AU741233B2 - Encapsulated fertilizers - Google Patents

Description

WO 99/07654 PCT/IL98/00322 1 ENCAPSULATED FERTILIZERS Technical Field The present invention relates to controlled-release encapsulated fertilizer.

More particularly, the present invention relates to a controlled-release encapsulated fertilizer comprising a core containing at least one fertilizer and a polymeric envelope containing at least one hormone encapsulating said fertilizer Background Art The encapsulating of various chemical reagents, pharmaceuticals, pesticides and herbicides in general have been proposed and described in the prior art.

As described e.g. in U. S. Patent 4,417,916, aqueous dispersions of pesticide and herbicide micro-capsules are particularly useful in controlled release pesticidal and herbicidal formulations because they can be diluted with water or liquid fertilizer and sprayed using conventional equipment, thereby producing uniform field coverage of the pesticide or herbicide/additives such as film forming agents can be added directly to the finished formulation to improve the adhesion of micro-capsules to foliage. In some cases, reduced toxicity and extended activity of encapsulated herbicides and pesticides have been noted.

A variety of techniques have heretofore been used or proposed for encapsulation purposes. In one such process, known as "simple co-acervation", a polymer separates from a solvent solution of the polymer by the action of a precipitating agent that reduces the solubility of the polymer in the solvent a salt or a non-solvent for the polymer). Patents describing such processes and their shell wall material includes U. S. Patent Nos. 2,800,458 (hydrophilic colloids); 3,069,370 and 3,116,216 (polymers); 3,137,631 (denatured proteins); 3,418,250 (hydrophobic thermoplastic resins); and others.

Another method involves micro-encapsulation based on in situ interfacial condensation polymerization. British Patent No. 1,371,179 discloses a process which consists of dispersing an organic pesticide phase containing a polymethylene polyphenyiisocyanate or toluylene diisocyanate monomer into an aqueous phase.

The wall forming reaction is initiated by heating the batch to an elevated temperature at which point the isocyanate monomers are hydrolyzed at the interface to form amines, which in turn react with unhydrolyzed isocyanate WO 99/07654 PCT/IL98/00322 2 is the possibility of continued reaction of monomer after packaging. Unless all monomer is reacted during the preparation, there will be continued hydrolysis of the isocyanate monomer with evolution of CO2, resulting in the development of pressure when the formulation is packaged.

Various methods of encapsulation by interfacial condensation between direct-acting, complimentary reactions are known. Within these methods are reactions for producing various types of polymers as the capsule walls. Many of such reactions to reproduce the coating substance occur between an amine, which must be of at least di-functional character and a second reactant intermediate, which for producing a polyurea is a di-functional or polyfunctional isocyanate. The amines chiefly used or proposed in these methods are typified by ethylene diamine, having at least two primary amino groups. U. S. Patent No. 3,429,827 and U. S.

Patent No. 3,577,515 are illustrative of encapsulation by interfacial condensation.

For example, U. S. Patent No. 3,577,515 describes a continuous or batch method which requires a first reactant and a second reactant complimentary to the first reactant, with each reactant in separate phases, such that the first and second reactants react at the interface between the droplets to form encapsulated droplets.

The process is applicable to a large variety of polycondensation reactions, to many different pairs of reactants capable of interfacial condensation from respective carrier liquids to yield solid film at the liquid interface. The resulting capsule skin may be produced as a polyamide, polysulfonamide, polyester, polycarbonate, polyurethane, polyurea or mixtures of reactants in one or both phases so as to yield corresponding condensation copolymers. The reference describes the formation of a polyurea skin when diamines or polyamines ethylene diamine, phenylene diamine, toluylene diamine, hexamethylene diamine and the like) are present in the water phase and di-isocyanates or polyisocyanates toluene diisocyanate, hexamethylene diisocyanate and polymethylene polyphenylisocyanate) are present in the organic/oil phase.

Several methods for coating fertilizers of such as KNO 3 and NPK have been known. Until 1981 one patent by "Sierra" disclosed the coating of osmocote (NPK).

After 1981 Japanese patents Nos. 84-146,053 and 54-840,716 disclosed coated fertilizers, said fertilizers were coated with urea formaldehyde.

-3- JP 63-162,593 discloses a fertilizer envelope.' Said envelops is produced by spraying a solution of polyethylene and eva (ethylene vinyl aromatic) in C01 2 =CC1 2 on fertilizer granules.

