Method of accelerating the growth and development of trees and shrubs via enhanced root development
09723796 · 2017-08-08
Assignee
Inventors
Cpc classification
International classification
A01G9/20
HUMAN NECESSITIES
Abstract
A method and container for developing seedlings includes germinating the seeds and air pruning the seedlings to a depth of about 3 inches.
Claims
1. A method of facilitating air root pruning of seedlings, the method comprising: placing seeds on a surface of a soil-less growing medium, the growing medium comprising 35% to 40% composted rice hulls and 35% to 40% pine bark; germinating the seeds to obtain seedlings; subjecting the seedlings to a first air root pruning by growing the seedlings in a first bottomless container of 2½ inches to 3 inches deep; and after the first air root pruning, subjecting the seedlings to a second air root pruning by growing the seedlings in a second bottomless container of 3 inches to 4¼ inches deep.
2. The method according to claim 1, wherein the seedlings are transplanted between the first air root pruning and the second air root pruning.
3. The method according to claim 1, wherein the growing medium provides a 35% air space.
4. The method according to claim 1, wherein the air root pruning of the roots of the seedlings is performed by the growing medium being in one or more containers having an open bottom, the one or more containers adapted to be set on a mesh support.
5. The method according to claim 4, wherein the open bottom and mesh support are configured to expose to air at least some roots of the seedlings growing in the one or more containers.
6. The method according to claim 1, wherein the first bottomless container and the second bottomless container are placed at a height of between 30 and 36 inches above the floor.
7. The method according to claim 1, wherein the seeds are seeds of trees.
8. A method of developing seedlings with enhanced roots, comprising: germinating seeds on a surface of a growing medium to obtain seedlings; wherein the growing medium is in a bottomless container with a depth of 2½ inches to 3 inches; and subjecting the roots of the seedlings to a first air pruning at a root depth of 2½ inches to 3 inches.
9. The method according to claim 8, wherein the growing medium comprises 35% to 40% composted rice hulls, 35% to 40% pine bark, and 20% sand.
10. The method according to claim 9, wherein the growing medium comprises 10% composted manure.
11. The method according to claim 8, further comprising stratifying the seeds on the growing medium at 32 degrees F. prior to the seeds germinating.
12. The method according to claim 8, wherein the seedlings are transplanted after the first air pruning to a bottomless container in which the growing medium is placed to a depth of 3 inches to 4¼ inches.
13. The method according to claim 12, wherein the roots of the transplanted seedlings are subjected to a second air pruning at a root depth of 3 inches to 4¼ inches.
14. The method according to claim 8, wherein the seedlings are transplanted after the first air pruning to a bottomless container in which the growing medium is placed to a depth of 3 inches to 5½ inches.
15. The method according to claim 14, wherein the roots of the transplanted seedlings are subjected to a second air pruning at a root depth of 3 inches to 5½ inches.
16. A method of developing seedlings, comprising the steps of: placing a first soil-less growing medium in a first bottomless container to a depth of 2½ inches to 3 inches; placing seeds on the growing medium; germinating the seeds on the surface of the growing medium to obtain seedlings; and allowing roots of the seedlings to undergo a first air pruning at a root depth of 2½ inches to 3 inches.
17. The method according to claim 16, further comprising: transplanting the air-pruned seedlings to a second bottomless container, wherein the second bottomless container is provided with a second soil-less growing medium to a depth of 3 inches to 4¼ inches; and allowing the roots of the seedlings to undergo a second root air pruning at a root depth of 3 inches to 4¼ inches.
18. The method according to claim 16, wherein the air root pruning of the roots of the seedlings is performed by the growing medium being in one or more containers having an open bottom, the one or more containers adapted to be set on a mesh support.
19. The method according to claim 18, wherein the open bottom and mesh support are configured to expose to air at least some roots of the seedlings growing in the one or more containers.
20. The method according to claim 17 wherein the first bottomless container and the second bottomless container are placed at a height of between 30 and 36 inches above the floor.
