GB2155750A

GB2155750A - Phosphonic oil palm fruit bunch ripening and loosening method

Info

Publication number: GB2155750A
Application number: GB08407236A
Authority: GB
Inventors: Chin Ping Sang; Dr Ibrahim B Mamat; Abd Rahman B Abdullah
Original assignee: WILA CHEMICALS Sdn Bhd
Current assignee: WILA CHEMICALS Sdn Bhd
Priority date: 1984-03-20
Filing date: 1984-03-20
Publication date: 1985-10-02
Also published as: GB8407236D0

Abstract

Certain described phosphonic acid derivatives, particularly 2-chloroethyl phosphonic acid, applied either by painting on to the cut surface of the peduncle of the oil palm bunch soon after harvest or as a post harvest spray on the whole bunch, accelerate the rate of ripening of the individual oil palm (Elaeis guineensis) fruits. This treatment also enhances the loosening of the individual fruits while being processed. The phosphonic acid derivative is preferably in the form of an aqueous formulation, which may additionally comprise a penetrant in the case when it is sprayed on to the fruit bunch.

Description

SPECIFICATION Phosphonic Oil Palm Fruit Bunch Ripening and Loosening Method This invention relates to a method of inducing the ripening and loosening of oil palm fruit and to a composition for use in the method.

It is well known that the free fatty acid contents of palm oil extracted from the pericarp of the oil palm fruits is indicative of its quality. At the correct stage of ripeness, the free fatty acid content of the oil palm pericarp is at its lowest, and it increases very rapidly as this ripeness advances.

It has also been proved that under-ripe fruits of the oil palm have a low oil content. This oil content increases very rapidly as the fruits ripen, and is at its highest when the fruit is fully ripe. Thus it is important that the oil palm fruit bunches should be harvested at the correct stage of ripeness, in order to obtain a high oil content with a low free fatty acid content.

The general practice of harvesting the oil palm fruit is to cut the fruit bunch at the base of its peduncle when the fruit bunch indicates signs of ripening. As these indications are not easily identifiable in the field, a compromise method of assessing the stage of ripenness of the oil palm fruit bunch was accepted. This is based on the number of loose fruits found on the ground at the base of the palm. Although this method of assessment is the best under present conditions, it has shown that fruit bunches of varying degrees of ripeness are harvested within the same field at each harvesting round.

However this situation is further aggravated by the fact that oil palm growers carry out harvesting rounds at certain definite intervals of one to two weeks depending on the crop.

One other factor that needs to be mentioned here is that the oil palm fruits within the same bunch do not all ripen at the same time. Naturally the ripening process of the harvested oil palm fruit bunch takes between 5 to 7 days, beginning with fruits at the tip of the bunch. Thus within the same bunch, fruits of different stages of ripening are found.

Avery recent development in the oil palm industry is the release of the weevil Elaeidobius Kamerunicus, an efficient insect pollinator of the oil palm flowers. This has led to the production of bunches which are bigger and heavier and in which the fruits are more closely packed.

The introduction of E. Kamerunicus has been an important development in oil palm industry, although it has only taken place within a relatively short period. A number of advantages have been ascertained and sixty-three percent of the estates today are of the opinion that E. Kamerunicus has led to an increase of Fresh Fruit Bunches (FFB) production of both young and old oil palms and hence increases in palm oil yield at the mill.

Despite the advantages E. Kamerunicus offers to the industry, numerous disadvantages have also been identified. The major disadvantages are the problems that are encountered at the operational mills, where the processing of weevil-pollinated bunches leads to problems of sterilisation and stripping of the bunches.

(Refer: Palm Oil Research Institute of Malaysia, occasional paper lssn-0127-2209, March 1983).

The process of sterilization has become more difficult as steam can no longer penetrate fully into the bunches which are now more bulky and compact compared to pre-weevil days. This problem of inadequate steam penetration into the FFB (hence inadequate sterilisation) was reported by the majority of mills as indicated by 77.5% of the mills surveyed. The result is that not all the fruits are detached from the fruit-bunch during the sterilisation process. This problem is getting more pronounced, the oil extraction rate is reduced, and extra recycling time for sterilisation and stripping is required thereby increasing the milling costs.

It is an object of the invention to promote the ripening and loosening of oil palm fruits and to overcome the above disadvantages and problems due to the introduction of E. Kamerunicus as a natural oil palm pollinating agent.

