WO1994009612A1

WO1994009612A1 - A machine and a method for clearing and covering up seed potatoes

Info

Publication number: WO1994009612A1
Application number: PCT/DK1993/000340
Authority: WO
Inventors: Jørgen ØSTERGAARD
Original assignee: Samka Vejle A/S
Priority date: 1992-10-27
Filing date: 1993-10-26
Publication date: 1994-05-11
Also published as: DK130692A; NL192968C; GB9507437D0; DK167300B1; GB2286514B; NL192968B; DK130692D0; GB2286514A; NL9320047A

Abstract

The invention relates to a machine for use in connection with the lifting up of seed potatoes and the like tuber or root crops and to a corresponding method. The machine comprises a number of lifting shares (3) and at least one endless conveyor chain (4, 5) to be rotated by the driving means of the machine, for the clearing or lifting up of the potatoes (2), and a covering tool, especially covering discs for the subsequent covering up of the potatoes. Alternative embodiments of the machine further comprise a plough share (6) ploughing a groove, into which the potatoes are put down, and preferably additionally a down chute (8) for the potatoes. The machine preferably clears two rows of potatoes, putting them down into one central row. The machine is used to avoid the transmission via green flies of harmful virus to the seed potatoes, and in order to obtain suitably matured potatoes having a firm skin. Using the machine an environmental advantage is also obtained, since there is no need for the tops of the potato plants to be withered down using chemical sprays, and besides the whole sequence of operations of the process is streamlined. Finally, the tendency of black scurf is reduced.

Description

A Machine and a Method for Clearing and Covering up Seed Potatoes

The invention relates to a machine for use in connection with the lifting or digging up of seed potatoes and the like tuber or root crops, said machine comprising a number of lifting shares and at least one endless conveyor chain to be rotated by the driving means of the machine.

By "seed potatoes" is meant potatoes to be planted in the season to come.

The potato top is usually attacked by green-flies when these potatoes, usually at the end of July, have grown suitably big. These green-flies are harmful of several reasons, for instance they transmit undesirable mould species and virus, e.g. leaf roll virus and virus Y0, Yn, X, S and M, to the potato plant and consequently also to the seed potatoes.

According to the known art, this problem is solved by spraying with chemicals, i.a. with Reglone® manufactured by ICI comprising as the active ingredient diquat-dibromid, with so¬ dium chlorate or with Basta® manufactured by Hoechst comprising as the active ingredient glufosinat-ammonium. These crop sprays make the top of the plants wither down, following which the green-flies with accompanying harmful micro-organisms are of course no longer able to attack. Amongst the action mechanisms of the sprays, the production of hydrogen peroxide under the influence of the sun light is to be mentioned, said hydrogen peroxide killing the plants.

The spray Reglone® is at present subjected to further examinations concerning a possible ban on it's use. The spray Basta® is then the best alternative. Spraying therewith is disadvanta- geous, however, as no single leaf is allowed on the stem when spraying, because the spray would otherwise be transported into the tubers, following which the germination ability in the following year will be inhibited. Accordingly the top must have lost all it's leaves beforehand, which has far from occurred when the spraying is normally needed.

The spraying is disadvantageous of many other reasons. Primarily the environment is ad¬ versely influenced by the sprays, and besides lots of precautionary measures have to be ob¬ served during the spraying, i.a. one has to pay regard to the direction and the force of the wind, sun and rain. It would be rather nice to be independent thereof. When the top of the potato plant is withered down using chemicals, the stem does not turn soft, and the potatoes are accordingly not readily releasable from the top. When afterwards digging up the potatoes, problems arise due to both of the facts mentioned above. Besides there is a risk of the stem, after the spraying, when the withering-down has taken place too early, i.e. before the potatoes are fully developed, starting to set new leaves. The same problem arises, when the withering- down is made following a spell of drought. Finally problems arise following conventional spray¬ ing regarding bottom grass, meadow grass and the like, which is quickly growing up under the formation of cake units being very disturbing during the digging-up to follow. To remedy the lack of softness of the top after the spraying one, two or three further spraying rounds have been performed, this, however, in no way reducing the bad influence on the environment.