The world's nursery industry utilizes numerous products and techniques in order to maintain and produce millions of ornamental plants and fruit trees. The nursery industry uses sophisticated agrotechnologies and consumes large quantities of rooting stimulators. There is an ongoing need for novel products that could increase rooting percentages of difficult-to-root (mainly woody or semiwoody plant species) plants. There is also the need for improving the growth rate and quality of the plants produced by the nurseries.

A common procedure in a nursery entails the sporadic addition of fertilizers and hormones to the roots of new cuttings. The present inventors have found that the addition of a controlled-release encapsulated fertilizer can maintain the presence of the necessary compounds for the entire period of rooting and development of rooted plants.

Throughout the description and claims of the specification the word "comprise" and variations of the word, such as "comprising" and "comprises", is not intended to exclude other additives, components, integers or steps.

The discussion of the background to the invention herein is included to 20 explain the context of the invention. This is not to be taken as an admission that any of the material referred to was published, known or part of the common °o general knowledge in Australia as at the priority date of any of the claims.

Disclosure of the Invention 25 With this state of the art in mind, there has now been found, according to the present invention, a controlled-release encapsulated fertilizer comprising a core containing at least one fertilizer and a polymeric coating containing at least one plant hormone encapsulating said fertilizer.

In preferred embodiments of the present invention said coating contains at least one plant hormone selected from the group consisting of indole alkyl acid; indole acetic acid (IAA); indole propionic acid (IPA); indole butyric acid (IBA); 2,4 dichlorophenoxy acetic acid; 2,4 chlorophenoxy propionic acid; 2,4 dichlorophenoxyacetic acid propyl ester; and, naphthalene acetic acid.

3a In another embodiment of the present invention there is provided a process for encapsulating a fertilizer comprising: a) coating a fertilizer with a mixture of a first monomer and a plant hormone; b) adding a mixture of a second monomer and an additional hormone; and, C..o e c) heating said mixtures to induce the polymerization of said first and second monomers to form a polymeric coating incorporating said hormone and encapsulating said fertilizer.

wherein said coating contains at least one hormone selected from the group consisting of indole alkyl acid; indole acetic acid(IAA); indole propionic acid(IPA); indole butyric acid(IBA); 2,4 dichlorophenoxy acetic acid; 2,4 chlorophenoxy propionic acid; 2,4 dichloro phenoxyacetic acid propyl ester; and, Naphthalene acetic acid.

wherein said polymeric coating is formed by a polymer selected from the group consisting of polyurethane; polyurea; and, polyolefins.

While the invention will now be described in connection with certain preferred embodiments in the following examples so that aspects thereof may be more fully understood and appreciated, it is not intended to limit the invention to these particular embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the scope of the invention as defined by the appended claims. Thus, the following examples which include preferred embodiments will serve to illustrate the practice of this invention, it being understood that the particulars shown are by way of example and for purposes of illustrative discussion of preferred embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of formulation procedures, as well as of the principles and conceptual aspects of the invention.

Description of Preferred Embodiments Examples: A series of formulations were prepared according to the present invention.

As stated, according to the invention the fertilizer is the core of the formulation and the hormone is incorporated in the envelope. The hormones that were incorporated in the slow release formulations were from the following families: Auxin- Indole alkyl acid IAA (Indole alkyl acid), IPA (Indole Propionic Acid) and IBA (Indole Butynic Acid) LA 2,4 Dichlorophenoxy acetic acid S2,4 Dichlorophenoxy acetic propionic acid Sj AMENDED SHEET

IPEA/EP

WO 99/07654 PCT/IL98/00322 2,4 Dichloro phenoxyacetic acetic acid propyl ester Naphthalene acetic acid (NAA) auxin stimulated root regeneration and development Triazole Paclobutrazole (growth retardant that has an antigibberllin-enhanching effect on stimulation of root formation and increasing survival of rooted pland grown in stress conditions.

Cytokinine Benzoyladenine (plant hormone that stimulates development and branching of shoots) The coating consists of the following families of polymers: polyurethane polyurea polyolefis (like polyethylene) etc Carbohydrates such as sucrose, starch, etc. that are enhancing auxin effect on stimulation of root regeneration and development are added to the envelope. Other materials that are added to the formulation are to increase the nutritional content (micro elements such as: Fe, B, Mg, Zn, Mn, Ca, Mo, etc.), to increase biotic tolerance (Benedate), Falpane, Merpan, Prochloraz, propionazol, diazinone, nephorex, etc), and to increase a biotic tolernace of the plants (triazole compounds such as majic that increase drought resistance by stimulation of wax cover of the leaves).

