GB1590625A

GB1590625A - Agricultural and horticultural processes

Info

Publication number: GB1590625A
Application number: GB2914476A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-07-06
Filing date: 1977-07-06
Publication date: 1981-06-03

Description

(54) AGRICULTURAL AND HORTICULTURAL PROCESSES (71) We, GRAHAM GEORGE THOMAS of Longacre, Selling, Nr.

Faversham, Kent and GERALD KILGOUR GOLDWIN of "Milland", Stone Hill, Sellindge, Kent, England, both British citizens, do hereby declare the invention for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a method of treating hop plants to augment the yield of hop cones therefrom.

According to the present invention, there is provided a method of augmenting the yield of hop cones from hop plants (Humulus lupulus L.), the method comprising applying to a hop plant which was flowered, an auxin, a gibberellin and, optionally, a substituted urea of the formula R'NHCONHR2 wherein R1 is a hydrogen atom, a substituted or unsubstituted hydrocarbyl group or a substituted or unsubstituted heterocyclic group and R2 is a substituted or unsubstituted phenyl group the total amount of said auxin, gibberellin and substituted urea (if used) being sufficient to augment the yield of hop cones.

The auxin, gibberellin and substituted area (when used) are preferably applied simultaneously.

Preferably the application is effected at the late burr stage. Application before the late burr stage tends to adversely affect the alpha acid content of the hop cones.

Suitably, the application is effected when the bracts and bracteoles commence to enlarge.

One or more than one application may be made and where more than one application is made, the initial application is preferably at the late burr stage.

Auxins and gibberellins are plant growth regulators of which numerous members are known and which promote cell enlargement.

More specifically, the auxins of which a very large number are used commercially, for example, as herbicides, may be characterised by the wheat coleoptile test or by the pea hypocotyl test. A large number of synthetic auxins mimic the physiological activity of the naturally occurring auxin, indolylacetic acid, and these synthetic compounds are advantageously used in the method of the invention.

Examples of auxins useful in the present invention are naphthyl derivatives, for example l-naphthylacetic acid and 2-naphthoxyacetic acid. Others are phenoxyalkanoic acids, including phenoxyacetic acids, for example 4 - chloro 2 - methylphenoxyacetic acid (MCPA), 2,4 - dichlorophenoxyacetic acid (2,4D) and 2,4,5 - trichlorophenoxyacetic acid (2,4,5-T); phenoxypropionic acids, for example 2 - (4 - chloro - 2 - methylphenoxy) propionic acid (CMPP or mecoprop) and 2- (2,4 dichlorophenoxy) propionic acid (2,4DP or dichlorprop); and phenoxybutyric acids, for example 4 - (2,4 - dichlorophenoxy) butyric acid (2,4 DB) and 4 - (4 - chloro - 2 - methylphenoxy) butyric acid (MCPB). A further class of auxins are the substituted benzoic acids, such as 2,4,5 - trichlorobenzoic acid (TBA); 3,5 - dichloro - 2 - methoxybenzoic acid (dicamba); 2,3,5 trichloro 6 - methoxybenzoic acid (tricamba); and 3 - amino - 2,5 - dichlorobenzoic acid (amiben). All the above acids are active in the form of their salts and esters, for example their sodium, potassium, ammonium, dimethylamine and ethanolamine salts, and their methyl, ethyl, propyl, and butyl esters. It is in the form of such salts and esters that they are generally used, and are preferably used in carrying out the present invention.

Gibberellins are a group of plant growth regulators originally derived commercially from cultures of the fungus Gibberellafuiikori. A description of these substances, the majority of which contain the gibbane ring is given by J. F. Grove in "The Gibberellins", Quarterly Reviews, 1961, 15, 56-71 published by the Chemical Society (Lond). The gibberellins include, for example gibberellin A3, also known as gibberellic acid, which is disclosed in United Kingdom patent Specification No.

783,611 and gibberellin A4. A further example, as disclosed by United Kingdom Patent Specification No. 914,893, is gibberellin A7. The patent specifications referred to above also disclose the preparation of ammonium, alkali metal and alkaline earth metal salts of gibberellins A3 and A7. Gibberellin A7 is obtained commercially as a mixture with an equal proportion of gibberellin A4, in which form it is used for plant growth regulating purposes. The gibberellins preferred for use in the method of the invention are gibberellins A3, A4 and A7.

As described above the substituted ureas used in the preferred method of treatment according to the present invention have the formula R1NHCONHR2 wherein R1 is a hydrogen atom, a substituted or unsubstituted hydrocarbyl group or a substituted or unsubstituted heterocyclic group and R2 is a substituted or unsubstituted phenyl group. The hydracarbyl groups represented by R1 may be aliphatic or aromatic, but are preferably aryl groups.

