GB2156827A

GB2156827A - Apparatus for and method of protecting rubber trees from rain

Info

Publication number: GB2156827A
Application number: GB08407748A
Authority: GB
Inventors: Brian John Wood; Chai Yee Ho; Lian Tiong Gan; Oe Kheng Chew
Original assignee: Agri Bio Corp
Current assignee: Agri Bio Corp
Priority date: 1984-03-26
Filing date: 1984-03-26
Publication date: 1985-10-16
Also published as: GB2156827B; MY100136A; GB8407748D0

Abstract

A hood device (20) of a material such as asphalt roofing felt is of substantially crescent shape. The device is secured to a tree by laying the hood device (20) against the tree surface with the inner curved edge portion lowermost and the line joining the centres of the inner and outer edge portions lying parallel to the longitudinal axis of the tree. A layer of adhesive is applied to the lower edge portion of the hood device (20) and an area of the trunk lying adjacent the lower edge portion. The hood device is turned round and the adhesive carrying edge portion of the hood device (20) is adhered to the adhesive applied to the tree. The material of the hood device (20) is folded over. <IMAGE>

Description

SPECIFICATION Apparatus for and method of protecting rubber trees from rain The invention relates to apparatus for and methods of protecting rubber trees from rain.

More particularly but not exclusively, the invention relates to protecting Hevea rubber trees.

Exploitation of latex from Hevea rubber trees is very susceptible to rain interference.

Heavy rain before or during tapping results in trees being too wet to be tapped or it is not practical to go on tapping. Furthermore, tapping must be delayed until trees are dry, and rain during the night will cause water from the tree canopy to continue to run down the trunk, prolonging the time taken for the trees to dry. Also, rain falling during tapping will result in crop losses, and rain immediately after tapping may also cause the loss of the late drip.

As an illustration of the problem, the annual rain days in Malaysia ranges from 100-200 days. The magnitude of rain interference varies from location to location, however may average to about 15-20 percent. The estimated crop loss due to rain interference can be in the range of 100-300 kilogram dry rubber per hectare per year. The greatest problem encountered by rubber planters have been on how to minimise panel wetting.

Various attempts had been made in this area to minimise the problem, these were (i) the 'Conventional Method' by fixing a polythene sheet above and parallel to the tapping groove so as to partially cover the tapping panel. This method is not practical and the method resulted in a high humidity at the panel which induced panel disease development.

(ii) the 'Channel Method' eg using jute hessian, polythene tube, expanded polystyrene, aluminium foil, and other material such as rubber tubing and rubber gutter.

Although these two methods had been tested using various materials except bitumen based material, the use of rainguard has not been accepted as a standard practice in the rubber plantations.

According to a first aspect of the invention, there is provided a hood device of sheet material for protecting a rubber tree tapping groove, which hood device has a substantially crescent shape defined by an inner curved edge portion adapted to be secured around at least a part of a tree trunk and an outer curved edge portion, in use the hood device providing a surface extending outwardly and downwardly from the inner curved edge portion secured to a tree.

The substantially crescent shape may be defined by the edge portions being or comprising- semicircles, semi- elipses, hyperbolic, parabolic or cycloidal.

The hood device may be of polymeric material, such as polyethylene, or bitumen based material, or metallic sheeting such as tin or aluminium, or indeed a flexible plastics material.

The invention further provides a method of securing a hood device according to the invention to a tree which method comprises the steps of laying the hood device against the tree surface with the inner curved edge portion lowermost and a line joining the centres of the inner and outer edge portions lying parallel to the longitudinal axis of the tree, applying a layer of adhesive, preferably a solvent based contact adhesive, to the lower edge portion of the hood device and an area of the trunk lying adjacent the lower edge portion, turning the hood device round and adhering the adhesive carrying edge portion of the hood device to the adhesive applied to the tree and progressively folding over the material of the hood device to form a hood.

According to a further aspect of the invention there is provided a rainguard of bitumen based material suitable for use on a rubber tree to shield a tapping groove on the tree from rain. The bitumen based material may be asphalt roofing felt.

According to a yet further aspect of the invention there is provided a method of securing a rainguard to a rubber tree comprising the step of adhering the rainguard to the tree trunk with a volatile solvent based contact adhesive.

The adhesive is preferably applied both to the rainguard and to the trunk, and preferably left to dry for a predetermined period, for example thirty minutes, before application of the rainguard to the trunk.

According to a still further aspect of the invention there is provided a method of securing a rainguard to a rubber tree comprising the steps of securing the rainguard to the tree and applying a sealant compound to seal the joint between the rainguard and the tree.

The sealant compound may be bitumen tar, petroleum based contact adhesive, grease or rubberised clay.

