IE892186L

IE892186L - Seed germination apparatus

Info

Publication number: IE892186L
Application number: IE218689A
Authority: IE
Original assignee: Multigerm International Ltd
Priority date: 1988-07-07
Filing date: 1989-07-06
Publication date: 1990-01-07
Also published as: GB9100106D0; GB8816228D0; WO1990000345A1; GB2238458A; IE60154B1; GB2238458B

Description

6015 4 This invention relates to a seed germination apparatus and method and in particular to a seed germination apparatus and method which provides a repetitive cycle of immersion in water and 5 ventilation in air.

It is well known that extreme care is required during the germination of seeds to preserve the seeds' quality and ability to perfom well. In particular, seeds must not only not be injured during 10 germination processing, but they should also enjoy optimal environmental conditions, in particular exposure to appropriate quantities of water and air. A variety of other environmental factors may also have to be taken into account. For instance, optimal 15 conditions of temperature, light, absence of pathogens are also desirable. They are not, however, the subject of the present invention and will not be further discussed herein.

A known seed germination apparatus comprises a 20 chamber in which seeds are fully immersed in water. Compressors are provided which bubble air up through the water, individual seeds being lifted up on the bubbles of air. Consequently, the air lift mechanism provides both redistribution of seeds, which is 25 desirable since it prevents injury to seeds through them compacting, as well as some exposure to air.

After a period of redistribution, the chamber is drained of water and a ventilator switched on to expose the seeds to air. After this ventilation 30 period the chamber is subsequently filled with water again so that the seeds are fully immersed and the compressors switched on again to provide further redistribution. Redistribution between the ventilation periods with the chamber drained is 3 essential to ensure that seeds which may be in areas receiving less ventilation are circulated to areas receiving more ventilation. Uniformity of germination is highly desirable and can only be 5 achieved if all seeds receive similar levels of ventilation and water. This cyclic process continues until desired germination throughout the batch of seed has taken place.

There are significant disadvantages to this 10 approach, however. For instance, the requirement for the repetitive drainage and filling of the whole of the chamber with water means that this approach is not only slow but requires a great deal of water. In countries in which water is scarce, the dependence on 15 water can be inconvenient and expensive. A further drawback is the time it generally takes to fill up the chamber prior to switching on the compressors. This may lead to unsatisfactory swelling of some seeds.

It is an object of the present invention to provide a seed germination apparatus which is both economical in the use of water, allows more rapid processing to germination, and is easily automatable.

In accordance with the present invention, a 25 seed germination apparatus comprises a germination chamber for containing a batch of seed and means arranged to circulate seed from a region in the chamber which is wet during circulation to a region in the chamber which is substantially dry during 30 circulation.

The apparatus preferably also comprises a fluid supply means adapted to supply to the chamber a predetermined quantity of fluid which is sufficient to immerse only 35 a portion of the batch of seed to thereby provide the said region in the chamber which is wet.

By arranging for only the partial filling of the chamber with water, the present invention is more economical in its use of water. Furthermore, the time taken to only partially fill the chamber will clearly be less than that required to completely immerse all the seed. Consequently, the delay between starting to fill the chamber and commencing circulation is greatly reduced, resulting in considerably shorter processing cycles. This not only provides more rapid germination, but also more even germination through the batch.

In addition, the means arranged to circulate may preferably comprise a seed and water conduit disposed externally of the chamber. By arranging for such an external circulation of the seed, the controlled application of additives to the water is facilitated since such additives can be fed to the conduit circulating the water and seed mix. This application technique may result in a more uniform exposure of seed to those additives, which may commonly be hormonal dormancy requlators, growth regulators and protectants.

In accordance with another aspect of the invention, a seed germination method comprises the steps of filling a germination chamber with seed to a given level; filling the chamber with water to a second given level so that only a portion of the seed is immersed and circulating seed taken from said portion to a region of the chamber not immersed.

The. invention will be described in detail with reference to the accompanying drawing which is a schematic illustration of a seed germination apparatus exemplifying the present invention.

Referring now to the figure, a germination chamber 1 is shown. The chamber is shaped as an inverted cone, having walls sufficiently sloping to prevent the formation of seed bridges inside the chamber. An exit from the chamber is provided at the apex of the cone, at which are provided valves 2 which permit either only water or a seed and water 5 mix to be drawn off. Valves 2 are connected via conduit 11 to the low pressure side of a pump 3 which can pump a seed and water mix without damaging the seed. The pump 3 may be, for instance, a diaphragm or venturi type pump. The high pressure side of pump 10 3 is connected by a further conduit 11 to an outlet means 4 adapted to spread the seed over the top of the seed 10 already in the chamber 1. The outlet means may, for instance be sprinkler system. A further outlet to pump 3 is provided which is 15 connected via a conduct 5 to a bagging hopper or further treatment chambers (not shown).