The correct maturing of the potatoes constitutes another, but associated problem. When the plant is still alive, the skin of the potatoes is very soft and is easily broken. When the top has withered, the skin is developing or maturing further, getting harder and stiffer in order to protect the potato against several deleterious influences. But the skin is best matured in the soil. So following the above-mentioned withering-down, according to the known art, the potatoes are left in the soil for 8-10 days before their digging-up, to guarantee the development of a desirable skin.

Another problem, however, is associated with the leaving of the potatoes in the soil. In the soil a parasite, the violet root rot or black scurf, is found, said fungus producing undesired sclerotia at the tubers, when these are no longer growing. The potatoes may be completely black due to these sclerotia. Therefore the potatoes should on the other hand be digged-up shortly after the withering-down.

All things considered at lot of problems are connected with the digging-up of seed potatoes, these problems, however, being considerably diminished when using the machine and the method of the invention.

According to claim 1 , the machine is characterized in further comprising a covering tool. Using the machine, the potatoes are simply cleared or laid open and afterwards re-covered, i.e. they are, in the same process, digged-up and immediately sowed again, using the same machine.

Thereby attacks by vira transmitted via green-flies are prevented, quickly and easily and with- out having to take into account the wind and the weather and without using crop sprays, and the potatoes are immediately re-sown, allowing for the desired maturing of the skin to take place. Besides weeds are separated and the seeds thereof covered, and so distinct cakes of weeds are prevented from having grown up by that time when the potatoes are digged-up.

Still further, it has unexpectedly become apparent, that the tendency to attacks by black scurf is considerably reduced using the machine of the invention, as compared to the withering-down. An essential difference between the two methods lies in the fact, that the potatoes, when cleared and re-covered, are more quickly separated completely from the top, from it's subterra- nean parts, too. This fact might influence thereon; the exact reason, however, is not known at present. Experiments show a reduction of the attack by black scurf of as much as 80% by clearing and subsequent covering-up. These experiments were conducted partly in a general lot, partly in an artificially infected lot.

Properly speaking a man of skill in the art has been aware that a digging-up of the potatoes would also prevent attacks by green-flies infested with micro organisms, this method, however,

^■ has not been introduced in the known art, because of the seed potatoes at that time having not yet matured satisfactorily for being digged-up because of their soft skin, cf. above. Alterna- tively, the potatoes could be left on the ground, but there they are exposed to the sun light and the rain, at the risk of becoming green and rotten, and as moreover the best maturing takes place in the soil, this alternative has to be rejected. As a last alternative, one might suggest to re-sow the potatoes. Using the known art, this operation, however, would be cumbersome and work-requiring, as one would in any case have to drive across the field two times, primarily with a lifting device and then with a ridging plough or something like that, moreover at the risk of the potatoes being not sufficiently covered. What is worse: The method does not work at all, be¬ cause the potatoes will turn soft when being covered after having been left for only a few hours on the ground, during which for instance all the potatoes in the actual field have been digged- up.

In claim 2 a special embodiment of the machine of the invention is disclosed, wherein at least one plough share is incorporated before the discharge end of the conveyor chain. During the forward movement of the machine, a groove is ploughed by this plough share, into which the potatoes are subsequently put down. Thereby the subsequent re-covering of the potatoes is optimised and facilitated, a complete re-covering of these with earth being very important. If the potatoes happen to end up outside the bank (of earth) or in the peripheral portion thereof they might on the one hand turn green and rotten because of the exposure to sun light and rain, and on the other hand they will be within the reach of birds and other animals, which might spread them at the risk of crossbreeding of sorts. The complete covering-up of the rest of the top is very important, too, as it might otherwise start growing again, and as it might stay stiff and hard, i.e. not turn soft. Having not turned soft, the stiff stems give rise to problems during the subsequent digging-up or lifting of the potatoes, and besides the potatoes will not be re¬ leased from their cord of connection to the plant just as quickly, with the consequence that the risk of attacks by violet root rot is increased.