According to the present invention, there is provided a method of inducing the ripening and loosening of oil palm fruits, wherein an oil palm fruit bunch is contacted with a phosphoric acid derivative of the formula

where R is a haloethyl or phosphono-ethyl radical, A is an oxygen or sulphur atom, and R1 and R2 are 1) each a chlorine atom, a hydroxy group or an -SH group, 2) each an ORS or-O-CH2R3 radical where R3 is an unsubstituted or substituted aryl radical or a heterocyclic radical, 3) each an -OR4 or-O-CH2R4 where each R4 is different and in a hydrogen atom, or an unsubstituted or substituted alkyl radical, an unsubstituted or substituted aryl radical, a heterocyclic radical, an alkene radical or an alkyne radical, with the proviso that when one R4 is an unsubstituted or substituted alkyl radical, an alkene radical or an alkyne radical, the other R4 is an unsubstituted or substituted aryl radical or a heterocyclic radical, 4) R1 and R2 together represent a

radical, where one of R5 and R6 is an oxygen atom and the other is an oxygen atom, a -CO-O- or -CONH- radical, and R7 is a benzene, substituted benzene, heterocyclic or substituted heterocyclic radical, or 5) one of R1 and R2 is -OR8 and the other is

where each R8 is a hydrogen atom, or unsubstituted or substituted alkyl radical, an unsubstituted or substituted aryl radical or a heterocyclic radical, and R is as defined above.

Phosphonic acid or "ethephon" as it is commonly called, releases ethylene in the plant (bunch) cells, when applied to the fresh cut fruit bunches. This desirability of an ethylene response or an ethylene-type response has been appreciated for many years. Indeed, ethylene has been used in gaseous form for the ripening of bananas, mangoes, pineapples and to stimulate flower initiation in many fruiting plants and other flowering plants.

The mechanism by which ethylene and other gases affect the growth cycle of plants is far from fully understood, but it is very clear that they do play a role. It will be seen that the phosphonic acid compounds and derivatives used to practise the present invention contain in their structures molecular configurations which are capable of breaking down into ethylene or like compounds, although there is no intention to limit the present invention to this theory or any other theory.

The use of certain other phosphonate compounds in the agricultural art is known for herbicidal purposes as set forth in some U.S. Patents. However, the compounds disclosed in the aforesaid patents do not produce the growth regulating responses for ethylene-type response of the present invention.

Referring to the general formula defined above, the preferred values for substituent R are haloethyl, for example, 2-bromoethyl and 2-iodoethyl.

Preferred half-esters of the phosphonic acid moiety include the 2-chloroethyl mono-ester and o-hydroxyphenyl mono-ester. Preferred diesters include the diphenyl and the bis (2-oxo-1-pyrrolidinylmethyl) esters and as mixed esters, the 2-hydroxyphenyl ester with an alkyl or alkenyl or aryl radical for example, ethyl, isopropyl, propynyl, butyl, octyl, hexadecyl or phenyl radicals. Aryl radicals are preferably monocyclic, but bi or polycyclic aryl radicals may be used provided they contain a group to render them soluble.

The term "alkyl" as used herein is intended to include the analogous compounds which have the same growth promotion properties and includes for example cycloalkyl radicals, such as cyclohexyl. Preferred alkyl radicals are those having up to 18 carbon atoms because above this value the derivatives are less soluble.

Preferred cyclic esters include those formed with pyrocatechol or mono- or polyhalopyrocatechol derivatives, for example, 4-chloropyrocatechol ortetrachloropyrocatechol, and with salicyclic acid, salicyl alcohol and 2,3- pyridinediol. Other preferred derivatives include the acid chlorides.

The derivatives which may be used in the present method include the functional derivatives of the foregoing acids including the acid chlorides, am ides and cyclic esters, particularly certain amides of 2-chloroethylphosphonic acid.

The phosphonic acid derivatives employed in the present method should normally be compounds known to be readily hydrolyzable, in the laboratory or on the plant fruit bunches under treatment.

The ability of a phosphonic acid derivative to be used in the practice of the present method can initially be determined in actual field planting trials, to determine its power and effectiveness.

The phosphonic acid derivative is preferably in the form of an aqueous formulation comprising the derivative and may be painted on the cut surface of the peduncle of the oil palm fruit bunch soon after harvest or may be sprayed into the fruit bunches. In the latter case, the formulation preferably additionally comprises a penetrant to assist the sprayed liquid and contact all the fruits in the bunch.

The invention will now be illustrated by the following Examples of treatments carried out on newly harvested fresh fruit bunches of oil palm fruit using 2-chloroethyl phosphonic acid.

Fourformulationscontaining 15%, 10% 5% and 40% by weight respectively of 2-chloroethyl phosphonic acid in water were prepared, and freshly cut ends of newly harvested fresh fruit bunches were painted over with the formulations in respective treatments (treatments 1 to 4).

Four other treatments consisted of spraying newly harvested bunches with a 10% solution of 2-chloroethyl phosphonic acid in water additionally comprising a penetrant, 4800 ppm and 9600 ppm of 2-chloroethyl phosphonic acid in water respectively, and a control. (Treatments 5 to 8).