The above mentioned hormones increase the rate of cell division and differentiation and the result of said increased rate is a stimulation of root regeneration and development.

Growth retardants such as Triazole e.g. paclobutrazole can also be added.

Said retardant has an anti-gibberllin-enhancing auxin effect on stimulation of root formation. Other materials that are added to the formulation are to increase biotic (pathogens) and abiotic (drought) tolerance of plants.

Hormones can also be added to the core if desired.

Procedure: The granules of fertilizer were put in a coating pan and one monomer withpart of the hormone was added. The coating pan rotated until the granules were WO 99/07654 PCT/IL98/00322 6 covered with one monomer containing part of the hormones, then a second monomer with the rest of the hormones and catalyst were added. The coating pan rotated and the mixture was heated up to 50 When the condensation polymerization ended, and when the granules are not sticky, talcum was added followed by melted wax. The coating pan was rotated continuously. The formulation is then put in bags.

The formulations are summarized in Table 1: Trable I Envelop formulation on fertilizer (KNO 3

MKP)

Example No. Amnount Amount Glycols I loriiones Extrusion KNO3, 9 Voranate tgI.ype Amount, type amuotimt 1Talc, g Wax, g Tertilizer Polye- I,,tthylene 1 (Al) 2. (A12) 3. (A2) 4. (A22)

(VI)

6. (1312) 7. (132) 8. (1322) 9. (ClI) (C2) 11. (C22) 12. (D 1) 13 (D2) 14. (E03) (Eli) 16. (E12) 17. (E342) 18 (E3112) I'EG-60() l'EG-60() PEIG-60() PEG-600 l'EG-1000 PEiG-1000 PEG-1 000 PEG-lOCO I'EG-6000 ITIG-6000 PEG-6000 I'Eg- 1 2000 PEG-1 2000 2-41V1 2-410) 2-413 2-4D) 2-41V1 2-41Vl 2-4D 2-41.) 2-4 D 2-4131' 2-41)1' 2-41)1' lIDA 2-4DIP 10 10 19. (13512) 25g+ 25 g 2 41A' lvi K P (E3532) 25g IDA 0.5 50 MvKI' 21. 100 5 E I) A+ 1.)IETA 03-10.7 IDA 0.1 15 10 +0.2g 1120 22. 100 4 Ii-DA+D''A 11.1 2-41) 1 10 0.5g 1120 Trable 1 (coajt) Example No. Amount Amnt11 Glycols I lormonles KNO3, g Voraia te Type AMOun1t, type amotint Talc, g Wax, g Fertilizer Polye- M580, g 9thylene 0/ 23. (111) 24. (1 V)

(V)

26. (V 1) 27. (VII) 28. (GSK-l) 29. (GSK-2) (GSK-3) 31. (GSK-5) 32. (GSK-6) 33. (GSK-7) 34. (GSK-8) (GSK-10) 36. (GSK-9) 37. (GSK- 11) 38. (GSK- 12) 39. GSK-13) (GSK-14) 41. (GSK-15) 42. (GSK-16) 43. (GSK-17) 44. (GSK-18) (GSK-19) 46. (GSK-20) 47. (GSK-21) 48. (GSK-22) 13DA*.* 1)1 A EDA-PD1 I'A I3DA +DI3'A E-I)A+DE)131A ED1A iDIA IAi+l-)E*IA I-DA IDETA EllA- DE IA EllA .DElTA IiDAiI)ETA EI)A+±DET A lEl)ADE-l1A IiDA-l)1'TA EI)A+D3FA E'DI)AfDETiA EIJAi D~ .ETA EDA I)EIA EDA-I DETA I-iDA4+D[-IA ED'lA+ ElA I )13A EIA EI)A+lJ I'A

PI)A+DE"T~IA

EllA I DETA +1)1liI[A EI)A i-DETA 0.81 0.7 14+1 1+1 1 +1 I1i-1 2.5-12.5 2.5+2.5 3+-3 2.5 12.5 34.3 30.

