MXPA97001956A

MXPA97001956A - Printing of semil

Info

Publication number: MXPA97001956A
Application number: MXPA/A/1997/001956A
Authority: MX
Inventors: Robert Rowse Hugh; Michael Terence Mckee John
Original assignee: The Minister Of Agriculture Fisheries & Food In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland
Priority date: 1994-09-16
Filing date: 1997-03-14
Publication date: 1997-06-01

Abstract

The present invention relates to a method for controlling a seed in terms of its water content, characterized in that it comprises contacting the seed with a first surface of a semipermeable membrane having a first and second surface, the second surface is in direct contact with a solution of predetermined osmotic potential, so that the seed extracts water from the solution through the membrane, where the seed and the semi-permeable memebrana are caused to be constantly or periodically moving one in relation to the other. In this manner, the seed is constantly or periodically reoriented with respect to the first surface so that the water transfer occurs uniformly over substantially the entire surface area of the seed.

Description

PRIMING SEEDS FIELD OF THE INVENTION The present invention relates to a method for treating seeds by controlling their water content, in particular to the priming and / or germination of seeds or the induction of the desiccation tolerance therein. The invention further provides seeds primed, germinated or made tolerant to desiccation by the method of the invention and to an apparatus for carrying out the method.

BACKGROUND OF THE INVENTION Seed priming is a process for treating plant seeds that enables them to undergo faster and more uniform germination by seeding or planting, with the option to simultaneously treat them with fungicide or other preservatives that provide protection during processing or after sowing and allowing their prolonged storage, that is, in packages exhibited at the point of sale.

REF.24212 This process allows the seeds to absorb enough water to enable the beginning of their pregerminative metabolic processes and then stop them at that stage. The amount of water absorbed must be carefully controlled since too much will simply allow the seed to germinate and very little will result in the aging or maturation of the seed. Once the correct amount of water has been absorbed, it is then necessary to hold the seed in that water content for a period, typically one or two weeks, before re-drying it to the original water content for storage. When the seeds are subsequently sown in the usual way they germinate more quickly and uniformly than the unprimed natural seeds and, where the geographical location of the priming point allows it, the seeds can be sown directly after the priming without drying after which they germinate even faster than those that have been primed and dried.

The conventional way of priming Seeds has been to immerse them in an aerated solution of an osmotic material, in the usual way polyethylene glycol (PEG). The coating of the seed is more or less impervious to PEG such that the osmotic potential of the seed tends to balance with that of the solution; the concentration of the PEG that is chosen is such that it will not allow the seed to absorb enough water to germinate. This works well for many species but priming large amounts of seeds requires large amounts of the PEG solution and this can cause waste disposal problems, particularly if fungicides have been added. The immersion in liquid also restricts 1? Oxygen absorption and some seeds, particularly onions, will only be successfully primed if the solution is aerated using enriched air c or r. or oxygen.

To avoid the problems of large-scale priming with the PEG, the system known as "drum priming" was devised (see US Patent No. 5119598 = The British Patent No. 2192781). This involves first carrying out tests on a batch of seeds to determine the optimum level of hydration and then hydrating the volume of seeds in a drum that is slowly rotated about its horizontal longitudinal axis. Water is added to the drum more slowly than the seeds are able to absorb so that they become hydrated without ever appearing wet. The seeds are incubated in a revolving drum with access to the air for a period appropriate to its type before drying.

An alternative method of seed priming is known as "matrix priming" and does not involve the use of PEG but uses a medium absorber such as clay or peat to absorb the water and then transfer it to the seeds (see US Patent No. 4912874). The extension of the hydration of the seeds is controlled by altering the water content of the medium and the seed / seed. The process is completed by removing the seeds from the medium with optional drying. Both drum and matrix primers have been developed to avoid the problems of using PEG when printing large quantities of seed.