All the treatments were carried out immediately after the oil palm fruit bunches were cut down (harvested) from their trees. Each application by the method of painting on the fresh cuts was made at an average rate of 3.5 ml per bunch cuts. Meanwhile, by the method of spraying, an average of 1 litre mixture was used per bunch.

Observations were made and recorded at 0 hours, 24 hours and 48 hour intervals.

The result of the experiments are shown in the following Tables A, B, C and D(i) and (ii).

As shown in Table D(ii), treatment No. 7 where bunches were sprayed with 2-chloroethyl phosphonic acid at 9600 ppm in water, gave very encouraging results of 654.2% ripening over control (treatment 8) after 48 hours.

Even in treatments 2 and 3 where the lowest rates were applied, the response to treatment was encouraging at 212.1% and 156.1% respectively over control.

As shown in Table D(i), treatment No.7 which was carried out with the highest application rate, the percentage of loose fruits obtained over control was 1189.7%,48 hours after treatment. While treatments Nos. 2 and 3 treated at lower application rates showed 151.6% and 103.8% increase in loose fruits over control.

It can be seen from the foregoing that the present invention provides an extremely satisfactory method of inducing or hastening ripening as well as loosening of oil palm fruits from their bunches.

TABLE A Experiment No. 1

After Treatment Harvested Date : 2/2/83 Treatment Date : 2/2/83 Pretreatment-0 Hours 24 Hours 48 Hours Average Weight of No. of No. of No. of Total No.

No. of F.F.B. Loose Average Loose Average Loose* Average of Loose Average Treatment Bunches (Kg) Fruits % Ripen Fruits % Ripen Fruits % Ripen Frults % Ripen 1. 15% Ethephon 10 16.40 0 0 126 12.0 128 20.0 254 20.0 2. 10% Ethephon 10 12.50 0 0 86 10.0 86 15.0 172 15.0 3. 5% Ethephon 10 17.00 0 0 70 8.0 55 10.0 125 10.0 4. 40% Ethephon 10 15.12 0 0 646 15.0 448 30.0 1,094 30.0 5. 10% Ethephon 10 16.12 0 0 266 8.0 140 20.0 406 20.0 plus Penetrant 6. 4800 ppm 10 18.38 0 0 540 15.0 404 35.0 944 35.0 7. 9600 ppm 10 16.06 0 0 1004 30.0 600 80.0 1,604 60.0 8. Control 10 14.72 0 0 40 0 55 5.0 95 5.0 No. of loose fruits counted at 0 hours are based on fruits that dropped onto the ground at time of harvest.

* Additional no. of loose fruits 48 hours after treatment.

TABLE B Experiment No. 2

After Treatment Harvested Date : 8/2/83 Treatment Date : 8/2/83 Pretreatment-0 Hours 24 Hours 48 Hours Average Weight of No. of No. of No. of Total No.

No. of F.F.B. Loose Average Loose Average Loose* Average of Loose Average Treatment Bunches (Kg) Fruits % Ripen Fruits % Ripen Fruits % Ripen Frults % Ripen 1. 15% Ethephon 10 17.10 0 3.0 244 25.0 220 40.0 464 40.0 2. 10% Ethephon 10 19.18 0 2.4 168 15.0 172 28.0 340 28.0 3. 5% Ethephon 10 20.30 0 2.0 110 10.0 97 20.0 207 20.0 4. 40% Ethephon 10 19.86 0 2.0 806 28.0 588 45.0 1,194 45.0 5. 10% Ethephon 10 21.02 0 5.4 710 35.0 700 55.0 1,410 55.0 plus Penetrant 6. 4800 ppm 10 14.64 0 3.4 1126 37.0 1053 60.0 2,179 60.0 7. 9600 ppm 10 14.80 0 2.4 1268 56.0 1109 70.0 2,377 70.0 8. Control 10 18.26 0 3.6 124 5.00 103 12.0 227 12.0 No. of loose fruits counted at 0 hours are based on fruits that dropped on the ground at time of harvest.

*Additional No. of loose fruits 48 hours after treatment.

TABLE C Experiment No. 3

After Treatment Harvested Date : 15/3/83 Treatment Date : 15/3/83 Pretreatment-0 Hours 24 Hours 48 Hours Average Weight of No. of No. of No. of Total No.