Suitable aliphatic groups include alkyl groups, both straight and branched having 1 to 12 carbon atoms, such as, for example, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, t-butyl, amyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl and dodecyl; alkenyl and alkaryl groups having 1 to 12 carbon atoms; and substituted or unsubstituted cycloalkyl groups such as, for example, cyclohexyl. The preferred aryl group is phenyl, but 1- or 2-naphthyl may also be used. Examples of suitable heterocyclic groups included pyridyl, pyrrolyl, quinolyl, indolyl, morpholyl and furyl. The hydrocarbyl and heterocyclic groups represented by R1 and the phenyl groups represented by R2 are optionally substituted with one or more of a wide variety of substituents, including in particular alkyl, alkoxy, haloalkyl, carboxy, carboxyalkyl, cyano, amino and nitro groups, as well as any of the halogens (F, Cl, Br and I). Examples of useful compounds include the following.

Compound R1 R2 No.

C6H5 C6H5 2 C6H5 p-f.C6H4 3 H p-Br.C6H4 4 4-pyridyl C6115 5 C6H5 NO2-4CH3 . C0H3 6 H 3,4Cl2.C8H3 7 CH3 C6H5 8 m-CH3.C6H4 m-F.C6H4 We particularly prefer to use N,N' - diphenylurea in the present invention because of its combination of activity, ease of manufacture and apparently favourable toxicological and environmental properties.

The substituted ureas used in our invention are known chemical compounds (with few exceptions) and may be made by a variety of well-known synthetic methods. These include, for example, hydrolysis of isocyanates; and reaction of isocyanates with amines.

For simultaneous application, the auxin, gibberellin and substituted urea (where used) may be formulated into a composition which may be solid or liquid.

Such compositions may be produced in forms which are ready for use or which are concentrated and require dilution before use. Preferably the compositions also comprise a surface-active agent to assist in spreading the compositions over the surface of the hop plants to which they are applied.

The solid compositions may, for example, be in the form of a powder, in which the active ingredients are mixed with a powdered solid diluent. Suitable solid diluents include for example, Fuller's earth, powered kaolin, gypsum, chalk and kieselguhr. Such solid compositions may be applied as foliar dusts, or diluted with water and applied by spraying.

Another form of solid composition comprises the active ingredients in finely divided form together with a disintegrating agent, e.g. a mixture of citric acid and an alkali metal bicarbonate. Such a composition may be moulded into tablets, which when added to water disintegrate rapidly to form sprayable suspensions.

The liquid compositions may comprise solutions or dispersions of the active ingredients in water optionally containing a surface-active agent, or may comprise solutions or dispersions of the active ingredients in an organic diluent, which may optionally contain a surface-active agent. Angther form of liquid composition comprises a solution of the active ingredients in a water-immiscible organic solvent which is dispersed as droplets in water.

Examples of surface-active agents which may be used in the compositions of the invention include the products of condensation of ethylene oxide with the following substances: alkyl substituted phenols such as octyl phenol and nonylphenol; sorbitan monolaurate; oleyl alcohol; and propylene oxide polymer.

Other satisfactory surface-active agents include calcium dodecylbenzenesulphonate, and calcium, sodium, and ammonium lignosulphonates.

In one form of concentrated composition which may be diluted to form a composition suitable for application to hop plants in accordance with the method of the invention the active ingredients are finely divided and are dispersed in water in the presence of a surface-active agent and a suspending agent. Preferred suspending agents are those which impart thixotropic properties to and increase the viscosity of the concentrate. Examples of preferred suspending agents include hydrated colloidal mineral silicates, such as montmorillonite, beidellite, nontronite, hextorite, saponite, and saucorite. Bentonite is especially preferred. Other suspending agents include cellulose derivatives and polyvinyl alcohol.

Only very small amounts of auxin and gibberellin are required to achieve augmented yields of hop cones; thus, sufficient quantities may be applied by spraying plants overall to run-off with a liquid composition containing, preferably, 0.5 to 50, more preferably 1 to 10 ppm of gibberellin arid 0.05 to 10, more preferably 0.1 to 5 ppm of auxin. Where a substituted urea is used, the liquid composition preferably contains 0 to 500 ppm, more preferably 0 to 50 ppm of substituted urea.

Treatment of the hop plant in accordance with the invention causes enlargement of the bracts and bracteoles of the cones and thus augments the yield of hop cones from a plant.

This invention is illustrated by the following Examples.

EXAMPLE 1 This Example illustrates the treatment of non-pollinated hop plants of the variety "Northern Brewer" in accordance with the process of this invention in a commercial hop garden in Kent in 1975.

