graft all the trees. These failed or delayed grafting efforts result in non-uniform tree size and post-graft after-care, which is extra work or a problem. Though seemingly less costly, the grow-your-own nursery tree system takes longer time and more individual tree care, which is frequently neglected or put off until it is too late. For this reason, growers should not attempt to establish more than 10 acres with this system. There are many examples of orchards that have a significant percentage of inferior seedling trees because they were not grafted.

Planting grafted nursery trees. This is the most common system used in the industry because it is fast, uniform, and with less effort and worry. It is also the least costly and comes into production fastest. Grafted nursery trees are in the adult, not juvenile, phase of growth and require modified central leader training. This requires knowledge and practice; otherwise, the trees will grow as an adult with numerous scaffold limbs too close to the ground. These multi-limb trees have problems with tree crowding, tractor passage and shaker attachment, but with more pecans in year 5, 6 and 7. However, with good establishment management and central leader training, grafted nursery trees can come into full production in seven years or less, depending on the variety.

Transplanting via tree spades. In the irrigated West and to a lesser degree in Central Texas, some pecan growers intentionally plant trees too close and move every other row or tree after 3 to 5 years. The ultra closely planted trees are easier to manage when young. The trees are later moved only a short distance by using a mechanical tree spade. The soil needs to be the same texture at both locations. Frequent tank watering or flood irrigation will be needed at the new tree site. This system is commonly called “orchard expansion”. If for unexpected reasons the closely spaced trees are not moved, excessive tree crowding will result.

Production age for new orchards. Some orchards require 10 to 12 years to come into production while others can bear economic crops in less than 7 years. The determining factor is the cost of harvesting — when the young tree crop income is greater than the cost of harvesting, the trees are considered in production. Full production for mature trees for a specific region can be 500, 750, 1,000 or 1,500 pounds per acre and will depend on soil, water, variety, spacing and quality of management.

Essential Factors Needed for Pecan Orchard Establishment

Orchard size and financing. A cost of $2 to $4,000 per acre, not including the cost of the land and irrigation, is required for orchard establishment. There are in general 3 orchard sizes: small family orchards with no labor with 1 to 100 acres; moderate size orchards of 100 to 500 acres with owners providing management and limited labor and equipment; and corporate orchards of 500+ acres with hired management, extensive labor, and equipment.

Time has value and 7 to 10+ years are required for investment dollars without return.

Knowledge or skills with information gathering, budgeting, record keeping, laws, labor, equipment, horticulture, irrigation, weed control, other cash flow crops, wildlife and more can influence orchard establishment. However, there are many non-formally trained individuals who have the gift of “knowing when a tree is healthy or not healthy” and they can establish a pecan orchard fast and correctly. Information gathering is a vital tool that should be used fully. The Texas Pecan Shortcourse, county Extension agents, Texas A&M pecan specialists, USDA Natural Resources and Conservation Service, fellow pecan growers, neighbors, and more need to be utilized in obtaining information on how to grow pecans. The day of “doing your own thing” is history. Pecan orchard establishment is expensive and requires time; bringing trees into production fast and correctly is essential. All growers differ in their available time, financing, knowledge, experience, equipment, climate, soil, varieties, etc; therefore, they have from the very beginning been open-minded and cooperative with each and every pecan grower. This free exchange of ideas and information needs to continue and be utilized to its full potential.

Climate. Pecans need to be grown in a climate with 400 hours of winter chilling, and 150 growing days to flower and ripen the crop. Early fall and late spring freezes are a concern.

Soil. Pecans need deep well-drained soil. A wide range of soil pH is tolerated. The USDA NRCS Soil Survey Maps are very helpful in understanding pecan orchard soil.

Irrigation. Newly planted pecan trees will need moist, not wet, soil that never goes dry. Tank watering for year 1 and 2 can deliver water when and where and the correct amount. All forms of irrigation plus rainfall improve young tree growth. Never saturate the soil and never allow the root zone to become dry. Irrigation water needs to be salt-free; water with an SAR of less than 4 is ideal, an SAR of less than 7 can be managed if salt-free water or rainfall can leach the sodium out of the soil. Soil with an SAR of more than 8 should not be planted with pecans.

Nitrogen. Once a new root system is established, frequent small nitrogen fertilization stimulates rapid shoot growth. Ground-applied nitrogen should be stopped in mid-June to ensure soil depletion of N in the fall to prevent late-season growth and potential freeze injury or death. The N rate for injection into a drip irrigation should never be more than one-fourth the ground recommended rate. Foliar N in combination with zinc can be applied until mid-August and the liquid 32 percent N should never be applied at a rate higher than 1 percent to prevent foliage burn.