0.5M.5 I'B-zol

NIKI'

2-4-1)1' 2-'l-DI)' 2-4-Di) I'II-zol 2.41) 2-4D PBl-zol 2-4 IN1' 2-41Dl'+ I'13-zol 2-41)1 PII-zol 2-4 Dl)- 1'13-zol I-I BA l-zo14l BA I'B-zol I'I1-zo1+IiBA +2-4DI I'I)-zo+II BA +21)1' I'l3-zcol+ IIA+2V1' I BA+4P Il-zol +2 DP I BA -iI'I-zoI I hA -'1-z014i21)11'

GA

3 PBI-ZOLi 11SA I IIA-ig.I'I1-zol I BA 4-I3-zol II3A=I'I1-zoI 0.3g 1120 0.1 0.1 0.54 15 15 15 15 0.5-10.5 5 5 0.5-10.540.5 5 0.5-10.5 5 0.5 0.5+0.5 10.5 1.25-11.25-1-1:25 1.25+1.25+1.25 25 1.25+1.25+1.25 25 0.64-0.6 0.6+0.6+0.6 0.61 0.6 0.5 5 0.5 10.5 5 10 0.5 t0.5 5 5 0.540J.5 5 5 U.5+0.5 5 5 0.05 g 0.05 g 8 g Ilenlate 2 g Ikilpa..e 2g Merpaai 2g Prochimraz Iuu Table I (cont.) Exanple No. Ainouii Aiuil Glycls I 1lles

KNO

3 g Voraiiate I580, g 9 Iltylene 49. (GSK-23) 100 10 EDIDlTA IiI I BA I 1PH-zol 0.5 f 0.5 5 5 2 g I'opiutiazol (GSK-24) 100 10 EDA) ID'A 0.5-10.5 5 5 2 g Diazinonie 51. (GSK-25) 100 10 EI)A f DETA 0.5 10.5 5 5 5g 'liCo 52. (GSK-26) 100 10 E)AI*DE-TA 0.5 10.5 5 5 5g Fe203 53. (GSK-27) 00 1) EDA+DLEl'A 0.540.5 5 5 Ig Blenzoyladenine 54. (GSK-28 100 10 EDA 4i DETA 0.5 1 o.5 5 5 Ig BeiIla(e (GSK-29) 100 10 EDA+JDI'A 0.5-10.5 I'B-zol 1 5 56. (GSK-30) 100 10 EDA-t I)IA 0.5+t-0.5 5 5 2.25 g Merpan 57. (GSK-31) 100 10 EDA DDUTA 0.5-f0.5 5 5 2 g Slarci 58. 100 10 Ei)AiE'IA 1 ii 5 5 0.5 g tvg(N0 3 )2 59. 100 10 EDA+I) IEA 1+i 5 5 0.5 g Na 2

B

4 07 100 10 EDA+-DErA 1.1I 5 5 0.5 g FeS04 61. 100 10 EDA+DETA 1+1 5 5 0.5g Z S04 62. 100 10 FI)Aii)EIA 14.1 5 5 0.5 g Ca (NO 3 2 63. 100 10 EIA+ 1)EIA 1 t1 5 5 0.5 g MlIS0 4 100 10 ElDiI+TA 111 5 5 0.5 g (NI-1 4 6 K10 7 0 2 4 The compound Benedate referred to above is also known by its common name benomyl and its IUPAC name methyl 1 -(butylcarbamoyl)benzimidazol-2-ylcarbamate.

The compound Folpane referred to above is also known by its common name folpet and its IUPAC name N-(trichloromethylthio)phthalimide.

The compound Merpan referred to above is also known by its common name captan and its IUPAC name N-(trichloromethylthio)cyclohex-4-ene-1,2-dicarboximide.

The compound Nephorex referred to above is also known by its common name cyromazine and its IUPAC name N-cyclopropyl-1,3,5-triazine-2,4,6-triamine.

The compound Majic referred to above is also known by its common name paclobutrazol and its IUPAC name (2RS,3RS)-1 -(4-chlorophenyl)-4,4-dimethyl-2-(1 H-1,2,4-triazol-1 -yl)-pentan-3-ol.

Biological methods: Each cutting was put in a vessel with special earth and with 3 granules. the cuttings were put in green houses. The amount of roots and the length of the roots were measured.

The plants utilized included were Phelargonium: roses, melloloica, olives from different clutivars, eucalyptus of different kinds and many others. The biological tests were carried out with up to 7,000 cuttings for each plant. These tests consisted of various soft cuttings easy-to-root, semi-woody cuttings medium-to-root, difficult-to-root cuttings and grasses.