In claim 3 a machine is disclosed, which further comprises a guide means for the potatoes at the end of the last conveyor chain. For instance this guide means is constituted by another conveyor chain being extended in an inclined direction as compared to the other conveyor chains, if desired perpendicular thereto, said guide means guiding the potatoes to the desired position. Preferably the machine comprises a down chute, guiding the potatoes down onto the ground in a row, especially down into the groove made by the plough share.

In the embodiment of claim 4, the covering tool being constituted by covering discs, an espe¬ cially preferred form of the bank is obtained, clods of earth being avoided and the bank assum¬ ing a quite sharp shape. This sharp shape is preferred, as it enables the rain to run off the bank, not down to the potatoes, where it might give rise to rot. Clods of earth, arising for in¬ stance from the use of a conventional ridging plough, are unwanted during the subsequent lifting of the potatoes.

In claim 5 a machine is disclosed comprising a down chute being covered by a 10 - 30 mm thick layer of spongy rubber coated by a 1 - 5 mm thick layer of wearing rubber. Hereby a protection of the potatoes against severe pushes and bumps is obtained, as well as a protection against tearing off the skin.

An especially advantageous embodiment of the machine of the invention is disclosed in claim 6, using which two rows of potatoes are simultaneously lifted, then re-sowed and re¬ covered into one row only. The machine comprises eight lifting plough shares being movable over a crank in a way known per se. Thereby a vibration is generated excellently preventing stops at the intake resulting from blocking up and the like. Besides the bank rolls known from potato lifters can be left out, these rolls lying closely down over the bank, guiding material towards the intake. The lifting plough shares pass the lifted-up material to a first conveyor chain, passing over to another subsequent conveyor chain. Using two chains in succession, among other things a better sorting out of clods of earth is obtained. This effect is further im¬ proved when the chains are subjected to a vibration. Guiding guard plates are placed beneath the chains, said plates collecting the earth falling down from the chains, thus making some more earth available to the covering discs for the final covering up. In this embodiment, the plough share is centrally placed beneath the second chain to position the groove for the re- sowing of the potatoes lifted from two rows centrally between the two original rows. The plough share is preferably adjustable in the height level allowing for adaptation to varying soil types and varying potato sorts; the sowing depth may vary. Besides, and preferably, the plough share is, in a way known per se, rotatably suspended at a pivot joint, enabling it to yield when running into too large-sized stones. The down chute is preferably coated by rubber or the like chock absorbing material, and the covering discs are preferably adjustable in height level and inclina¬ tion, still for adaptation to variable earth types and potato sorts. The method of claim 7 corresponds to the use of the machine according to claims 1 and 4, the method of claim 8 corresponds to the use of the machine of claim 2, and claims 9 and 10 correspond in the same way to claims 3 and 6.

In the accompanying drawing the invention is explained further. In the drawing

fig. 1 is a side-view of an outline of the principle of a preferred embodiment of the machine of the invention, and

fig. 2 is a top-view of the same.

Only the necessary and/or preferred tools or means are shown at the principle outline. For the sake of clearness the mutual connections thereof and the frame of the whole machine are deleted.

The machine has primarily been developed for use with seed potatoes, it is utilizable, however, for similar root crops, for instance onion sets. Besides it is advantageously used for certain forms of eating potatoes. In species like SAVA® the potatoes tend to grow up into the bank of earth, thereby turning green. Because of that up to 25% of these potatoes have to be sorted out following their digging-up. Of course the problem is worst when the top has withered down to no longer afford shade from the sun. In situations like these, the machine of the invention could advantageously be employed.