Foliar zinc. Each spring at bud break foliar zinc as zinc sulfate powder or zinc nitrate liquid should begin. Zinc + N foliar sprays should be applied as long as new growth is being made. It is common for growers to spray zinc + N every 2 weeks; some growers spray weekly. Ground-applied zinc is not effective. Zinc chelates, zinc chloride or zinc oxide are not effective on pecans.

Weed control. Glyphosate post-emergence contact herbicide is used to kill most grass and broadleaf weeds in pecans. In recent years, glyphosate-resistant pigweed has become a major issue in pecan orchards. In 2015, several ag chemical companies will be marketing several different and new combinations of glyphosate + 2,4-D herbicides; extreme care must be taken to prevent 2,4-D products from contacting any live growth on young pecan trees. Any air movement could bring 2,4-D in contact with new growth with subsequent tree damage or death. Grow tubes are essential in protecting young pecan tree trunks from damage by all contact herbicides. Shallow tillage is a good tool in controlling weeds during orchard establishment, however, it cannot be used in regions that have frequent rains. Weed barriers can be used on plantings of limited trees, but it is too expensive for plantings over one acre in size. Glufosinate, though different from glyphosate, has also failed to kill glyphosate-resistant pigweed at the A&M pecan orchard. This resistant pigweed is a major issue and there is not a reliable solution at this date, though the major ag chemical companies are working hard to discover a product or combination of products that will kill resistant pigweed. Frequent rains increase the difficulty of controlling weeds, regardless of the system. Low mowed sod, though competitive for soil moisture and soil nitrogen, may be needed in combination with weed barriers at the tree when resistant pigweed is well established in an orchard. There are additional weeds developing resistance to glyphosate, thus chemical weed control could become more difficult.

Young Pecan Tree Training

Fast growth is needed to properly train young pecan trees. If the tree is not growing fast, do not attempt to train the tree by repeated pruning. Fast tree growth is obtained by having and/or following the above-discussed factors. These factors are more important than pruning a young tree.

Modified central leader tree training is the system used to develop the adult growth into a central leader tree. The tree is cut back one-half at planting. One shoot is selected as the central leader within the top 6 inches of the cut back trunk; all other shoots are rubbed off when they are short and easy to pop off by hand. The selected shoot should make significant growth the first year. If less than 12 inches of growth on the central leader is obtained, some type of management error has occurred and extensive pruning of short shoots should not be used. When management is less than ideal, just keeping the first-year trees alive is good. The most common cause of no or limited growth the first year is the failure of new roots to develop early in the growing season.

Second-year central leader tree training. Select the strongest shoot as the central leader and cut it back one half in the dormant season before growth starts. The one-half cut-back point is only on the one-year growth from last season. When new shoot growth begins, select the strongest new shoot and hand remove all the other shoots within 6 inches of the cut-back point. This hand-selected shoot should make outstanding growth for the entire growing season. This selected central leader has been known to grow 12 feet in one year. Do not remove any side shoots from the young tree unless they are 1 inch in diameter. If central leader training was not practiced the first year, remove all “V” trunks so that the tree will have only one central leader. Do cut back on the strongest shoot that is only one year old.

Third-year central leader tree training. Repeat the same training and pruning technique used in year two. Cut back and select the central leader. As new shoots grow at the cut-back point, remove all shoots except the selected central leader. On the trunk, do not remove side shoots until they are 1 inch in diameter because they produce the food that feeds the new central leader growth. Scaffold limbs can develop 5 feet above the ground. Do not allow scaffold limbs to develop on the lower 5 foot of tree trunk. Should “V” trunks occur, remove one so that the tree has only one central leader. Thin out or prune out scaffold limbs which are stacked immediately above each other. Thin out scaffold limbs that are opposite each other on the trunk.

Tip or Suggestions When Training Young Pecan Trees

The first year is for new root growth, so do not become too anxious for fast shoot growth.

Heavy cut-back pruning always stimulates rapid compensatory growth on a few shoots.

Tip pruning removes the apical dominance of the terminal bud and allows many lateral shoots.

Always leave a short collar on the trunk when a shoot is pruned off. This collar is the passageway for food and water above and below the cut.

Pruning and tree training can be done any day of the year, not just in the winter dormant period.

It is better to prune while the shoots are small, rather than later when major cuts will be needed.

Author Photo

George Ray McEachern

George Ray McEachern is a professor of Horticulture, Texas A&M University, College Station, Texas.