Select formulations were tested.

The biological results on several kinds of plants are summarized in tables 2-7.

<C

4^ IP:: t.'E WO 99/07654 PCT/IL98/00322 11 TABLE 2 BIOASSAY BASED ON MUNG-BEAN CUTTINGS TO TEST EFFECT OF ENCAPSULATED FERTILIZERS Treatment Average No. Average Root Length CM Roots 6 Days 10 days after treatment Control (H 2 0) 2.5 0.4 0.9 IBA 21.7 0.2 0.4 39.9 0.6 1.1 42.2 0.5 WO 99/07654 WO 9907654PCTIIL98/00322 TABLE 3 EFFECT OF ENCAPSULATED FERTI-LIZERS GSK10 ON CUTTINGS OF OLIVE CULTIVARS ROOTING OF Cultivar Percent of Average No. Root Average Root Rooting Length (cm) Control Manzanillo 26 2.3 7.6 Barnea 49 4.0 Nabali 31 3.5 6.3 Chin-dli 19 3.7 Maalot 22 1.6 5.9 T-8 (Conventional Treatment) Manzanillo 48 3.6 4.2 Barnea 73 4.8 3.4 Nabali 52 4.4 5.2 Chimlali 46 5.1 Maalot 54 3. 8 4.7 GSK- Manzanillo 52 5.3 8.8 Barnea 89 6.1 9.6 Nabali 61 5.8 7.2 Chirnlali 58 5.6 6.6 Maalot 76 4.5 7.9 WO 99/07654 PCT/IL98/00322 13 Table 4 EFFECT OF GSK-10 ON ROOTING OF VARIOUS PLANT SPECIES. THE TRAIL WAS DONE WITH 7000 CUTTINGS AT "GAT" COMMERCIAL NURSERY Plant name Picus Natasha Solanum blue Copea shrub Picus Thailand Hibicus Juniper espanicum Juniper galwcos Huniper Ramat Hnandiv Cypress lemon Bougainvillea Glabra (purple) Bougainvillea smooth Cestrum Rosa indica Ethrog yaman Pandorea Jasmin Solanum White Olive-K18 Olive-Nabali Miaforum Malloloika dwarfish Kles Tamun Tchaltsporum jasmine Cypress Tota Cypress cazoica rooting 71 82 94 82 78 93 94 0 98 89 98 84 36 0 0 0 alive with callus WO 99/07654 PCT/IL98/00322 14 Table EFFECT OF GSK-10 ON DEVELOPMENT OF ROOT SYSTEM OF CUTTINGS OF

EUCALYPTUS

Root system development ladder: Roots distributed in less than 25% of the pot medium Roots distributed in about 50% of the pot medium Roots distribution in morethan 75% of the pot medium Treatment Clone control T-8 Anulata Gillii Ficifolia ++4 Kruseana Popolnea ++4 WO 99/07654 PCT/IL98/00322 TABLE 6 EFFECT OF ENCAPSULATED FERTILIZERS ON SHOOT OLIVE ROOTED PLANTS DEVELOPMENT OF Treatment Average Shoot Elongation (cm) Days 60 days after treatment T-8 2.2 4.3 (Conventional treatment) Al 1.8 4.1

A

2 4.0 7.3 BI 3.6

C

1 2.7 WO 99/07654 PCT/IL98/00322 16 TABLE 7 EFFECT OF ENCAPSULATED FERTILIZERS GSK-10 ON VEGETATIVE AND REPRODUCTIVE DEVELOPMENT OF SOLANUM BLUE ROOTED PLANTS Treatment Transplanting date Average Root Average Number of height CM flowers/plants Conventional March 10 43 9 April 17 87 26 WO 99/07654 PCT/IL98/00322 17 The release rate was determined by the following method, one gram of the granules were placed in a dissolution system. Samples were taken from the vessels and the amount released was determined in the following way: the amount of the fertilizer by conductometeric method and the amount of the hormone by HPLC.

Very promising results concerning the rate of root formation, length of roots, survival of plants and ease of high mass plant production were clearly observed.

The formulations were found to be most effective in: accelerating root formation, increasing rooting percentage, improving the quality of root system, and stimulation of young plant (vegetative and reproductive) development in comparison to untreated control and IBA talc powder (the common substance used at present for rooting in all nurseries).