The hop garden was divided into ten identical areas. On 20th August 1975, five of the areas were treated with an aqueous composition containing as active ingredients 5 ppm of gibberellic acid, 3 ppm of N,N'-diphenylurea and 0.5 ppm of 2-naphthoxyacetic acid. This composition was sprayed on the plants at the rate of 200 gallons/acre using a Drake and Fletcher Victair Senior sprayer.

The remaining five areas were not treated.

The hop cones from all ten areas were harvested on 5th and 9th September 1975 using a commercial picking machine and the harvested cones were dried to standard commercial dryness. The dry yield, mean cone weight, mean alpha acid content of the cones and overall yield of alpha acid were calculated for each of the ten areas and the mean values obtained for the five treated areas and five untreated areas are set out below.

Treated Areas Untreated Areas Mean dry yield of cones (Zentners/hectare) 30.1 * 26.8 Mean cone weight (g) 0.1694 0.1594 Mean alpha-acid content of the cones (% by weight) 9.2 9.1 Overall yield of alpha-acid (Kg/hectare) 137** 122 *value significantly different from value for Untreated Areas at 50/, level.

**value significantly different from value for Untreated Areas at 1% level.

EXAMPLE 2 This Example illustrates the treatment of hop plants of the variety "Wye Target" in accordance with the invention in a hop garden at Waterinbury, Kent in 1976. The hop plants were grown seeded.

The treatment was carried out at the late "burr" stage of cone development in a manner similar to that described in Example 1 using a solution containing gibberellic acid (5 ppm), N,N' - diphenylurea (3 ppm) and 2 - naphthoxyacetic acid (1 ppm). The solution was sprayed at a rate of 200 gals/acre.

The results are set forth below: Treated Areas Untreated Areas Kiln dry weight/string of cones (mean of two replicates) 0.6731b 0.5561b Increase in dry weight yield 21% Total alpha acid/string (mean of two replicates) 0.07161b 0.05861b Increase in yield of alpha acid 22 /" EXAMPLE 3 This Example, which was carried out in the manner described in Example 2 illustrates the treatment of hop plants of the variety "Wye Challenger" in a hop garden at Rosemaunde Experimental Horticultural farm in 1976. The hop plants were grown seedless.

The results are set forth below: Treated Areas Untreated Areas Dry yield of cones (Zentners/hectare-mean of six replicates) 34.9 33.68 Standard Error of difference between means 0.48 Increase in dry yield 3.6 /" EXAMPLE 4 This Example, which was carried out in the manner described in Example 2 illustrated the treatment of hop plants of the variety "Northern Brewer" in a hop garden at Wye, Kent in 1976. The hop plants were grown seedless.

The results are set forth below: Treated Areas Untreated Areas Dry weight of cones/string (mean of twelve replicates) 0.3481b 0.3391b Increase in dry weight yield 2.7% EXAMPLE 5 This Example, which was carried out in the manner described in Example 2, illustrates the treatment of hop plants of the variety Northern Brewer in a hop garden at Stokes Bomford in 1976. The hop plants were grown seedless.

The results are set forth below: Treated Areas Untreated Areas Dry weight of cones (mean of two replicates) I 6.00centals/acre I 3.75centals/acre Increase in dry weight yield 16% WHAT WE CLAIM IS: 1. A method of augmenting the yield of hop cones from hop plants which method comprises applying an auxin and a gibberellin to a hop plant which has flowered, the total amount of auxin and gibberellin being sufficient to augment the yield of hop cones.

2. A method according to claim 1 in which the auxin is 2 - naphthoxyacetic acid or a salt or ester thereof.

3. A method according to claim 2 in which the auxin is 1 - naphthylacetic acid or a salt or ester thereof.

4. A method according to claim 1 in which the auxin is a phenoxyalkanoic acid of a salt or ester thereof.

5. A method according to claim 4 in which the auxin is selected from 4 chloro - 2 - methylphenoxyacetic acid, 2,4 - dichorophenoxyacetic acid, 2,4,5 trichlorophenoxyacetic acid, 2 - (4 - chloro - 2 - methylphenoxy) - propionic acid, 2 - (2,4 - dichlorophenoxy) - propionic acid, 4 - (4 - chloro - 2 - methylphenoxy) - butyric acid and salts and esters thereof.

