Growth substrate product formed of mineral wool

Abstract

This invention includes a coherent growth substrate product formed of mineral wool, the product having two opposed top and bottom surfaces and a seed hole extending from the top surface towards the bottom surface, the base of the seed hole defining a seed bed, wherein the volume of the growth substrate product is not more than 150 cm.sup.3, and wherein the seed bed has a width of at least 5 mm.

Claims

1. A coherent growth substrate product formed of mineral wool, the product having a top surface opposed from a bottom surface and a seed hole extending from the top surface towards the bottom surface, the base of the seed hole defining a seed bed, wherein the volume of the growth substrate product is not more than 150 cm.sup.3, wherein the seed bed has a width in the range of 5 mm to 10 mm and a depth in the range of 7 mm to 15 mm, wherein the density of the mineral wool immediately surrounding the seed hole is greater than the density of the remainder of the mineral wool forming the growth substrate product, wherein the density of the growth substrate product is 70-85 kg/m.sup.3, and wherein the seed bed is generally circular or generally elliptical and wherein the base of the seed bed is substantially flat.

2. A growth substrate product according to claim 1 in which the seed bed has a width at least 6 mm.

3. A growth substrate product according to claim 1 in which the seed bed has a width at its narrowest point of not more than 8 mm.

4. A growth substrate product according to claim 1 in which the seed hole has a depth at least 9 mm.

5. A growth substrate product according to claim 1 in which the seed hole has a depth not more than 15 mm.

6. A growth substrate product according to claim 1 in which the seed hole is generally cylindrical or generally frustoconical.

7. A growth substrate according to claim 1 comprising at least one wetting agent.

8. A method for forming a seedling, comprising: providing, during a propagation stage of a commercial plant growing operation, a growth substrate product according to claim 1; positioning the product such that the top surface is uppermost; positioning a seed on the seed bed of the product; irrigating the growth substrate product; and allowing germination and growth of the seed to form a seedling.

9. A method according to claim 8 in which the seed bed has a width at least 6 mm.

10. A method according to claim 8 in which no particulate covering material is applied on top of the seed on the seed bed.

11. A method according to claim 8 wherein the seed is positioned in the seed hole using a nozzle seeder.

12. A process of making a growth substrate product as defined in claim 1 comprising providing a coherent mass of mineral wool having volume not more than 150 cm.sup.3 and opposed top and bottom surfaces and forming in the mass of mineral wool a seed hole extending from the top surface towards the bottom surface, and having a base defining a seed bed, the seed bed having a width at of at least 5 mm, wherein the seed hole is formed by punching.

13. A process according to claim 12 in which the seed bed has a width at least 6 mm.

14. A growth substrate product according to claim 1 in which the seed bed has a width at its narrowest point of not more than 7 mm.

15. A growth substrate product according to claim 1 in which the seed hole has a depth not more than 12 mm.

16. A growth substrate product according to claim 1 in which a seed is located in the seed hole and a film or sheet extends across, and is connected to, the top surface of the product so as to cover the seed hole.

17. A growth substrate product according to claim 1 further comprising: a seed located in the seed bed; and wherein the top of the seed bed is free of a particulate covering.

18. A growth substrate product according to claim 1, wherein the growth substrate product comprises a binder and a wetting agent, the wetting agent being present in an amount (by weight) of 0.01 to 5% based on the weight of the binder, wherein the coherent growth substrate product is adapted for use in a commercial plant growing operation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Following hereinafter are a number of drawings, with reference to which the mineral wool growth substrate product and process of making the same according to the invention are further illustrated.

(2) FIGS. 1a to 1c are schematic, cross sectional views of embodiments of the mineral wool product provided with a cylindrical seed hole;

(3) FIG. 2 is a schematic, cross sectional view of a seed hole including a germinated seed;

(4) FIG. 3 is a schematic, cross sectional view of the mineral wool product provided with a differently shaped seed hole;

(5) FIG. 4 is a schematic, cross sectional view of a seed hole and the punching equipment being used to illustrate the process of making the seed hole;

(6) FIG. 5 is a schematic, perspective view of an array of growth substrate products;

(7) FIG. 6 is a schematic, cross sectional view of an array of growth substrate products provided with seeds.