Additional seed treatments involving the control of the water content of the seed are the induction treatments of tolerance to desiccation and germination. The treatment to produce germinated seeds may involve treatment similar to priming as described above with the treatment being continued until the radicle emerges. The seed thus produced can be dried by addition and / or coated as described in US Patent No. 4905411. Separation of the germinated seed from the primed seed can be carried out using a seed sorter that operates to separate the seeds that show signs of the emergence of the radicle from those that do not show it. Such apparatus and methods are exemplified by the publication of Kirin Brewery Co Ltd JETRO, May 1994 where a CCD video camera is used to observe the color and size of the seed tissue and a compressor device is used to move the developed seed selected from the undeveloped seed. The treatment for the induction of the tolerance of desiccation in seeds with the emerged radicles was exemplified by the International Patent (WO) No. 94/05145 wherein the content of the seed is held between 35 and 55% of the weight such that the emerged radicle does not develop while other metabolic processes continue.

DESCRIPTION OF THE INVENTION The present invention provides an additional method and apparatus for controlling the water content of seeds that do not require a constant active addition of water, as required in conventional drum primers, but use a semipermeable membrane to mediate the transfer of water from a solution of osmotic pressure established to the seed. The use of this method allows the formation of automated forms of the apparatus to carry out the method. The invention also concerns the requirements of treating small quantities of seeds simultaneously in multiple batches, such as are required when printing high value flower seeds of different varieties, with the advantages of drum priming over matrix primer with regarding the separation of seeds after treatment.

Particular conveniences are provided using the present method and apparatus for treating seeds that have mu sic coatings, for example those such as the seeds of Salvia and Thought; and in a special way to print such seeds. These seeds do not respond well to other methods of water treatment, that is to say to the methods of priming, when the layer of mucilage becomes swollen with water and restricts the exchange of gas necessary to reger my action and the development of the seed . The semi-permeable membrane apparatus was reported to be used to represent water overload on seed germination in a seedbed (see Rowse et al. (1986) Rep. Atn. Veg. Res. Stn. For 1985) wherein the seeds were germinated between a ceramic dish and a semi-permeable pouch of PEG solution, with further development by Fyfield et al. (1989) J. Botany Experimental, Vol. 40, no. 215, pp 667-674. This last work was not directed to seed production for drying and / or packing but was concerned with the determination of ideal conditions for the emergence of the radicle in mung bean seeds.

In a first aspect of the present invention there is provided a method for treating a seed to effect the control of its water content comprising contacting the seed with a first surface of a semi-permeable membrane having the first and second second surfaces, the second surface that is in direct contact with a solution of potential osmdti: ^ preetermined such that the seed subtracts the water from the solution through the membrane, er. where the seed and the semi-permeable membrane are constantly or periodically motivated to move relative to one another such as constantly or periodically reorienting the seed cor. with respect to the first surface such that 1 J water transfer occurs uniformly over substantially the entire surface area of the seed.

In a preferred method of the first aspect of the present invention there is provided a method for priming or germination or induction of desiccation tolerance in a seed wherein the solution of the predetermined osmotic pressure is such as to allow the Seed subtract the water from it through the semi-permeable membrane; the period for which the seed is treated, which is sufficient to allow the pregerminative metabolic processes inside the seed to be carried out to any level that includes immediately the emergence of the radicle for priming, up to the emergence of the radicle for germination and which is insufficient to support the growth of the radicle but sufficient to allow other metabolic processes to continue in the case of induction of tolerance to desiccation. Preferably the seeds and the semipermeable membrane are caused to move relative to one another such that the seeds are constantly reoriented with respect to the first surface by means of which they uniformly carry water over the entire surface areas , this in particular is done by causing the seeds to spin or jump through the membrane. More preferably, the semi-permeable membrane is provided in the form of a tube, ie of a circular or polygonal cross-section, and this tube is rotated with the seeds on its inner surface and the solution retained between its outer surface and a additional body, to which the membrane is sealed in a water impermeable manner or of which the membrane is an integral part.

The semipermeable membrane is such that, when the second surface (for example the outer surface of the tube) makes contact with the solution, the first surface (for example the inner surface of the tube) appears to be dry. It is preferred that only the contact of the seed, or some other intermediate absorbent body, with the first surface results in the transfer of water from the second surface. To facilitate the retention of the seeds within the confines of the tube of the semi-permeable membrane in use, it is preferred to use the tube format with retainer elements, ie lids placed at each end.