Description
BRIEF DESCRIPTION OF THE FIGURES
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DETAILED DESCRIPTION OF THE INVENTION
(38) The method of the present invention involves consideration of seed selection, including seed origin (provenance, density, and size). It further involves consideration of seed handling including stratification, timing of germination to extend growing season, technique (depth) of seeding. It further involves air pruning, preferably in two steps using air as a means of root pruning to enhance the development of a dense fibrous root mass. It further involves gradation for uniformity of stock and to reduce transplanting losses. Lastly, the method involves selection of growing media, including fertilizer, consideration of air space, wetting agents, and components. The method of the present invention accelerates rate of growth, and induces early flowering and fruiting.
(39) Seed selection is an important component in the acceleration of tree growth. Special attention is provided to assure seed is selected from superior individual parents, showing outstanding phenotype, typical of the particular specie or variety of tree. Attention also must be focused on the climate zone of origin, including attitude and locations within its native geographical range, normally referred to as “provenance”. Within a given provenance, seed is selected based on environmental conditions of the final location. It is desirable to select seed from the same species growing in the same environmental conditions, e.g., a flood plain or an upland site. Seed is collected site specific. These different types of seed are referred to as ecotypes. Proper selection results in tree improvement, superior adaption to planting sites all of which add to economic and aesthetic value.
(40) Seed handling is also an important component in the acceleration of tree growth. Collected seed are processed by cleaning out any foreign materials. They are then processed through an aspirator to separate out the heaviest individual seed. Density is the most important factor in germination capacity of any seed, and survival of the seedling. Density is a measure of the stored food reserve. After the heaviest seed are selected they are then processed through a sieve which grades them by size, e.g. three (3) or four (4) different sizes. Only the largest, heaviest seed are used. Since these factors (weight, size, and density) are genetic in nature these processes have definite effects on the genetic improvement of the progeny.
(41) Seed stratification and timing are also important in the acceleration of tree growth. The length of time required for stratification is predetermined so germination can start (For example February 1st.) Thus the seed must be handled in such a manor that all stratification requirements are satisfied prior to February 1st. Thus, for example, a seed requiring ninety (90) days of cold stratification would have to be placed in our cold storage November 1st, so that it could be germinated by February 1st. As shown in
(42) The timing of the above steps in the method is based on having the seedlings processed through termination, Step I root pruning, grading, and Step II transplanting, so they are ready for planting outdoors by the frost free date (approximately May 10 in Missouri). This gives the seedlings the maximum growing period until the first fall frost, approximately 210 growing days. A time sequence might be: February 1 st—start germination in greenhouse at a temperature of between 68° F. and 72° F. for about thirty days, as shown in
(43) As described above, the seeding is done by placing seed on a bottomless mesh seed flat. While seed flats measuring 18½ inches×14½ inches×2½ inches deep with mesh spacing of ⅜ inches have been used satisfactorily, as shown in
(44) There is a universal problem of proper nutrient uptake by woody plants in artificial (soil-less) growing media. Through analysis of the media compared to the analysis of the leaves from plants grown in media for Quercus bicolor—Swamp White Oak, the inventors have determined that the addition of 10% composted manure to the growing media of composted rice hulls, pine bark, and sand plus slow release fertilizer and minor trace nutrient improves the nutrient level in the plants, with most of the nutrients moving from a low interpretation in the soil medium to a desired level within the plant resulting in maximum plant growth and performance.
(45) The addition of manure promotes the development of a balanced biological atmosphere within the growing media, promoting the growth of numerous beneficial organisms. These organisms help promote the development of desirable soil fauna that break down organic matter releasing essential bi-products (enzymes etc.) that benefit the plant by enabling uptake of nutrients that are present in the media here-to-fore but not available in a form the plant can absorb. This resulted in a reduced fertilizer rate of 50%, resulting in substantial cost savings. Also there is less impact on the environment because of fewer nutrients leaching and run off while still achieving maximum plant growth.
(46) The inventors have also discovered that the incorporation of ¾ of a pound of Talstar systemic insecticide in each cubic yard of growing media trans locates throughout the plants system, helps plants grown in the media to ward off attack by a number of undesirable insect pests including but not limited to Japanese beetle.
