Method of growing plants

Abstract

The invention provides a method of growing plants in a mineral wool growth substrate, the method comprising: providing at least one mineral wool growth substrate comprising man-made vitreous fibers bonded with a cured binder composition, and positioning one or more seeds or plants for growth in the growth substrate, and allowing growth of the one or more plants,
wherein the binder composition prior to curing comprises: a) a sugar component, and b) a reaction product of a polycarboxylic acid component and an alkanolamine component,
wherein the binder composition prior to curing contains at least 42% by weight of the sugar component based on the total weight (dry matter) of the binder components.

Claims

1. A method of growing plants in a mineral wool growth substrate, the method comprising: providing at least one mineral wool growth substrate comprising man-made vitreous fibres bonded with a cured binder composition, and positioning one or more seeds or plants for growth in the at least one mineral wool growth substrate, and allowing growth of the one or more seeds or plants, wherein the cured binder composition comprises the following initially uncured binder components: a) at least 45% by weight of a sugar component based on the total weight (dry matter) of the initially uncured binder components, and b) a reaction product of a polycarboxylic acid component and an alkanolamine component, wherein the at least one mineral wool growth substrate further comprises a wetting agent; and wherein the sugar component is a reducing sugar having a dextrose equivalent (DE) of 40 to 100.

2. The method according to claim 1, wherein the wetting agent comprises an ionic surfactant.

3. The method according to claim 1, wherein the wetting agent comprises an anionic surfactant.

4. The method according to claim 3, wherein the anionic surfactant comprises linear alkyl benzene sulphonate anionic surfactant.

5. The method according to claim 1, wherein the sugar component comprises a reducing sugar.

6. The method according to claim 1, wherein the polycarboxylic acid component comprises a carboxylic anhydride.

7. The method according to claim 6, wherein the carboxylic anhydride component comprises a combination of a cycloaliphatic anhydride and an aromatic anhydride.

8. The method according to claim 1, wherein the sugar component is a reducing sugar having a DE of 50 to 100.

Description

EXAMPLES

(1) The following methods were used to establish the water retention and the re-saturation of a sample.

(2) Water Retention

(3) The principle is described in EP-A-310501. In principle, the samples are saturated with water and are then put on a sand bed. Using as a reference the middle of the sample, the sample is then put via the sand bed on an underpressure of 10 cm water column. After 4 hours, the sample is taken from the sand bed and weighed. On basis of the measured dry and wet weight and the measured dimensions of the sample, the water content on a volume basis is calculated.

(4) Re-Saturation

(5) Samples are saturated with water and then drained until the samples have a total water content of 50% + or 2%. Then the samples are placed in a container in which the height of the water is 5 mm. after 4 hours the samples are taken out of the container and weighed. The weight after 4 hours is measured and this result together with the dimensions of the sample gives a water content on a volume basis after 4 hours. This is then a measure for the re-saturation capacity.

(6) Preparation of Binder Component Resin (b)

(7) 158 g of diethanolamine (DEA) are placed in a 1-liter glass reactor provided with a stirrer and a heating/cooling jacket. The temperature of the diethanolamine is raised to 60 C. whereafter 91g of tetrahydrophthalic anhydride (THPA) are added. After raising the temperature and keeping it at 130 C., a second portion of 46 g of tetrahyrophthalic anhydride is added followed by 86 g of trimellitic anhydride (TMA). after reacting at 130 C. for 1 hour. After cooling to ambient temperature, the obtained resin is ready for use.

(8) The solids content of the binder was measured as 58%.

(9) Larger amounts of the binder component resin (b) were prepared for the binder copositions following the above producer.

(10) Preparation of Binder Composition

(11) 3000 liter binder composition was prepared by first mixing 515 liter resin (b) binder component with 141 liter Ammonia, 22 liter hypophosphorous acid and 9.2 liter standard silane (gramma-aminoprpyltriethoxysilane). Afterwards, this mixture was mixed with 601 liters sugar component (a), Sirodex 431 from Syral.

(12) Finally, this binder mixture was diluted with water to 22% solids and further diluted before use.

(13) Larger amounts of the binder composition can be prepared for the production of the growth substrates by following the above procedure.

(14) Preparation of Wetting Agent (c)

(15) Linear alkyl benzene sulphonate anionic surfactant and monoethylene glycol were mixed in a 1.25:1 ratio to produce wetting agent (c) (LAS/MEG).