More preferably the semipermeable membrane is placed on a structure within a drum device such that it divides the drum device into outer and inner chambers which are isolated with respect to the transfer of water between the other two through the membrane Semi-peable same. Preferably the second chamber is completed by one or more non-permeable wall elements, preferably including those on which the semi-permeable membrane tube is mounted. The semi-permeable membrane can be made of any material that is permeable to water but impermeable to the predetermined osmotic pressure solution. Conveniently the membranes are those of cellulose and / or polycarbonate materials, with the addition of the fungicide to the solution which is in a potentially necessary form wherein the cellulose membranes are used to prevent fungal growth in the membrane. Suitable types of membranes include those that are used for dialysis, for example, for vising dialysis.

When formed in a tube the membrane can carry any cross-sectional shape but conveniently it can be a simple form of, for example, circular or polygonal or for example hexagonal or square. The speed at which this tube is rotated with the seeds held in its inner volume will vary with its diameter. The speed must be sufficient to effect the r e o n t a c t ion of the seeds with respect to the surface, without any particular limitation that is intentional. Typically this is around 0.8 to 1.2 rpm for a 110 mm diameter unit. The priming conditions with respect to the osmotic potential will vary from seed to seed with the solutions that provide between -0.5 to -2.0 MPa of osmotic potential in typical form that is used for priming or germination. The adequate osmotic potential to overload the seed to induce it to the tolerance of desiccation will be determined by the simple experimentation of banking, but it will be such as to produce a level of seed water sufficient to inhibit the growth of the radicle but high enough to allow other metabolic processes to continue, for example by providing a water content of 35 to 55% by weight of the seed. The preferred conditions will be consistent with those published in International Patent (WO) No. 94/05145.

The preferred temperature at which the method of the invention is carried out may vary with the seeds to be treated, but it is er. typical form between 10 and 25 ° C, more preferably between 15 and 20 ° C for priming and induction to the desiccation tolerance, and optionally up to as much as 40 ° C for 1 J germination. Such temperature control s < ? It conveniently achieves by carrying out 1 J rotation of the tube within a drag structure mounted within a temperature controlled environment, for example in a controlled temperature room.

Using the preferred tubular membrane method of the present invention wherein the inner and outer chambers contain a number of seeds and the predetermined osmotic potential solution respectively, convenience is provided wherein the seeds are mixed in a constant manner such that equal access is offered. to the membrane supplying the water, the osmotic solution (eg, aqueous PEG solution) is stirred or stirred constantly to minimize the concentration gradients that would otherwise pile up when the water is carried through the membrane, and the temperature gradients are prevented which would otherwise allow the pure water to be distilled in the colder parts of the unit and thus allow the seed to carry too much water to a point of contact. In a second aspect of the present invention there is provided the apparatus for carrying out the method of the invention, this one comprising a semipermeable membrane having the first and second surfaces, the first surface that is adapted to be in contact with a seed for treated in use, the second surface that is placed in a chamber adapted to contain a solution of predetermined osmotic potential in contact with the second surface such that in use the seed is capable of subtracting the water from the solution through the membrane in where the apparatus is adapted such that in use the first surface and the seed can be caused to move relative to one another such that the seed is periodically or constantly reoriented with respect to the first surface by means of which the water transfer is It performs uniformly on its entire surface area.

The semi-permeable membrane is preferably provided in the form of a tube of polygonal or circular cross section which is rotatable such that it is capable of carrying the seed on its inner surface with the solution retained in the chamber which is formed between its outer surface and an additional body to which the membrane is sealed in a waterproof form. The movement relative to the first surface and the seed preferentially induce the rotation and movement of vibration of the seed through the surface.

The semi-permeable membrane is preferably such that, when the outer surface of the tube makes contact with the solution, the inner surface of the tube appears to be dry, in particular form where only the contact of the seed or some other absorbent body with the first surface results in the transfer of water to the first side. The tube is conveniently provided with end caps. More conveniently the semipermeable membrane is placed on a support structure, for example a tubular structure, inside a drum device such that it divides the drum device into the outer and inner chambers which are isolated with respect to the transference of the water between the other two through the semipermeable membrane itself. In such an embodiment the outer chamber is conveniently completed by other non-permeable wall elements including those on which the semi-permeable membrane tube is mounted. The semipermeable membrane is made of any material that is permeable to water but impermeable to the solution of the predetermined osmotic pressure. Preferably the semi-permeable membrane is made of cellulose and / or polycarbonate material suitable for dialysis.

