Patent Application
20080115411
The invention relates generally to weed control, and more particularly to a weed control system that promotes weed seed germination and subsequently kills the weed seedlings.
Invasive exotic plants are a large problem in the United States as they cause billions of dollars in damages each year. The control of exotic species is a major challenge to biologists and a major drain on the resources of land-owners. The most effective way to control weed infestations is to aggressively fight small infestations as they are discovered so that the weed can not become widely established on a property. Small infestations usually occur along roadsides, trailheads, and parking areas where seeds are transported by the undercarriage and tires of vehicles. Small infestations also occur along the leading edge of large infestations. Many weed species greatly reduce the diversity of local flora occurring in a given location.
When landowners and land managers observe new weed infestations on their properties they initiate activities designed to control the spread of the weed and to eradicate it. These activities may consist of hand pulling the weeds, mowing the flowers off the weeds, or spraying the weeds with herbicides. However, the control of weed infestations using herbicide applications also reduces flora diversity because non-target plants are killed along with the undesirable weed. Herbicide application to a given area is imprecise because wind tends to blow the herbicide off of the targeted area and into non-target areas where the vegetation may be sensitive to the herbicide.
Using current weed control methodologies, eradication of weeds in infested areas may take years of persistent effort because seeds remaining in the soil or on the soil surface continue to germinate after the adult plants are killed. Seeds are often abundant because they have accumulated at the start of the infestation until the initiation of a management action. Killing all of the seedlings by a method such as hand pulling is difficult and labor intensive.
One exotic, invasive, and pervasive weed of great concern is Centaurea maculosa (or “spotted knapweed” as it is typically called). Spotted knapweed originated from Eurasia, but now infests grasslands, rangelands, areas recently burned by forest fires, and areas disturbed by construction activities such as road building across the United States. Areas heavily infested with knapweed suffer from reduced native plant productivity as biodiversity can be reduced by more than 90%. Knapweed avoids competition with con-specific plants by secreting a compound known as racemic catechin which inhibits the germination of knapweed seeds. Germination inhibition allows knapweed plants to self-regulate the density of knapweed plants in an area. That is, knapweed seeds that would otherwise sprout and have to compete with adult plants, wait in the soil in a “seed bank” until the adult knapweed pants die. The knapweed seeds are then free to germinate in a competition free environment. Knapweed control by manual pulling of the adult plants, timed mowing of the adult plants, grazing of the adult plants, and herbicide application to the adult plants, is not a long-term solution to knapweed infestation because knapweed seeds remaining in the soil germinate after the weed control “treatment” and replace the knapweed plants that have been removed.
Accordingly, it is an object of the present invention to provide a weed control system.
Another object of the present invention is to provide a herbicide free control system.
Still another object of the present invention is to provide a weed control system that offers a long-term solution to knapweed infestation.
Other objects and advantages of the present invention will become more obvious hereinafter in the specification and drawings.
In accordance with the present invention, a weed control system has an opaque portion adapted to cover a ground region infested with weed seeds. The opaque portion blocks passage of light therethrough and blocks passage of seedlings growing from the weed seeds and up from the ground region. The system also has a growth promoting portion adapted to be disposed between the opaque portion of the system and the ground region. The growth promoting portion promotes germination of the weed seeds. The resulting weed seedlings die as the opaque portion prevents any light from reaching the seedlings.
Other objects, features and advantages of the present invention will become apparent upon reference to the following description of the preferred embodiments and to the drawings, wherein corresponding reference characters indicate corresponding parts throughout the several views of the drawings and wherein:
Referring now to the drawings and more particularly to
Weed control system 10 is essentially a two-part or layered system defined generally by (i) a top part 12 that is both opaque and strong, and (ii) a bottom part 14 that will promote germination of weed seeds 102. More specifically, top part 12 is typically a flexible sheet of light blocking material that can be readily deployed to cover and be secured to (e.g., staked, weighted, etc.) the relevant area of ground region 100. At the same time, top part 12 must be strong enough to prevent weed seedlings 104 from poking therethrough when seedlings 104 grow up from ground region 100. In this way, weed seedlings 104 cannot receive light when emerging from ground region 100 and will, therefore, die in a relatively short period of time. In order to prevent weed seeds 102 from lying dormant in ground region 100, bottom part 14 serves to promote germination of weed seeds 102 to thereby convert most or all of weed seeds 102 to weed seedlings 104 which will be killed when they emerge from ground region 100. This reduces or eliminates the weed seed population and, further, prevents re-population by more weed seeds since no adult weed plants are allowed to grow and deposit a new crop of weed seeds.
Bottom part 14 of weed control system 10 is typically a particle form (e.g., powder, pellets, etc.) of a material that will promote the growth of weed seeds 102. The particular material used can depend on the type of weed/weed seed population that is to be controlled. For example, if the particular type of weed seeds can have the germination thereof directly promoted, the germination material used in bottom part 14 can be a well-known growth enhancer such as gibberellic acid or kinetin. However, as will be explained further below, some weed species employ mechanisms that would inhibit germination. In such instances, the material used in bottom part 14 could be chosen to disable the particular weed species mechanism that inhibited germination. For example, in the case of the pervasive weed Centaurea maculosa (also known as “spotted knapweed”), adult weeds secrete racemic catechin which inhibits germination of the Centaurea maculosa seeds. In this instance, activated carbon can be used to adsorb the racemic catechin to effectively disable the weed germination inhibition mechanism as will be explained further below.
Regardless of the type of weed germination promoter(s) used in bottom part 14, the particlized form of the material can be coupled to top part 12 in a variety of ways. For example, in
Particles 140 could also be supported in a carrier as shown in
As mentioned above, top part 12 must be opaque and strong enough to prevent “poke through” by weed seedlings. However, top part 12 can be impervious to the passage of moisture or moisture permeable without departing from the scope of the present invention. Note that moisture permeability may be desired to facilitate the release of particles 140 (from either top part 12 or carrier 142). It is to be understood that such moisture permeability is to be achieved for top part 12 without negating its ability to block light and prevent seedling “poke through”.
By way of illustrative example, an embodiment of the present invention, can be configured for the control of the exotic weed Centaurea maculosa. As previously explained, adult Centaurea maculosa plants secrete racemic catechin into the surrounding ground region to inhibit germination of Centaurea maculosa seeds in the same region. Control of this particular weed using the present invention's weed control system will be explained with the aid of
Once the adult plants (i.e., both Centaurea maculosa plants and other vegetation) in ground region 200 have been reduced in height, the weed control system of the present invention is placed on and secured to ground region 200. In
The present invention could also make use of more than one type of weed seed germination promoter. For example, the weed seed promoters could function differently and be time-released so that each promoter's operating mechanism optimized the weed control results. By way of example, a multiple promoter system is illustrated in
The advantages of the present invention are numerous. Long-lasting weed control is achieved as the weed seed population is both greatly reduced and prevented from being re-populated. No spraying of herbicides is required. Indeed, no herbicides of any kind are required. The present invention is an entirely new approach to weed control that operates to eliminate both adult weeds while reducing/eliminating the weed seed population in a treated region.
Although the invention has been described relative to a specific embodiment thereof, there are numerous variations and modifications that will be readily apparent to those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described.