(16) Preparation of Products of the Invention (Hereinafter Product 1)

(17) The binder composition was prepared as described above. This binder composition (at an appropriate rate so as to achieve the quoted LOl values) and the prepared wetting agent (at a rate of 5.71 wetting agent/ton mineral wool) were fed into a cascade spinner and sprayed onto mineral fibres. The coated fibres were then collected on transport conveyors and transported to a curing oven for curing at 275 C. for 5 to 15 minutes to form a mineral fibre product. This product was then cut into plugs or blocks of the desired shape and seed holes were drilled as required.

Example 1

(18) Eight block products were tested using the method above to establish the water retention and re-saturation levels. Products 1A to 1E are Product 1 and were according to the invention and product 1 F was a reference sample including phenol urea formaldehyde (PUF) binder. All blocks had a density of 75 kg/m.sup.3.

(19) TABLE-US-00001 Block 10 cm 10 cm 6.5 cm Product 1A 1B 1C 1D 1E 1F LOI (%) 3.2 3.2 2.2 3.5 3.2 2.6 WC-10 83.0 84.0 83.0 81.0 80.0 71.0 Re-Saturation 79.0 76.0 76.0 79.0 79.0 75.0

(20) As indicated above, the WC-10 (measure of water retention) and re-saturation values were higher for the products of the invention, that is products 1A to 1E, than they are for the reference sample. This indicates that the product of the invention has a higher re-saturation value and a higher water retention value. These properties are advantageous for growing plants, since they mean that in the case of the WC-10 value that the grower does not need to water the plants so often, as the product will retain more water. It also means that due to the higher re-saturation value, it will be easier for the products to suck up water if the WC value decreases too far.

Example 2

(21) In Example 2 there are four products tested which were plugs of 20 mm diameter and 25 mm height. Plug samples 2A, 2B and 2C were Product 1 and are of the invention and sample 2D is a reference case including PUF binder. As was shown above with the blocks, the WC-10 and re-saturation values are higher in the product of the invention than they are in the reference sample. All plugs had a density of 80 kg/m.sup.3.

(22) TABLE-US-00002 Plug trials Product 2A 2B 2C 2D LOI (%) 4.3 4.5 4.8 3.1 WC-10 85.0 86.0 84.0 73.5 Re-Saturation 79.0 79.0 79.0 71.9

Example 3

(23) The percentage of useable transplants for a Viper (Enza) crop was compared in three different plug types. These were: 3A, a stone wool fibre product with a phenol-urea formaldehyde (PUF) binder and a non-ionic surfactant wetting agent; 3B, which was Product 1; and 3C, a stone wool fibre product with a PUF binder and LAS/MEG wetting agent. All the plugs had a density of 80 kg/m.sup.3.

(24) Please see the table below in which X indicates that there was an empty spot, that is the seed was not present in the plug, O indicates that the plant was not useable and UT represents useable transplants. The criteria used to establish the number in each category was determined by selection machine.

(25) TABLE-US-00003 3A 3B 3C Tray nr X O UT X O US X O UT 1 5 25 210 2 28 210 8 36 196 2 5 18 217 7 24 209 7 31 202 3 1 34 205 2 23 215 3 32 205 4 6 45 189 3 23 214 6 26 208 5 7 26 207 7 25 208 5 33 202 6 7 27 206 5 21 214 8 27 205 7 5 19 216 8 36 196 8 8 22 210 6 19 215 9 5 31 204 3 31 206 10 3 29 208 Average 5.2 27.6 207.2 4.3 24.0 211.7 6.0 30.1 203.9 Stdev 2.0 7.9 7.7 2.3 2.4 3.0 2.0 5.4 5.9 % 2.2 11.5 86.3 1.8 10 88.2 2.5 12.5 85.0

(26) As is shown, the average number of useable transplants in the present invention, that is in 3B, is 88.2, which is higher than the Reference Examples 3A and the 3C which are 86.3 and 85.0 respectively. This improvement on the percentage of useable transplants shows one of the advantages of the present invention. The mineral growth substrate of the present invention resulted in more useable transplants and reduced both the number of empty spots and the number of not useable transplants.

Example 4

(27) In this Example, seeds of Maxifort were sowed in April and selection was carried out 12 days later. The selection was carried out by a selection machine with the following pixels determined to arrive at the different classes A to E.