In a particular preferred embodiment of the invention the tube is mounted with its longitudinal axis substantially horizontally oriented on a drum device which is instead mountable on a roller structure such that it can be driven to rotate and thus cause the tube turn around its longitudinal axis. Thus, a preferred embodiment of the second aspect of the present invention provides the apparatus described hereinabove together with means for rotating it about its longitudinally oriented longitudinal axis, these driving means preferably comprising a driven roller structure system. l It will be understood by those skilled in the art that individual seeds, when applied in quantity to the chamber formed by the inner surface of the membrane, may not subtract their water directly from the semi-permeable membrane but also from the adjacent seeds. As long as such seeds are periodically or continuously reoriented such that even the water distribution is achieved, such a mechanism is contemplated as being adequate for the purposes of the present invention. Thus there is no intentional limitation on the method of action on all seeds, one or some of the seeds should at least contact the membrane directly.

The method, apparatus and seeds of the invention will now be described by the mode of the illustration only for reference to the figures and the non-limiting examples below. In addition, the modalities that fall within the scope of the invention will be present for those skilled in the art in its clarity.

Fl GURAS Figure 1: shows a cutaway perspective view of a drum mounted membrane apparatus according to the present invention as described in Example 1.

Figure 2: shows a cross-sectional view, as seen from the side of the drum-mounted membrane apparatus shown in Figure 1. Figure 3: shows an axial front view of the drum-mounted membrane apparatus of Figure 1 as it is mounted for rotation on a driven roller structure. Figure 4: shows a cutaway perspective view of an alternative embodiment of the apparatus of the invention of Example 2. Figure 5: shows a cross section through the end of the apparatus of Example 2 as seen with the longitudinal axis oriented in the form horizontal. Figure 6: shows a view of the lid and annular of the apparatus of Example 2 as seen in the direction of the arrows provided in Figure 5.

EXAMPLE 1: Apparatus of the invention A primer apparatus of the invention as shown in Figures 1 to 3 consists of a drum formed of two concentric cylinders; an inner PVC cylinder (1) which is a highly perforated and rigid tube in which a semi-permeable flexible membrane tube (2) is supported in use, and a non-drilled outer PVC cylinder (3). The methyl acrylate caps (Perspex) (4) are provided at both ends of the inner cylinder and seal, a solution of osmotic potential established within the chamber (5), formed between the outer cylinder (3) and the membrane (2). ), and retains the seed in the inner chamber (6), with the separation zone provided by the 2 mm sheet rubber gaskets (7). The seeds are placed in the chamber (6) formed by the inner surface of the membrane (2). The membrane (2) is a tubular visking dialysis membrane with its diameter equal to that of the chamber (6) and made of cellulose; it is supplied by Medicell International Ltd., 239 Liverpool Road, London NI 1LX, UK. To enable the rotation of the membrane relative to the seeds in use, the drum is mounted on a roller structure (production rollers of Belico cell) using rubber rollers. Three drum sizes of the invention are provided for use in this structure, each having a different capacity for the seeds; 25 g of capacity that is 64 mm in diameter by 58 mm in length; 50 g capacity which is 64 mm in diameter by 144 mm in length and 100 g in capacity which is 81 mm in diameter and 210 mm in length; all are dimensions of the inner cylinder. The inner cylinder is fixed in place on the outer cylinder by means of the fixed end cap (4a) and the removable end cap (4b) retained by a screw (8), the rod (10) and the wing nut (9) The screw (11) allows access to the chamber (5) to replenish the water content of the solution while the screw (8) has a central passage that allows the transfer of the respiratory gases to and from the atmosphere.