(47) As shown in
(48) This root pruning preferably occurs at about 2½-3 inches. Extensive research conducted by the inventors has established that the ideal depth for the first air root pruning (
(49) As shown in
(50) The inventors' research also determined that the optimum size of the container for Step II is a bottomless tree band measuring 3 9/16 inches×3 9/16 inches×4¼ inches deep (see
(51) TABLE-US-00001 BOTTOMLESS BANDS TESTED Band Size 1¼ × 1¼ × 3¾ 2½ × 2½ × 3¾ 2¾ × 2¾ × 5½ 3 9/16 × 3 9/16 × 4¼
(52) This shallow air pruning is unique to the method of this invention, and enhances the root system resulting in the production of a superior plant that can survive, perform, and grow faster under every condition tested. Prior root pruning methods typically prune at least 5 inches or more. The shallower air pruning of the present invention induces rapid lateral root development high on the tree root collar, where most desirable, and where their function to the welfare of the tree will be best served.
(53) The inventors have also tested various bench heights (i.e., the height from the greenhouse floor to the wire mesh supports) under a strictly controlled greenhouse environment, for both the first and second air root pruning steps. Heights of 12, 18, 24, 30, and 36 inches were all carefully tested. While there was little differences in the 30 and 36 inches bench heights, both were far superior in air flow and subsequent root pruning to 12, 18, and 24 inches. As a result, the inventors have determined that balancing effectiveness of root pruning versus construction and installation costs, and ergonomic considerations, a height of 30 inches is optimum.
(54) The seedlings are graded to identify the genetically superior individuals. Experience and research has proven that selecting the largest seedlings after their first flush of growth identifies those individuals that will remain dominant, grow faster, and exhibit genetic superiority when grown to a larger size and eventually out planted. When grading, particular attention is given to the combination of height, caliper, and root development. On most species of woody plants the top 50% are retained and transplanted and the remaining plants are discarded. This grading process has proven to be a significant step in tree improvement.
(55) The graded seedlings are then transplanted into a bottomless band measuring 2⅞″×2⅞″×3¾″ in depth. (This short band gives improved growth and improves the root distribution in the production container.) The transplanted seedlings in the bottomless bands are placed on raised bottomless benches to promote additional air pruning, which occurs on secondary lateral roots further enhancing the development of a shallow dense root mass with many root tips. The first two steps are timed so the plants are ready to be transplanted outside in the container production area immediately after the last frost date (early May in Missouri) to avoid late frosts, but timed to maximize the growing season. It is also desirable to coordinate transplantation outside with the tree's setting a temporary terminal bud. When this occurs, photosynthate is trans-located from the leaves down to the roots. This promotes very active root development, and thus quick establishment in the container resulting in accelerated growth.
(56) As shown in
(57) As shown in
(58) The trees produced with the method of this invention grow an average of three times faster than conventionally grown seedlings. As show in
(59) Most varieties of trees grown under this production system have exhibited early flowering and fruiting characteristics. Examples are Swamp White Oak (Quercus bicolor) and Bur Oak (Quercus macrocarpa). It is generally accepted in the literature that these species begin flowering and fruiting at about 20 to 25 years of age. See, Schopmeyer, Seeds of Wood Plants in the United States, Agriculture Handbook No. 450, Forest Service, U.S. Department of Agriculture, Washington, D.C., Table 2 (1974), incorporated herein by reference. However, as shown in
(60) Specific differences between the method of the present invention, and prior methods of tree production include: (1) the shallow depth of air pruning (about 2½″); (2) seed grading to select genetically superior seeds; (3) transplantation after the first root pruning to bottomless bands to further increase root mass, as shown in
(61) The inventors have propagated approximately 750,000 containerized oak and nut tree seedlings per year, many of which have been out-planted on abandoned mine lands, old wetland sites and fields in central and western Missouri. First-year establishment success for containerized seedlings is approximately twice the success of bare-root seedlings in side-by-side field trials. Greatest mortality resulted from excessive competing vegetation and rodent damage in winter. Tap-rooted hardwoods such as oak, hickory, and walnut responded well to air-pruning, which resulted from using bottomless containers. Seedlings were propagated and placed upon a raised, welded hog or cattle panel, with four-inch squares, protected from squirrels by a wood frame and chicken wire.
