US2656649A - Seed pellet - Google Patents

Description

starch serving" to" bind the inert material.

Patented Oct. 27, 1953 SEED PELLET Marius HJOstier, Mereville} France .1 Ithas*"alreaidy beenproposed td impart a'pill shape, *by-means--=of a coating "basdwirgypsum plaster, to beetroot seeds;particirlarly-=seeds='hav- '"ing one germonly. Such pil1s,*'which--are*of=a relatively smalldiameter; present 1 inter alia the disadvantage that,nctwithstandi-ngthethinness --of thecoating, it prevents germination on account of' its imperviousness to water and/or its resistance which the germ is unable to overcome sup- "posing it has been able to develop.

The 'inain objectof this inventionis t-o-provide acoating or'artifici'al hull'which is capableof fulfilling the three following conditions together:

(1) *It is of a 'jconsistency which enables the seed to germinate"withoufihirfdrance" and at the proper time.

(2) "Itissufficientlyresistant not to be broken in the course of thevariousmanipulations (coating, 'transport placing in the sowing machine) (*3) It is -'proof--against"any variation of temperature-"and atmospheric moisture.

"The'coatingor artificial hull according to this inventiommay-comprise 'a 'base-"of inert material such as sand, sandstone;peat,loamenthelike, and a binder such as a glue oradhesive based on Said inert base may be-either-in the natural state 'orucrushed. The crushing of the base may be carried on down to any granularsize, but it will obviously be continued so far and the crushed grains will be much 1 smaller as it is desired to obtain pills of greaterresistance or f of smaller diameteryor as it is desired to use a smaller quantity of binding material.

Furthermore, "the "binder used to bind the grains of the base, instead of being-a starch glue *may also'beany vegetable" glue or other adhesive,

=such as paste, gluten andgelatine glues; provided it be imputresc'ible-and capable'of swelling under the influence of and being permeated through' by water. A carbohydrateglue such as starch, paste or gluten glue is particularly-desira'ble. In fact, it is important that, whenthe pill is deposited ina *sufiiciently moist soilfthe coated seed shouldbe subjected "to the "action of 'moisture from the ground to bring the-germinationabout, arid that, owing tothat'moisture, the coating should lose enough of,its.resistance to enable the germ to overcome it anddevelopnormally'inthe'soil.

The glue or ar'slhesive.:use'd asza'tbinder may be rendered imputrescible by anytknown process and -.it-may.,be: applied in a formlother thanpowder, zand intparticular be made'to swell or Joe-diluted in a suitable solvent, such as. water, for instance.

By way of example, the invention may 'be carried out as-hereunder.

Atpaste is made compose'dnas follows:

i (a) Links. of fine sand sucmas quarryrssa'n'd.

(ohm-s1 1 b) 1 A liqtiid glue or aidhesiveproducedby 'dililting theoold -state in 200 ccs. 0f water, "grams of g-lue in pow-denser fiakes -wit-h a -starch base as-sbld commercially under "the'namelof glue 5 300? T-he liquidrgl-ue-so -pro'duced is-poured into a vessel containing the sandand these ingredients are stirred together -50 as 'to produce: a homogeneous "paste.

-sa-fd paste is then-used in the manner known 1 -in the manufacture" of: pills l in -order I to coat the seeds,' *a1id=the pills are, of course dried before use.

The pills may be' ofaany diameter. Tests have shownthat even with an excessive diametersuch 'as 4" cm, for instancewhere the' seeds -are'mcnogerm beetroot-seeds, the'germination is 'nct prevented. "The: preferre'd diameter for 'the pills is 'a;bout 8"-m-m. It is also pos's'i'ble, whilst the paste is being prepared, to incorporate any insecticide or other suitable matei'ial-with the pastegfor "example in *order *to promote 'germination, or

the "finished *pi'll *may also be coated with -a further layer on said 1 insecticide or material.

"The invention also" relates to calibrated pills in which the *coa'ting-presentsa certain' elasticity,

Another 1 obj ect-jzof :the: invention is 2 toproduce 'fstratified r coatings, mamely coatings in which each zconstituent :is distributed :in a coat rsur- "rounding'eitherqthexseed itself or a previous :coat. nsfurthenobjectisito; produce seeds: covered :over

with coating films of a thickness variable was desired; including -veryi thini fi1ms,- .or+ with films i havinga specificz-gravities whicharcannbe controlled at will in the process.ofsproduction, wherebylit -isspossible;interealiafinally to. obtaim pills "which .wvhentheyiarezsownHarenotzaifectedrby windltoran .zlappreciablefdegree.