EXAMPLE 2: Alternative apparatus of the invention An alternative arrangement of an apparatus of the invention is shown in Figures 4 to 6. In Figure 4 an outer PVC cylinder (12) and an inner perforated PVC cylinder (13) define an exterior chamber (14) between them. which is separated from an inner chamber (15) with respect to the flow of the liquid by a semi-permeable membrane tube (16) originated as described in Example 1. The inner cylinder is mounted in relation to the outer cylinder by means of two parts of the annular or methyl acrylate ring (perspex) (17) which are mounted instead on the outer cylinder (12) by means of the intermediate mounting elements (18) and the screws (19a, 19b, 20); the presence of the two screws (19a and 1) that fix the elements (18) to the cylinder that inhibits the movement of the element f was of the axial alignment with the screws (20). The screws 20 carry O-rings or washers (20a). The rings consist of front plates (17a) with rear plates (17b) screwed onto them by the screws (25) with the ring-shaped rubber gaskets (22) held between the two. The predetermined osmotic potential solution is added to the chamber (14) through one or both of the two sealed ports in use by the screws (21) having o-rings or washers (21a) around their bodies. These screws are passed through the through holes (24) in the end caps (23). The rubber sheet gaskets (22) reside between the annular and the inner and outer cylinders (12) and (13) at each end of the apparatus to prevent leakage of the solution from the chamber. The semi-permeable membrane (16) is held tightly through the inner cylinder between the packing and the cylinder (13). The inner chamber (15) is closed by the methyl acrylate caps (23) at each end; these are retained in place by the nuts (27) which engage the projections of metai with rope (28) projecting from the annular or assemblies with similar ropes which freely join them to the annular at each end. At least one of the covers (23) has an air gap that allows the passive exchange of the respiratory gases between the chamber (15) and the atmosphere.

EXAMPLE 3: The priming method of the invention: A number of drum devices of Example 1 or 2 were filled between 33% and 50% of the volume of the outer chamber (5, 14) with aqueous solutions of PEG (20,000 molecular weight) to give osmotic forces between - 0.6 and -1.9 MPa as appropriate. The respective chambers (6, 15) were filled with seed quantities depending on the capacity given in Example 1 and the ends sealed with the caps (4, 23) mounted on the gaskets (7, 22). The drums were placed with their lateral surfaces of the outer cylinder on the rollers of a Bellic cell production roller apparatus (see Figure 3) in a controlled temperature room at 15 ° C and rotated at 0.8 rpm for periods as described in Table 2 below. The water activity of the PEG solution was measured indirectly at set intervals, ie once a day, weighing without the seeds to determine the change in the water content of the outer chamber and adding water to restore the original weight and thus the osmotic pressure extracted. A computer program was used to operate the unit numbers simultaneously with the recorded details of each drum unit and a peristaltic pump was controlled to add the correct amounts of water; Potential water changes are recorded automatically.

The results obtained using this protocol are illustrated in Tables 1 and 2: Table 1 giving the priming conditions used for a range of seeds using the method of the present invention and Table 2 giving the results of the germination tests for these and "natural", that is, the unprimed seeds.

As the present method can be used by large growers of plants to grow indoor plants, a situation where the production follows a set plan and is not interrupted by bad weather, it was possible to consider the use of fresh primed seed ie without drying, which has a limited storage life as for some species, this produces a faster and more uniform germination. The execution of these seeds is also given in Table 2.

Re-drying after priming was carried out using standard techniques well known to those skilled in the art where required. - 2Í = days for germination Thus it can be seen from these results that the dried seeds of the Primula have been provided that are capable of germinating in six days or less while the dried seeds of Thought obtained are capable of germinating in 60 hours or months.

EXAMPLE 4. The germination method of the invention The method of Example 3 was used but the period for which the seed was treated was increased until at least some of the seeds showed signs of the emergence of the radicle. The seeds are then transferred to a device that classifies the seed of the type described by Kirin Brewery in JETRO May 1994 which was adapted by provision of the hollow projections of the rotating classifier drum. These void projections are dimensioned such as having an end diameter distant from the center smaller than the diameter of the seed and carrying the suction generated by the blower such as to be able to retain the seed when the drum rotates by passing a seed to the seed area. reception. The seeds taken to the drum were presented to a CCD camera which is used to provide a signal or group of signals indicative of the size of the seed and the color which is instead used to classify the seeds as germinated or ungerminated. The seeds classified as ungrouped are thrown by the purge nozzle and recycled to the primer treatment of Example 3, while those classified as sprouted are thrown to the separate position, i.e. by the brush for scraping, and further processed, is said drying, coating or restitution of the desiccation tolerance is re-dried by treatment in a drum device of the invention which uses a solution of predetermined osmotic potential such as to produce a water content of the seed between 35 and 55 % in weigh.