6. A method according to claim 1 in which the auxin is a substituted benzoic acid or a salt or ester thereof.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. The treatment was carried out at the late "burr" stage of cone development in a manner similar to that described in Example 1 using a solution containing gibberellic acid (5 ppm), N,N' - diphenylurea (3 ppm) and 2 - naphthoxyacetic acid (1 ppm). The solution was sprayed at a rate of 200 gals/acre. The results are set forth below: Treated Areas Untreated Areas Kiln dry weight/string of cones (mean of two replicates) 0.6731b 0.5561b Increase in dry weight yield 21% Total alpha acid/string (mean of two replicates) 0.07161b 0.05861b Increase in yield of alpha acid 22 /" EXAMPLE 3 This Example, which was carried out in the manner described in Example 2 illustrates the treatment of hop plants of the variety "Wye Challenger" in a hop garden at Rosemaunde Experimental Horticultural farm in 1976. The hop plants were grown seedless. The results are set forth below: Treated Areas Untreated Areas Dry yield of cones (Zentners/hectare-mean of six replicates) 34.9 33.68 Standard Error of difference between means 0.48 Increase in dry yield 3.6 /" EXAMPLE 4 This Example, which was carried out in the manner described in Example 2 illustrated the treatment of hop plants of the variety "Northern Brewer" in a hop garden at Wye, Kent in 1976. The hop plants were grown seedless. The results are set forth below: Treated Areas Untreated Areas Dry weight of cones/string (mean of twelve replicates) 0.3481b 0.3391b Increase in dry weight yield 2.7% EXAMPLE 5 This Example, which was carried out in the manner described in Example 2, illustrates the treatment of hop plants of the variety Northern Brewer in a hop garden at Stokes Bomford in 1976. The hop plants were grown seedless. The results are set forth below: Treated Areas Untreated Areas Dry weight of cones (mean of two replicates) I 6.00centals/acre I 3.75centals/acre Increase in dry weight yield 16% WHAT WE CLAIM IS:

1. A method of augmenting the yield of hop cones from hop plants which method comprises applying an auxin and a gibberellin to a hop plant which has flowered, the total amount of auxin and gibberellin being sufficient to augment the yield of hop cones.

7. A method according to claim 6 in which the auxin is selected from 2,4,5

trichlorobenzoic acid, 3,5 - dichloro - 2 - methoxybenzoic acid, 2,3,5 - trichloro 6 - methoxybenzoic acid, 3 - amino - 2,5 - dichlorobenzoic acid and salts and esters thereof.

8. A method according to any preceding claim in which the gibberellin is selected from gibberellin A3, gibberellin A4 and gibberellin A,.

9. A method according to any preceding claim in which the auxin and the gibberellin are applied simultaneously.

10. A method according to any preceding claim in which the auxin and gibberellin are applied in the form of a liquid composition containing from 0.5 to 50 ppm of gibberellin and from 0.05 to 10 ppm of auxin.

11. A method according to claim 10 in which the composition contains from 1 to 10 ppm of gibberellin and from 0.1 to 5 ppm of auxin.

12. A method according to any preceding claim in which a substituted urea of the formula RtNHCONHR2, wherein R1 is a hydrogen atom, a substituted or unsubstituted hydrocarbyl group, or a substituted or unsubstituted heterocylic group and R2 is a substituted or unsubstituted phenyl group is applied to the hop plant.

13. A method according to claim 12 in which R1 represents a substituted or unsubstituted alkyl, alkenyl or alkaryl group having from I to 12 carbon atoms or a substituted or unsubstituted cycloalkyl group.

14. A method according to claim 12 in which R' represents a substituted or unsubstituted pyridyl, pyrrolyl, quinolyl, indolyl, morpholyl or furyl group.

15. A method according to claim 12 in which R1 represents a substituted or unsubstituted aryl group.

16. A method according to any one of claims 12 to 15 in which the hydrocarbyl or heterocyclic groups represented by R1 and/or the phenyl group represented by R2 are substituted by one or more substituents selected from alkyl, alkoxy, haloalkyl, carboxy, carboxyalkyl, cyano, amino and nitro groups and halogen atoms.

17. A method according to claim 12 in which the substituted urea is N,N' diphenyl urea.

18. A method according to any one of claims 12 to 17 in which a liquid composition containing from 0 to 500 ppm of said substituted urea is applied to the plants.

19. A method according to claim 18 in which a liquid composition containing from 0 to 50 ppm of said substituted urea is applied to the plants.

20. A method according to any of claims 12-19 in which the auxin, the gibberellin and the substituted urea are applied simultaneously to the plants.

21. A method of treating hop plants according to claim 1 and substantially as hereinbefore described.

22. Any method of treating hop plants which is substantially as described herein as a specific embodiment of the method defined in claim 1.

23. Hop cones whenever obtained from plants treated by a method according to any preceding claim.

Reference has been directed in pursuance of section 9, subsection (1) of the Patents Act 1949, to patent No. 1209743.