DETAILED DESCRIPTION OF THE INVENTION

(8) In the accompanying drawings, FIGS. 1a to 1c each show a cross section of a preferred growth substrate for use in the invention.

(9) In FIG. 1 a the growth substrate 1 has a top surface 2 and a bottom surface 3. A substantially cylindrical seed hole 4 extends from the top surface 2 towards the bottom surface 3, to a seed bed B formed by the base of the seed hole. In this embodiment the seed bed B is flat and has width 6 mm.

(10) In this embodiment the growth substrate is generally cylindrical with a diameter of 20 mm and a height of 25 mm with the diameter of the seed hole 4 being 6 mm at all depths and its depth being 10 mm.

(11) In use a seed 5 is positioned inside the seed hole 4. The seed hole has been formed by punching, as illustrated in FIG. 4, and so there is a region X surrounding the seed hole, having density higher than the average overall density of the growth substrate.

(12) FIG. 1 b is similar except that the seed bed B is in the form of a shallow cone and has depth 1 mm. The width of the seed bed is the same as in FIG. 1a, namely 6 mm.

(13) FIG. 1b is similar except that the seed bed B is in the form of a shallow concave dip and has depth 1 mm. The width of the seed bed is the same as in FIG. 1a, namely 6 mm. Additionally, the seed hole is frustoconical rather than cylindrical, with the width at all depths being more than 6 mm. A frustoconical seed hole could of course be combined with a seed bed B having the configuration in FIG. 1a or 1b.

(14) In the invention rapid, strong and uniform growth is obtained due to the configuration of the seed hole leading to an optimal balance of water and oxygen for the seed and to optimum free space allowing the seeds to germinate freely.

(15) FIG. 2 shows a view of the seed hole 4 in a growth substrate 1 with a top surface 2, after a seed 6 has germinated and the first root 10 has developed. This demonstrates the free space available to the seed for root growth.

(16) The free space enables the root 10 and sprout 9 to find their way into the growing direction without resistance so the root 10 will point downwards and the sprout 9 will point upwards. This way the seed will anchor better and develop in a uniform manner.

(17) FIG. 3 shows a cross-section of a different embodiment of the growth substrate product 1 having a differently shaped seed hole 4. In this case the upper part 4a is substantially frustoconical and the lower part 4b is substantially cylindrical in shape. The seed bed B is cylindrical. As with the embodiments of FIGS. 1a to 1c, the width of the seed hole at its narrowest point is 6 mm. At its widest point the width is greater.

(18) FIG. 4 illustrates schematically the production of a growth substrate product 1 using a punching method. According to this a punching tool or spine 11 is used to form the seed hole 4 including the seed bed B by being pressed vertically into the top surface of the growth substrate. The punching tool 11 has one pointed end 12. Since the seed hole is formed without removal of material, a compressed region at the surface of the seed hole is formed, designated as shaded area X in FIG. 4. This compressed region X of the seed hole provides higher density of the growth substrate surrounding the seed hole 4 and thereby ensures a concentration of water in the part of the growth substrate which is close to or in contact with the seed, which encourages improved rooting-in.

(19) FIG. 5 illustrates a product which is a joined array of growth substrate products 1. In this case they are formed as an integral array formed of mineral wool. In this Figure the seed holes are not illustrated. When it is required to use the products 1 then they can be broken from the array along the broken lines 8.

(20) FIG. 6 shows a cross-sectional view of an array of separate growth substrate products 1, each having a seed hole at the top surface 3 of the product in which a seed 3 is positioned. The products 1 are not integrally formed but are joined by a sheet 13 which is attached to the top surfaces 2 of the product 1 using adhesive 14. Preferably the sheet is of paper. This way the propagator does not have to undertake the time-consuming process of applying the seeds to the growth substrate products. Furthermore, the sheet 13 connecting the growth substrate products 1 allows the propagator to dispense with a tray or other carrier.