The criterion for the classification of the seed as germinated will conveniently include the presence of a lighter visible color on the surface of the seed due to the emergence of the radicle. The appropriate level of color difference can be conveniently determined by, ie, the discriminant analysis that the seeds of the known germination state use to establish the minimum values with a computer processor that computes these to store them in a memory device as it is known in the optical classifier art.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Having described the invention as above, property is claimed as contained in the following

Claims

1. A method of treating a seed to effect the control of its water content characterized in that it comprises the contact of the seed with a first surface of a semi-permeable membrane having the first and second surfaces, the second surface that is in contact direct with a solution of predetermined osmotic potential, such that the seed subtracts water from the solution through the membrane, wherein the seed and the semi-permeable membrane are constantly or periodically caused to move relative to each other such as either constantly or periodically the seed is reoriented with respect to the first surface such that the water transfer occurs evenly over substantially the entire surface area of the seed.

2. A method according to claim 1, characterized in that the method comprises the supply of the seed with water in a controlled manner.

3. A method according to claim 1, characterized in that it is a method for priming a seed, wherein the osmotic pressure and the period for which the seed is kept in contact with the membrane are sufficient to allow carrying out the processes pre-germinative metabolites within the seed up to any level until immediately before the emergence of the radicle.

4. A method according to claim 1, characterized in that this is a method for the germination of a seed, wherein the osmotic pressure and the period for which the seed is kept in contact with the membrane are sufficient to allow the seeds to be carried out. pre-germinative metabolic processes within the seed at least until the radicle emerges.

5. A method according to claim 1, characterized in that it is a method for the induction of tolerance and desiccation in a seed, where the osmotic pressure and the period for which the seed remains in contact with the membrane are sufficient to produce a level of water of the seed insufficient to support the growth of the radicle but high enough to allow other metabolic processes to continue.

6. A method according to claim 5, characterized in that the water level of the seed that is produced is from 35% to 55% by weight of the seed.

7. A method according to any of the preceding claims, characterized in that the semi-permeable membrane is provided in the form of a tube of polygonal or circular cross section that is rotated with the seed on its inner surface and the solution that is retained between its outer surface and an additional body to which the membrane is sealed in a water impermeable manner or of which the membrane is an integral part.

8. A method according to claim 7, characterized in that the semi-permeable membrane is such that, when the outer surface of the tube contacts the solution, the inner surface of the tube in visible form appears to be dry.

9. A method according to claim 7 or 8, characterized in that only the contact of the seeds, or some other absorbent body, with the first surface results in the transfer of water to the first side.

10. A method according to any of claims 7 to 9, characterized in that the tube is provided with end caps.

11. A method according to any of the rei indications 1 to 10, characterized in that the semi-permeable membrane is placed on a structure inside a drum device such that it divides the drum device into the inner and outer chambers which are isolated with regarding the transfer of water between the two different ones through the semi-permeable membrane itself.

12. A method according to claim 11, characterized in that the second chamber is completed by one or more different elements of the non-permeable wall that includes those on which the semipermeable membrane tube is mounted.

13. A method of conformance with any of the claims is precedent, characterized in that the semi-permeable membrane is made of any material that is permeable to water but impermeable to the predetermined osmotic pressure solution.

14. A method according to any of the foregoing claims, characterized in that the semi-permeable membrane is made of cellulose and / or polycarbonate materials suitable for dialysis.

15. A method according to any of claims 7 to 14, characterized in that the tube is rotated at about 0.8 to 1.2 rpm and the outer drum diameter is about 110 mm.