No. of F.F.B. Loose Average Loose Average Loose* Average of Loose Average Treatment Bunches (Kg) Fruits % Ripen Fruits % Ripen Fruits % Ripen Frults % Ripen 1. 15% Ethephon 10 15.0 0 5.0 280 20.0 257 35.0 537 35.0 2. 10% Ethephon 10 13.40 0 3.0 173 15.0 151 25.0 324 25.0 3. 5% Ethephon 10 15.50 0 5.0 129 15.0 113 20.0 242 20.0 4. 40% Ethephon 10 14.60 0 2.0 599 25.0 536 45.0 1136 45.0 5. 10% Ethephon 10 16.30 0 5.0 737 40.0 612 60.0 1349 60.0 plus Penetrant 6. 4800 ppm 10 15.70 0 3.0 1115 35.0 987 50.0 2102 50.0 7. 9600 ppm 10 17.01 0 3.0 1370 50.0 1217 80.0 2587 80.0 8. Control 10 16.80 0 5.0 102 10.0 129 15.0 231 15.0 No. of loose fruits counted at 0 hours are based on fruits that dropped on the ground at time of harvest.

*Additional No. of loose fruits 48 hours after treatment.

TABLE D Data Summary (i) No. of Loose Fruits 048 Hours 10 Bunches/Treatment

Treatment Nos.

1 2 3 4 5 6 7 8 Experiment 1 254 172 125 1094 406 944 1604 95 Treatment 3/10/83 Experiment 2 464 340 207 1194 1410 2179 2377 227 Treatment 10/10/83 Experiment 3 537 324 242 1136 1349 2102 2587 231 Treatment 25/10/83 Total 1255 836 574 3424 3165 5225 6568 553 Average 418 279 191 1141 1055 1742 2189 184 Response 227.2 151.6 103.8 620.0 573.4 946.7 1 1189.7 100 over control % TABLE D (continued) (ii) Percentage Ripen 0-48 Hours 10 Bunches/Treatment

Treatment Nos.

1 2 3 4 5 6 7 8 Experiment 1 20.0 15.0 10.0 30.0 20.0 35.0 60.0 5.0 Treatment 3/10/83 Experiment 2 40.0 28.0 20.0 45.0 55.0 60.0 70.0 12.0 Treatment 3/10/83 Experiment 3 35.0 25.0 20.0 45.0 60.0 50.0 80.0 15.0 Treatment 25/10/83 Total 95.0 68.0 50.0 120.0 135.0 145.0 210.0 32.0 Average 31.7 22.7 16.7 40.0 45.0 48.3 70.0 10.7 Response 296.3 212.1 156.1 373.8 420.6 451.4 654.2 100.0 Over Control %

Claims

1. A method of inducing the ripening and loosening of oil palm fruits, wherein an oil palm fruit bunch is contacted with a phosphonic acid derivative of the formula R' # R-P # # A R where R is a haloethyl or phosphono-ethyl radical, A is an oxygen or sulphur atom, and R1 and R2are 1) each a chlorine atom, a hydroxy group or an -SH group, 2) each an -OR3 orOCH2R3 radical where R3 is an unsubstituted or substituted aryl radical or a heterocyclic radical, 3) each an -OR4 or-O-CH2R4 where each R4 is different and in an hydrogen atom, or an unsubstituted or substituted alkyl radical, an unsubstituted or substituted aryl radical, a heterocyclic radical, an alkene radical or an alkyne radical, with the proviso that when one R4 is an unsubstituted or substituted alkyl radical, an alkene radical or an alkyne radical, the other R4 is an unsubstituted or substituted aryl radical or a heterocyclic radical.

4) R' and R2 together represent a

radical where one of R5 and R6 is an oxygen atom and the other is an oxygen atom, a -CO-O- or -CON H- radical, and R7 is a benzene, substituted benzene, heterocyclic or substituted heterocyclic radical, or 5) one of R1 and R2 is-OR8 and the other is

2. A method as claimed in Claim 1, wherein the fruit bunch is contacted with an aqueous formulation comprising the phosphonic acid derivative.

3. A method as claimed in Claim 2, wherein the formulation additionally comprises a penetrant.

4. A method as claimed in any one of Claims 1 to 3, wherein the freshly cut ends of newly harvested fresh fruit bunches are contacted with said phosphonic acid derivative.

5. A method as claimed in Claim 2 or 3 wherein the fruit bunches are sprayed with the formulation.

6. A method as claimed in Claim 5, wherein the formulation comprises 4800 to 9600 ppm of the phosphonic acid derivative and is sprayed at the rate of approximately 1 litre per bunch.

7. A method as claimed in any one of Claims 1 to 6, wherein the phosphonic acid derivative is 2-chloroethyl phosphonic acid.

8. A method of inducing ripening and loosening of oil palm fruits substantially as hereinbefore described with reference to any one of the foregoing treatments 1 to 7.

9. The use of a phosphonic acid derivative of the formula defined in Claim 1 to induce the ripening and loosening of oil palm fruits.

10. The use of 2-chloroethyl phosphonic acid to induce the ripening and loosening of oil palm fruits.