A ventilator 7 is connected to a ventilation point 6, the latter being positioned inside the chamber 1. A fluid supply means 9 is provided to 20 supply fluid, generally water, to the chamber 1.

The operation of the seed germination apparatus may be understood as follows.

Initially, the chamber 1 is filled with a batch of seed to a given level, as depicted in the 25 accompanying figure. Fluid, which will be referred to as water hereinafter for ease of comprehension, is then pumped by the fluid supply means 9 into the chamber 1 to cover all the seed, which is then allowed to soak for a predetermined time. The water 30 is then drained from the chamber 1 via valves 2 to a store (not shown). Water from this store may be re-used during subsequent processing.

The ventilator 7 is then operated to provide additional ventilation of the seeds with air. 35 Subsequently, water is fed into the chamber from the supply means 9 up to the level 8. Consequently, only a small fraction of the seed is actually immersed. The region in the chamber which actually contains water, i.e. that below level 8 is defined as the "wet region", conversley, that above the water level 8 is defined as the "dry region". The pump 3 is then activated to start circulating the seed fed from the apex of the chamber 1, i.e. from the wet region, via conduits 11, and the sprinkler 4, to the top of the seed pile, i.e. to the dry region. Circulation continues for a given time, after which the chamber may be drained, and the ventilator 7 is turned on again. After a given period of ventilation, the chamber may again be filled with water to the level 8 from the supply means 9 to replenish water taken up by the seed. Recirculation then recommences. The entire cyclic process is continued until adequate germination has been achieved. 7

Claims

CLAIMS;

1. Seed germination apparatus comprising a germination chamber for containing a batch of seed and means arranged to circulate seed from a region in 5 the chamber which is wet during circulation to a region in the chamber which is substantially dry during circulation.

2. Seed germination apparatus as claimed in Claim 1 further comprising fluid supply means adapted 10 -to supply to the chamber a predetermined quantity of fluid which is sufficient to immerse only a portion of the batch of seed to provide thereby the said region in the chamber which is wet. 15

3. Seed germination apparatus as claimed in either Claim 1 or Claim 2 wherein the means arranged to circulate comprises a fluid pumping means capable of pumping a seed and water mix without damage to said seed. 20

4. Seed germination apparatus as claimed in any preceding claim wherein the means arranged to circulate comprises a seed and water conduit disposed externally of the chamber.

5. Seed germination apparatus as claimed in 25 any preceding claim wherein the walls of the chamber are sufficiently sloped to prevent the formation of seed bridges inside the chamber. 30

6. Seed germination apparatus as claimed in any preceding claim further comprising air supply means adapted to provide additional ventilation for the seeds in the chamber.

7. Seed germination apparatus as claimed in any preceding claim wherein the means arranged to circulate seed comprises an outlet means adapted to spread the seed in the said region which is substantially dry.

8. Seed germination apparatus as claimed in any preceding claim further comprising feed means adapted to supply seed to a bagging hopper.

9. Method of germinating seed comprising the steps of filling a germination chamber with a batch of seed to a given level; filling the chamber with water to a second given level so that only a portion of the batch of seed is immersed and circulating seed taken from said portion to a region of the chamber not immersed.

10. Method of geminating seed as claimpd in Claim 9 further coqacising the steps of draining the chamber of water and providing additional ventilation of the batch of seed.

11. Method of germinating seed as claimed in Claim 10 wherein the step of providing additional ventilation is carried out after a predetermined duration of circulating the seed.

12. Method of germinating seed as claimed in any preceding method claim comprising the further step, after a predetermined duration of circulating the seed, of filling the chamber with water to a given level so that only a portion of the batch of seed is immersed. 9

13. Method of germinating seed as claimed in any preceding method claim comprising the steps, prior to filling the chamber with water to a second given level, of filling the chamber with water so that substantially all the seed is immersed; allowing the seed to soak for a predetermined time; and draining the water from the chamber.

14. Method of germinating seed as claimed in , Claim 13 comprising the step, after draining the * vater from the chamber, of providing additional ^ventilation to the seed.

15. Seed germination apparatus substantially as hereinbefore described with reference to the accompanying drawing. F. R. KELLY & CO., AGENTS FOR THE APPLICANTS.