16. A method according to any of the preceding claims, characterized in that the osmotic potential of the solution is between -0.5 to -2.0 MPa.

17. A method of conformance with any of the claims is precedent, characterized because it is carried out between 10 and 25 ° C.

18. An apparatus for treating a seed to effect the control of its water content which comprises a semi-permeable membrane having the first and second surfaces, the first surface adapted to be in contact with the seed to be treated in use, the second surface that is placed in a chamber adapted to contain a solution of predetermined osmotic potential such as to contact the second surface, - 3í whereby in use the seeds are capable of subtracting water from the solution through the membrane and wherein the apparatus is adapted such that in use the first surface and the seed are caused to move relative to one another such that the seed is periodically or constantly reoriented with respect to the first surface according to which the water transfer is carried out evenly over its entire surface area.

19. An apparatus according to claim 18, characterized in that the semi-permeable membrane is provided in the form of a tube of polygonal or circular cross section which is rotatable such as to be able to carry the seeds er. its inner surface with the solution that is retained in the chamber which is formed between the outer surface and an additional body to which the membrane is sealed in a waterproof manner.

20. An apparatus according to claim 18 or 19, characterized in that the semi-permeable membrane is such that, when the outer surface of the tube contacts the solution, the inner surface of the tube appears to be dry.

21. An apparatus according to claim 18, 19 or 20, characterized in that only the contact of the seeds, or some other absorbent body, with the first surface results in the transfer of water to the first side.

22. An apparatus according to any of claims 18 to 21, characterized in that the tube is provided with end caps.

23. An apparatus according to any of the rei indications 18 to 22, characterized in that the semi-permeable membrane is placed on a structure within a drum device such that it divides the drum device into the inner and outer chambers which are isolated with regarding the transfer of water between the two different ones through the semi-permeable membrane itself.

24. An apparatus according to claim 23, characterized in that the outer chamber is completed by other non-permeable wall elements including those on which the semi-permeable membrane tube is mounted.

25. An apparatus according to any of claims 18 to 24, characterized in that the semi-permeable membrane is made of a material that is permeable to water but impermeable to the predetermined osmotic pressure solution.

26. An apparatus according to any of claims 18 to 24, characterized in that the semi-permeable membrane is made of cellulose and / or polycarbonate materials suitable for dialysis.

27. An apparatus according to any of claims 18 to 26, characterized in that the tube is mounted in a drum device which is mountable in a roller structure such that it can be driven to rotate.

28. The seeds characterized because they are Primrose, Sage or Thought in primed form.

29. The dried Primula seeds are characterized because they are able to germinate in six days or less.

30. The seeds of Dry Thought characterized because they are able to germinate in 60 hours or less.

31. A method according to claims 4 to 7, characterized in that the seed of the treatment is passed to a seed sorter and classified as germinated or non-germinated.

32. An apparatus according to any of claims 18 to 27, characterized in that it further comprises drive means for rotating the semipermeable membrane tube about its longitudinal axis oriented horizontally.

33. An apparatus according to claim 32, characterized in that the driving means comprise a driven roller structure.

34. An apparatus according to any of claims 18 to 27, 32 and 33 characterized in that it further comprises a seed sorting device. SUMMARY OF THE INVENTION A method is provided for the treatment of plant seeds comprising contacting them with a first surface of the semi-permeable membrane having the first and second surfaces, the second surface that is in direct contact with a solution of osmotic potential predetermined, whereby the seeds subtract water from the solution through the membrane, wherein the seed and the semi-permeable membrane are constantly or periodically caused to move relative to one another such as constantly or periodically the seeds reoriented with respect to the first surface such that water transfer occurs evenly over substantially the entire surface area of the seed. For seed priming the osmotic pressure and the period for which the seeds are kept in contact with the membrane are sufficient to allow the pre-germinative metabolic processes to be carried out within the seed to a limited level immediately preceding the seed. emergency of the radicle. Methods for seed germination and seed tolerance induction are also provided. Preferably the semipermeable membrane is provided in the form of a tube of polygonal or circular cross section which is rotated with the seeds on its inner surface and the solution which is retained between its outer surface and an additional body to which the membrane in a waterproof manner.