The machine of the invention works as follows:

Two or four rows 1 of seed potatoes 2, still carrying their top, are digged-up using a suitable number of lifting shares 3. If desired, the uppermost of the top has been cut off and put to the side beforehand, using a top cutting means mounted at the front of the driving means of the machine. When simultaneously clearing two rows, the number of lifting shares 3 preferably amounts to eight. In the embodiment shown the lifted-up material, i.e. potatoes carrying more or less of the top, stones, clods of earth and the like, is sliding from the lifting shares onto two conveyor chains 4, 5 in succession. A single conveyor chains is sufficient, as well as more than two are applicable, all dependant on the nature of the earth. An appropriate number of con¬ veyor chains is often two, taking into consideration the actual amount of earth and clods thereof being lifted up with the potatoes and having to be sorted out. The potatoes 2 may be put down directly onto the ground or preferably in a groove 7 ploughed therein using one or more plough shares 6. This groove may be arranged centrally as shown, or for that matter for instance to the side, too. A down chute 8 or another guide means, e.g. another conveyor chain, is guiding the potatoes 2 down into the groove 7, following which they are covered by a covering tool. In the embodiment shown, two covering discs 9 are used, every covering tool, however, is applicable, for instance a usual ridging plough. Anyhow, as mentioned above, coverings discs are pre¬ ferred.

Using the method and the machine of the invention, the environment is spared, as spraying with withering-down sprays is avoided, and a simpler treatment of the potatoes is obtained, inter alia because the treatment does no longer depend on the wind and the weather. Prefer¬ ably, the potatoes are left in the bank of earth for 8 days before their final digging-up, to permit the firm skin to be developed, but they may for that matter be left for up to 30 - 40 days without any problems arising relating to violet root rot or to something else, so all you have to do is to leave the potatoes in the bank, until their digging-up can be fitted into the working schedule. For instance one may, while no prerequisite, await fine weather. The capacity of the machine of the invention is fantastically big, between 3/4 and 1 ha per hour (1 ha = 10.000 m²) to be com- pared with the capacity of one-row potato lifters being typically about 3 ha per day (a 10- 12 hours).

Claims

PATENTCLAIMS

1. A machine for use in connection with the digging-up of seed potatoes and the like root crops comprising a number of lifting shares (3) and at least one endless conveyor chain (4, 5) to be rotated by the driving means of the machine, characterized in further comprising a covering tool (9) to subsequently re-cover the potatoes laid open or cleared at the ground or in the soil.

2. A machine according to claim 1, characterized in further comprising at least one plough share (6) before the discharge end of the conveyor chain (5).

3. A machine according to claims 1-2, characterized in further comprising a guide means for the potatoes at the end of the last conveyor chain (5), preferably a down chute (8).

4. A machine according to claims 1-3, ch a ra cte ri zed in that covering discs (9) are used as the covering tool.

5. A machine according to claim 3-4, characterized in that the down chute (8) is coated by a 10-30 mm thick layer of spongy rubber, said spongy rubber being coated by a 1- 5 mm thick layer of wearing rubber.

6. A machine according to claims 1-5 for use in connection with the digging-up of seed potatoes and the like, c aracterized in, for the clearing of two rows (1) of potatoes (2) and the subsequent re-covering thereof in one row, that it comprises eight lifting plough shares (3), being preferably movable over a crank shaft, two endless conveyor chains (4, 5) in succession just after the lifting shares (3) and intended for rotation and preferably vibration too by or via the driving means of the machine, some guiding guard plates beneath these conveyor chains, one plough share (6) placed beneath the second conveyor chain (5) approximately centrally in a direction perpendicular to the driving direction of the machine, said plough share being preferably suspended at a pivot joint and adjustable in the height level, a down chute coated with a layer of rubber placed at the discharge end of the second conveyor chain (5) and two covering discs (9), being preferably of adjustable height level and inclination.

7. A method in connection with the digging-up of seed potatoes or the like root crops, characterized in that the potatoes following their digging-up, in the same process, are put down onto the ground, the potatoes being finally re-covered using a covering means, pre¬ ferably covering discs.

8. A method according to claim 7, characterized in, that the potatoes after their digging-up are put down into a groove, preferably a central groove, before their final covering- up.

9. A method according to claims 7-8, characterized in, that the putting down of the potatoes at the ground or into the groove is guided, preferably using a chute down.

10. A method according to claims 7-9, characterized in, that two rows of potatoes are digged-up simultaneously and subsequently put down into a central groove, which is finally covered by earth to produce a bank of earth, which is quite sharp.