(62) Qualitative observation of establishment success suggests a first-season survival rate of 90 percent for air-pruned bur oak and pecan grown in half-gallon bottomless containers. This compares to 40 to 50 percent survival of year old bare-root stock grown at a local nursery. These were side-by-side trials of seedlings planted in prepared rows of prairie soils in Conservation Reserve Program (CRP) crop fields in western Missouri. Rows were set at 15-foot centers, disked, and planted by hand. Containerized seedlings were planted in fall, and bare-root seedlings were planted in spring. Success rates were slightly higher in very fine sandy loam soils mapped as Bates loam, (2 to 5 percent slopes, fine-loamy, siliceous, therrvic (Typic Argiudolls) compared to silty clay soils mapped as Kenoma (2 to 5 percent slopes, fine, montmorillinitic, thermic Vertic Argiudolls) (USDA 1995). Competition became intense in mid-summer as late-season weeds such as common and giant ragweed; cocklebur and begger ticks germinated from the old-field seedbank. The rows were mowed in July to prevent shading of the seedlings.
(63) A second test plot was established on rough-graded, neutral mine spoils (silty clay texture with 15 percent shale channers, 5 percent sandstone pebbles and few sandstone cobbles) in western Missouri. Establishment success in the first season was approximately 75 percent for containerized bur oak and pecan compared to 30 percent for bare-root seedlings. Compaction was minimal since all grading was performed by a D-3 dozer knocking the tops off the spoil-ridges, pushing the fill into the valleys between ridges. Wind-disseminated species, particularly broomsedge, slowly colonized the plots, competing with the seedlings. Adjacent mine spoils were heavily vegetated, enabling deer to browse the plot undisturbed.
(64) A third test plot was established in central Missouri on loess-derived forest soils that had been cleared in the 19th century, farmed and planted to tall fescue in recent decades. In places, much of the A horizon had been eroded and mixed by plowing into the E horizon. The soils were classified as eroded Winfield silt roam (fine-silty mixed mesic. Typic Hapludalfs) (USDA 1994). Fescue sod was removed with a heavy hoe around each seedling to reduce competition at the time of establishment. Spraying also is effective; but the seedlings should be dormant. First-year success rates for containerized bur and northern red oak were 90 percent compared to 25 percent for bare-root.
(65) The following table shows a hypothetical cost/benefit analysis of plants grown in accordance with the principles of the present invention versus conventional bare root plants.
(66) TABLE-US-00002 HYPOTHETICAL COST/BENEFIT, SURVIVAL AND ENHANCED GROWTH RATE COMPARISON BETWEEN SEEDLINGS GROWN IN ACCORDANCE WITH THE PRESENT INVENTION AND BARE ROOT SEEDLING OAK TREES BARE ROOT BARE ROOT BARE ROOT INVENTION INVENTION DESCRIPTION 1 2 3 (UPLAND) (DOWNLAND) SURVIVAL 85% 50% 30% 90% 90% RATE Cost per 1000 $500 $500 $500 $7500 $7500 planted Survival per 850 500 300 900 900 1000 planted Years of fruit 0 0 0 10 10 production Pounds of 0 0 0 36,000 36.000 fruit production Carbohydrate 0 0 0 14,398 14,398 value (based on corn) Average dhb 16 inches 16 inches 16 inches 20 inches 24 inches Wood fiber 81 brd ft. 81 brd ft. 81 brd ft. 170 brd ft. 260 brd ft. yield per tree Total Volume 68,850 40,500 24,300 153,000 234,000 of wood fiber Value per $20,655 $12,150 $7,290 $45,900 $70,200 1000 planted @ 0.30/brd ft. Value of early 0 0 0 $14,398 $14,398 fruiting Total value $20,655 $12,150 $7,290 $60,298 $84,598 Cost $500 $500 $500 $7500 $7500 Gross Return $20,155 $11,650 $6,790 $52,798 $77,098