(28) TABLE-US-00004 Class Pixels > A 2000 B 1400 C 800 D 450 E

(29) TABLE-US-00005 Absolute number of plants through the vision system at selection machine A B C D E Total Lost 4A 186 330 284 66 124 990 18 4B 135 300 310 78 160 983 25 4C 303 290 205 62 135 995 13 4D 305 267 218 48 140 978 30 % of plants per class at selection machine Class A B C D E 4A 19 33 29 7 13 4B 14 31 32 8 16 4C 30 29 21 6 14 4D 31 27 22 5 14

(30) Examples 4A and 4B were reference samples. 4A was a stone wool fibre product with a PUF binder and Rewopal wetting agent, 4B was a stone wool fibre product with a non-ionic surfactant. Examples 4C and 4D were Product 1. 4C has a LOI of 4.5%. 4D had a LOI of 3.0%. As shown above, in the present invention Examples 4C and 4D have more plants in Class A than the reference samples. Examples 4C and 4D each also have more plants in Classes A and B combined than Examples 4A and 4B. This shows the great improvement of the plug of the present invention.

(31) Qualitatively class A is the best quality of plants that can be used immediately for sales or for further use in blocks or for grafting.

(32) Class B are put back for 1 to 2 days to grow more and to get into Class A.

(33) Class C are put back for more days, that is more than 2 days, to grow more and to get into Class A.

(34) Class D in most cases are small plants which are waste and require too much further input to get into Class A.

(35) Class E: in these cases the seeds did not germinate or the plant died.

(36) Lost: in these cases there was no seed present.

Example 5

(37) This Example is to show the seeding of the plugs in a standard 240 tray. Sowing was performed by a standard sowing machine. 5A was a stone wool fibre product with a PUF binder and Rewopal wetting agent. 5B was a stone wool fibre product with a non-ionic surfactant. 5C and 5D were Product 1. 5C had a LOI of 4.5%. 5D had a LOI of 3.0%. The results are shown in the table below.

(38) TABLE-US-00006 Total Badly Positioned Missing Seeds & Badly Missing Seeds Seeds Positioned Seeds 5A 1 0 0 0 2 0 0 0 3 0 1 1 4 No data available No data available No data available 5 1 2 3 Av 0.25 0.75 1 Sd 1 1.0 1 5B 1 0 2 2 2 0 3 3 3 0 8 8 4 0 1 1 5 1 1 2 Av 0.2 3 3.2 Sd 0 3 3 5C 1 1 1 2 2 0 1 1 3 0 0 0 4 1 0 1 5 0 0 0 Av 0.4 0.4 0.8 sd 1 0.5 1 5D 1 1 1 2 2 2 0 2 3 1 0 1 4 0 1 1 5 0 1 1 Av 0.8 0.6 1.4 sd 1 0.5 1

(39) As indicated in the data above, the mineral wool product of the invention leads to improved seeding compared to the reference examples. In particular, 5C and 5D had an average total missing seeds and badly positioned seeds of 0.8 and 1.4 respectively. This compares to the 3 and the 3.2 of the 5A and 5B respectively. 5B in particular had lots of seeds in between the plugs and seeds on top of the plug. The seeding performance of 4C and 4D is better than the reference samples.

Example 6

(40) In this example, 6A shows the compression stiffness of a plug of Product 1 versus a plug made using a reference sample 6B. As shown, 6A has the same LOI as 6B, and the plugs of the invention have a greater compression strength than the reference sample 6B.

(41) 6C and 6D are blocks made using Product 1. These show a higher compression strength than 6E, the reference sample, for the same LOI. 6B and 6E were each a stone wool fibre product with a PUF binder.

(42) In this example all products were semi finished products (SFP), which is the mineral wool before it is formed into the end productthis means it is possible to determine compression strength, which cannot be done on end-product plugs. SFP plugs have dimensions 100 mm (length)152 mm (height)67 mm (width), density 80 kg/m3. SFP blocks have dimensions 100 mm (length)106 mm (height)67 mm (width), density 75 kg/m3. Compression strength values are measured by Zwick apparatus.

(43) A higher compression strength means that the product is less likely to be damaged during use. A further advantage of a stronger product is that a smoother seed bed/hole can be formed. A smoother seed hole means that the seed is more likely to propagate from the ideal position in the seed bed/hole. The seed is additionally less likely to bounce out of the desired area, and/or be caught another part of the mineral fibre product. Accurate positioning of seeds leads to greater uniformity of the resulting crop which is advantageous for the propagator.

(44) TABLE-US-00007 Overview compression stiffness trials plugs and blocks. Compression Strength LOI (%) (N/cm2) SFP Plugs SFP 6A 3.2 262 6B 3.2 208 Blocks SFP 6C 2.4 200 6D 2.4 183 6E 2.4 176