Root control bag

Claim 2

A root control bag having a wall manufactured from a non-woven fabric formed of a multiplicity of substantially continuous, randomly aligned, polymeric fibres, needle puncture bonded together, the physical characteristics of said fabric being such that when subjected to a set of standard probe penetration tests as herein defined in not more than 331/3% of the tests is the initial puncture load greater than 1 kg, and in not more than 2% of said tests is the final penetration load less than 1.25 kg, said fabric having a resistance to deterioration such that no significant deterioration of said physical characteristics will be shown over a period of prolonged use under normal conditions.

Claim 3

A root control bag according to claim 1 wherein said wall comprises said fabric which when subjected to a set of standard probe penetration tests in not more than 2% said tests is the final penetration load less than 1.75 kg.

Claim 4

A root control bag according to claim 1 wherein the fibres from which said fabric is formed comprise ultra-violet stabilized polypropylene filament.

Claim 5

A root control bag according to claim 1 wherein said fabric has been mechanically bonded by needle punching at a needle punch density of not less than 150 punchings per square centimeter of fabric material.

Claim 6

A root control bag according to any claim 1 wherein said fabric has a mass of between 100 and 250 g/m 2 .

Claim 7

A root control bag according to claim 1 wherein said bag has a base formed of a high strength reinforced impervious plastic material having a tensile strength of not less than 10 kN/m.

Claim 8

A root control bag according to claim 6 wherein said base is stitched to said walls with a combined overlocking and plain chain stitch using stitching yarn having a breaking strength of not less than 1 kN.

Claim 9

In a method for growing plant stock for later transplantation the specific improvement comprising: (a) excavating a hole in the ground (b) inserting within the hole a root control bag having a wall manufactured from a non-woven fabric formed of a multiplicity of substantially continuous, randomly aligned, polymeric fibres, needle puncture bonded together, the physical characteristics of said fabric being such that when subjected to a set of standard probe penetration tests as hereinbefore defined in not more than 331/3% of the tests is the initial resistance to puncture greater than 1 kg, and in not more than 2% of said tests is the final resistance to final penetration less than 1.25 kg, said fabric having a resistance to deterioration such that no significant deterioration of said physical characteristics is shown over a period of prolonged use under normal conditions. (c) filling said bag with growing media, and (d) growing a plant within said bag in the ground such that the bag and the growing plant can thereafter be excavated from said ground and transported for transplantation elsewhere.

Claim 10

In a method for growing plant stock for later transplantation the specific improvement comprising: (a) excavating a hole in the ground (b) inserting within the hole a root control bag having a wall manufactured from a non-woven fabric formed of a multiplicity of substantially continuous, randomly aligned, polymeric fibres, needle puncture bonded together, the physical characteristics of said fabric being such that when subjected to a set of standard probe penetration tests as hereinbefore defined in not more than 331/3% of the tests is the initial resistance to puncture greater than 1 kg, and in not more than 2% of said tests is the final resistance to final penetration less than 1.25 kg, said fabric having a resistance to deterioration such that no significant deterioration of said physical characteristics is shown over a period of prolonged use under normal conditions. (c) filling said bag with growing media, and (d) growing a plant within said bag in the ground such that the bag and the growing plant can thereafter be excavated from said ground and transported for transplantation elsewhere.

Claim 11

A method according to claim 8 wherein the method includes the further step of retaining the bag and plant in ground for a time period such that further plant growth is restricted by girdling effect of the fabric on all roots prior to the excavation of said plant from said ground.