rAccordingiito:thatcaspectrofttheiinvention, the :coatingccomprises anaturalzor artificial,:resi1ient material which his finer-t atom/wardsthe :seed v :or at least does not attack therseed. Sucht'resilient material can,:inrprinciiplegmbe.aapplied asna layer, it" iscsufiicientlysfiuidcor ifi it hasnbeen "fluidised, "but :m-ore :zgeneraliy, 1 a :so'lid rmaterial is I resorted itoflwhich isitheniiprferablyi appliedi'iinl a granulan=1orzpowderyistate aas,:iorl.instance% inr'the form aomsittedgrasped,agnoundiomcmshed material. rAs

an example of natural materials, there may be mentioned in the first place cork, which offers the advantage that it can be obtained very easily and at a very low price and that it possesses a great elasticity, even in minute particles. There may also be mentioned other ligneous or cellulosic materials such as ground straw, refuse of elastic textiles, crushed peanut hulls, sawdust, and the like. As an example of artificial and natural materials which are not cellulosic and not ligneous there may be mentioned elastomers and particularly elastoprenes (rubbers and related substances) which are endowed with sufficient elasticity. Natural materials of mineral origin such as asbestos may also be used. In this connection all natural or artificial materials available as a resilient fiber padding may be resorted to. In principle, it is not necessary, although in many cases it is advantageous, to introduce also a dense ingredient in the coating composition for the purpose of giving weight to the finished pills.

According to the invention, the constituents of the coating compositions may also be applied either individually or in groups and in rotation, by suitably measured amounts, in the form of a spray or shower of minute particles upon the seeds subjected to a continuous stirring motion, as produced, for instance, in spherical containers in the production of sugar coated pills. For that purpose, a binder, preferably starch glue, is first sprayed in and, as the case may be, further binder material is again sprayed in after several other constituents have been sprayed in.

For example, if the binder is the only liquid constituent, said liquid is sprayed in the form of a sprinkle or a fine spray alternately with the dusting in of the other ingredients.

The application of the above methods will be illustrated by the following example which relates to the coating of beetroot seeds previously split up so as to form seeds having one germ only, and to the use of cork as resilient material.

Example to which had been added 20 grams of gluten glue sold on the market under the name of N L T glue was sprinkled on said seeds. As soon as the seeds appeared to be on the point of becoming agglomerated, that is to say when 300 cos. of liquid had been atomised, the whole mixture was sprinkled with 250 grams of fine sand (Fontainebleau sand). Such sand adhered to the glue coated seeds and isolated them from one another.

The same operation (atomising and powdering) was continued until 2.750 kilos of sand had become glued to the seeds.

The coated seeds were removed from the container then sifted through a sieve with circular meshes of 3.75 mm. The seeds which passed through the meshes were put back in the spherical container in which a binder and then sand as before were sprayed in until all the seeds could be retained by the sieve.

All the seeds were then placed in a larger spherical container in which alternately 300 cos. of water glued as before were atomised and 40 g. of cork flour were sprinkled. This operation was repeated several times until the balls thus formed were retained by a mm. mesh screen,

d whilst the smaller ones were returned to the container to be coated again as in the case of the sanding operation.

The balls formed in this way are dried, for example in a hot air rotary drier, the temperature of the air not being allowed to exceed 80, so as not to destroy the germinative capability of the seeds. The balls when finished are of a diameter varying between 4 and 5 mm. where the seeds are monogerm beetroot seeds.

The object of the sanding operation is to add weight to the balls so as to allow a more uniform sowing. In the case of certain seeds other than beetroot seeds and also in the case of certain sowing machine, such operation is not necessary.

Coating with cork or like resilient material imparts to the seed a resiliently flexible film which facilitates transport without any special packing. Moreover, a film having thickness as low as a few tenths of a millimeter although being quite adhesive can be put on the seeds. In any case the seed retains all its germinative vigour.

As above stated, the coating may contain inside 7 and/or on the surface thereof, adjuvants such as fertilisers and other growth stimulating products.

While for the sake of convenience, reference has been made to beetroot seeds, this invention is not restricted to beetroot seeds as will readily be realized. It has been found in particular that very good results were obtained in coating cotton seeds with their fibers, with films of the type above described, particularly films containing powdery cork or like resilient material; it is desirable to incorporate an anticryptogamic or seed dressing substance such as an organic mercury compound, in the coating, at least in a final film around an underlying film which contains powdery cork or the like. Coated cotton seeds having an average diameter of about 1 to 2 centimeters were found convenient for use.

What I claim is:

l. A seed pellet which comprises a seed encased in a body of a water-permeable binder adapted to be swollen by water, said body containing particles of cork disseminated at least in its outer portion.

2. A seed pellet which comprises a seed encased in a coating of fine cork particles and a starch glue holding said cork particles together. I

3. A seed pellet which comprises a seed encased in a coating comprising a water-permeable binder adapted to be swollen by water, particles of an inert material of higher specific gravity than the remainder of the coating, disseminated in said binder in the inner portion of said coating, and cork particles disseminated in said binder, in the outer portion of said coating.

4. The seed pellet of claim 3, said inert material being sand distributed in a substantially spherical inner layer of said binder, while cork particles are distributed in a substantially spherical outer layer of said binder.

MARIUS H. OSTIER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 56,140 Blessing July 3, 1866 2,083,065 Heyl June 8, 1937 2,313,057 Fischer Mar. 9, 1943 FOREIGN PATENTS 7 Number Country Date 36,846 Norway Feb. 19, 1923