The present invention relates generally to a plant growth media and more particularly to a process for using the plant growth media to control plant growth rates, to increase the germination rate of seeds and to increase the number of seeds that germinate.
Many food, flower and forest crops are first established as transplants grown from seed or vegetative tissue prior to being planted in an open field. The purpose of first establishing the crops as transplants is to enhance their survivability, to reproduce more uniform plants, and to promote early plant development under controlled environmental conditions. As used herein, a transplant is referred to as a plant first grown in one environment and then later removed or transferred elsewhere for further growth. Most transplants are grown in greenhouses or under other similarly controlled conditions. Some commercial crops, such as celery, are developed entirely from transplants.
When producing transplants, perhaps the most important objective is to grow a sturdy and healthy plant capable of surviving not only transportation but also relocation to a new environment, such as an open field. In most situations, it is advantageous to grow healthy plants as quickly as possibly. However, under some circumstances it is also desirable to slow the normal growth rate of the transplant. Growth rates are preferably controlled so that the plants are ready to be transplanted within a particular time frame. For instance, plant growth schedules may be adjusted to correspond to growing seasons, to fulfill a market shortage, to fulfill a particular customer's needs or even to have plants available on a continuous basis.
Currently, transplant producers are, in general, using two different methods to control and regulate plant growth. In one method, plant development is altered by changing the growing conditions of the plant. Specifically, the temperature, the supply of light, the amount of water or the amount of nutrients fed to the plant are varied depending upon the desired result. For instance, in order to retard plant growth, plants are typically sprayed with cold water, fed limited amounts of nutrients and/or exposed to limited amounts of light. However, such methods traumatize the plants making them weak and less durable. In fact, some plants never recover from the trauma and, if a food crop is involved, can result in a reduced yield.
Another method of altering plant growth is to spray the transplants with an organic compound. Such compounds have been used to primarily retard the growth rate of the plants. However, due to federal regulations, organic compounds cannot be used on all types of plants. Specifically, these compounds are not fit for human consumption and therefore have been banned from use on food crops.
As such, there currently exists a need for a product and a method that can be used to control the growth rate of plants, and specifically transplants. The present invention recognizes and addresses the above-described disadvantages and deficiencies of prior art methods. In very general terms, the present invention is directed to a plant growth media that can selectively be used to increase or retard plant growth rates while still producing healthy and viable plants. The plant growth media basically comprises a soil formulation mixed with different concentrations of a ureaformaldehyde foam. Depending upon the particular concentration, the ureaformaldehyde foam increases or decreases the growth rate of plants without any adverse side effects. Further, the soil compositions containing the ureaformaldehyde foam provide many other additional benefits and advantages as will be described hereinafter.
In the past, ureaformaldehyde compositions and various foaming compounds have been used in various plant related processes for various reasons. However, as will be evident, particular features and aspects of the present invention remain absent from the prior art.
One particular prior art method is disclosed in an article entitled "Ureafoam As An Amendment For Container Media of Croton" by Ben-Jaacov et al. The article is directed to the use of Hydrosoil, a ureafoam, as an amendment to a growth media. Specifically, the Hydrosoil was tested to determine its water holding capacity. In conclusion, the article states that the addition of Hydrosoil does not improve growth and only slightly reduced days to wilt.
A process and composition for conditioning soil by treating the soil with an iron salt and at least one polymer in the presence of a protein substance is disclosed in U.S. Pat. No. 4,575,391 to DeBoodt et al. The polymer can be a ureaformaldehyde resin. The mixture is preferably used in the form of an aqueous solution or dispersion which is sprayed over the surface of the soil in order to bind the soil particles together.
In U.S. Pat. No. 4,473,390 to Teufel, a soil product is disclosed made from straw coated with a water insoluble material. Examples of water insoluble materials include ureaformaldehyde resin, phenol formaldehyde resin and polyvinylacetate. The straw and material are mixed, formed into blocks, and then reduced to a usable particle soil like size. The soil product may be used alone or in combination with other materials such as natural soil. The soil product slowly decomposes over time and in some cases can provide a release of nutrients as it decomposes.
U.S. Pat. No. 3,812,619 to Wood et al. is directed to horticultural foam structures. The foam structures are prepared by reacting an isocyanate polyoxyethylene polyol reactant with large amounts of an aqueous reactant containing seeds or the like. Further, water soluble or water dispersible materials useful for seed germination and plant growth may be added to the aqueous reactant. The resultant foam structures can then be used as plant potting media, matrices for flower arrangements, or for supporting seedlings.
A plant substrate body is disclosed in U.S. Pat. No. 3,799,755 to Rack. The plant substrate body is made from peat and standard soil that has been dried and mixed with a liquid composition of reactants including a blowing agent which forms an elastic polyurethane foam. When the mixture is foamed, the peat and soil is organically bonded by the foam to form the substrate body. The foam can contain from about 20% to 60% of the peat and standard soil. The substrate body is for permanently supporting the growth of plant roots.
Other prior art methods directed to fertilizers and soil improving materials are disclosed in U.S. Pat. Nos. 3,373,009, 3,417,171, 3,705,794, 3,713,404, 4,190,428, and 4,411,683. In particular, solid control released ureaformaldehyde fertilizer compositions and other foamed, fertilizing containing compositions are disclosed. An aqueous solution containing a ureaformaldehyde precondensate for preventing soil erosion is disclosed in U.S. Pat. No. 4,743,288, while a composite foam plant growth medium including a water and soluble open-celled foamed polyurethane matrix having expanded cellular thermoplastic particles dispersed therein is disclosed in U.S. Pat. No. 3,798,836.
Thus, the prior art describes and discloses various fertilizer and soil agents. However, the prior art fails to disclose a method or soil amendment that can be used to effectively control the growth rate of plants. Further, the prior art fails to disclose a process for using a ureaformaldehyde foam for controlling plant growth rates, including its use for increasing germination rates and plant uniformity.