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative examples and that the present invention may be embodied in other specific forms without departing from the essential attributes thereof, and it is therefore desired that the present embodiments and examples be considered in all respects as illustrative and not restrictive, reference being made to the appended claims, rather than to the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims (17)

1. A controlled-release encapsulated fertilizer comprising a core containing at least one fertilizer and a polymeric coating containing at least one plant hormone encapsulating said fertilizer.

2. A controlled-release encapsulated fertilizer according to claim 1, wherein said coating contains at least one hormone selected from the group consisting of indole alkyl acid; indole acetic acid (IAA); indole propionic acid (IPA); indole butyric acid (IBA); 2,4 dichlorophenoxy acetic acid; 2,4 chlorophenoxy propionic acid; 2,4 dichlorophenoxyacetic acid propyl ester; and, naphthalene acetic acid.

3. A controlled-release encapsulated fertilizer according to claim 1 or 2, wherein said polymeric coating is formed by a polymer selected from the group consisting of polyurethane; polyurea; and, polyolefins.

4. A controlled-release encapsulated fertilizer according to any one of the Spreceding claims, further comprising a triazole incorporated therein. 0 20 5. A controlled-release encapsulated fertilizer according to claim 4, wherein said triazole is paclobutrazole.

6. A controlled-release encapsulated fertilizer according to any one of the preceding claims, further comprising a cytokinine incorporated therein.

7. A controlled-release encapsulated fertilizer according to claim 6, wherein said cytokinine is benzoyladenine.

8. A controlled-release encapsulated fertilizer according to any one of the preceding claims, further comprising a carbohydrate incorporated therein.

9. A controlled-release encapsulated fertilizer according to claim 8, wherein said carbohydrate is selected from the group consisting of glucose, sucrose and S<,,starch. -19- A controlled-release encapsulated fertilizer according to any one of the preceding claims, further comprising a fungicide incorporated therein.

11. A controlled-release encapsulated fertilizer according to claim 10, wherein said fungicide is selected from the group consisting of Benelate, folpane, merpan and propionazal.

12. A controlled-release encapsulated fertilizer according to any one of the preceding claims, further comprising an insecticide incorporated therein.

13. A controlled-release encapsulated fertilizer according to claim 12, wherein said insecticide is diazinone or nephorex.

14. A process for encapsulating a fertilizer comprising: a) coating a fertilizer with a mixture of a first monomer and a plant hormone; b) adding a mixture of a second monomer and an additional hormone; o and, S 20 c) heating said mixtures to induce the polymerization of said first and second monomers to form a polymeric coating incorporating said hormone and encapsulating said fertilizer.

15. A process for encapsulating a fertilizer according to claim 14, wherein said 25 coating contains at least one hormone selected from the group consisting of indole alkyl acid; indole acetic acid (IAA); indole propionic acid (IPA); indole butyric acid (IBA); 2,4 dichlorophenoxy acetic acid; 2,4 chlorophenoxy propionic acid; 2,4 dichlorophenoxyacetic acid propyl ester; and, naphthalene acetic acid.

16. A process for encapsulating a fertilizer according to claim 14, wherein said polymeric coating is formed by a polymer selected from the group consisting of polyurethane; polyurea; and, polyolefins. CW.fi:\nona\Sp.ccs\82390.doc

17. A process for encapsulating a fertilizer according to claim 14, wherein said coating contains at least one hormone selected from the group consisting of (indole alkyl acid; indole acetic acid (IAA); indole propionic acid (IPA); indole butyric acid (IBA); 2,4 dichlorophenoxy acetic acid; 2,4 chlorophenoxy propionic acid; 2,4 dichlorophenoxyacetic acid propyl ester; and, naphthalene acetic acid), and further optionally comprising at least one further component selected from the group consisting of a growth retardant, a cytokinine, a carbohydrate, a fungicide and a insecticide.

18. A controlled release fertilizer according to any one of claims 1 to 13 when produced by a process according to any one of claims 14 to 17.

19. A fertilizer according to claim 1 substantially as hereinbefore described with reference to any of the examples. A process according to claim 14 substantially as hereinbefore described with reference to any of the examples. BEN GURION UNIVERSITY OF THE NEGEV RESEARCH AND DEVELOPMENT AUTHORITY 20 DATED: 26 September, 2000 PHILLIPS ORMONDE FITZPATRICK :•0•Attorneys for: 2: BEN GURION UNIVERSITY OF THE NEGEV ooo 25 RESEARCH AND DEVELOPMENT AUTHORITY *oo S**