By way of example, embodiments of a hood device for protecting a rubber tree tapping groove and methods of securing such devices to a rubber tree and thereafter sealing them according to the invention will now be described with reference to the accompanying drawings, in which: Figures 1(a), 1(b) and 1(c) illustrate different shapes of hood device according to the invention; Figures 2(a), 2(b), 2(c), 2(d) and 2(e) show a hood device secured to a rubber tree, the views being respectively a sectional view, a rear elevation, a side elevation, a front elevation and a side elevation from the other side; and Figures 3(a), 3(b), 3(c) and 3(d) illustrate the successive steps involved in securing a hood device according to the invention to a tree trunk.

As shown in Fig. 1, a hood device according to the invention may be in various different shapes. The hood device shape is formed by two similar and spaced apart edge portions of a circular function such as a hyperbola, parabola, ellipse, circle or cycloid. The similar edge portions 10(a), 10(b) and 10(c) in Figs.

1(a), 1 (b) and 1 (c) respectively are spaced apart by respective straight edge portions 11(a), 11 (b) and 11(c). It will be appreciated that different shapes may be used for different tree trunk diameters.

The various embodiments of hood device shown in Fig. 1 are preferably cut from asphalt roofing felt but many other sheet materials are also suitable, for example polymeric sheeting such as sheeting of polyethylene, tin sheeting, aluminium sheeting or foil and plastics material. It will be appreciated also that geometrical curved shapes othere than those specifically mentioned may be used to form a hood device.

When the hood device has been made, for example by cutting from a sheet of suitable material, the device is secured to the trunk of a rubber tree, a typical variety of tree for which the device is of great use being Hevea rubber trees. The sequence of operations involved in securing a hood device 20 to the trunk of a tree 21 is illustrated in Fig. 3.

The first operation, as shown in Fig. 3(a) is to lay the hood device 20 against the trunk of a tree with the centre of the device uppermost so that arm portions extend downwardly from the centre. A layer of adhesive 22 is applied to a lower edge portion the hood device 20 and to an adjoining strip 23 on the trunk 21.

An adhesive which has been found to be particularly suitable is a petroleum based contact adhesive and it has been found that best adhesion is given when the adhesive is left to dry for approximately thirty minutes after application (Fig. 3(b)).

Once a suitable time has elapsed to give optimum adhesion, the hood device 20 is turned round so that the adhesive strip 22 on the hood device 20 faces the strip of adhesive 23 applied to the trunk 21 (Fig. 3(c)). The adhesive strip 22 on the hood device 20 is then pressed against the adhesive strip 23 on the trunk 21 starting from a free end of the hood device and worked along the strips 22 and 23. Once the hood device 20 has been adhered to the trunk 21, the unattached portion of the hood device 20 is bent over to form a hood extending outwardly from and downwardly with respect to the lines of adhesive 22 and 23 along their length.

Sealing of the area of contact between the hood device 20 and the bark of the tree 21 is necessary to prevent water seeping through.

Compounds which are suitable for use as sealing compounds are concentrated latex, tar, grease, rubberised clay and also petroleum contact adhesive. One or more seals may be required depending on the compound chosen.

Fig. 2 shows various views of a hood device 20 secured to a tree, and its relationship with a tapping groove 30.

Preliminary tests have been carried out to compare the effectiveness of a hood device according to the invention with an existing aluminium foil rainguard in the form of a channel. The tests indicate that a device according to the invention is significantly more effective than the aluminium foil channel method. In adhesion trials, petroleum based contact adhesive has been found to be the most effective adhesive although concentrated latex can be an alternative, although less effective than a petroleum based contact adhesive.

Claims

1. A hood device of sheet material for protecting a rubber tree tapping groove, which hood device has a substantially crescent shape defined by an inner curved edge portion adapted to be secured around at least a part of a tree trunk and an outer curved edge portion, in use the hood device providing a surface extending outwardly and downwardly from the inner curved edge portion secured to a tree.

2. A hood device as claimed in Claim 1 wherein the substantially crescent shape is defined by the edge portions being or comprising semi-circles.

3. A hood device as claimed in Claim 1 wherein the substantially crescent shape is defined by the edge portions being or comprising semi-elipses.

4. A hood device as claimed in Claim 1 wherein the substantially crescent shape is defined by the edge portions being hyperbolic.

5. A hood device as claimed in Claim 1 wherein the substantially crescent shape is defined by the edge portions being parabolic.

6. A hood device as claimed in Claim 1 wherein the substantially crescent shape is defined by the edge portions being cycloidal.

7. A hood device as claimed in any preceding Claim made of polymeric material.

8. A hood device as claimed in any one of Claims 1 to 6 made of bitumen based material.

9. A hood device as claimed in any one of Claims 1 to 6 made of metallic sheeting.

10. A hood device as claimed in any one of Claims 1 to 6 made of flexible plastics material.

11. A method of securing a hood device as claimed in any preceding Claim to a tree, which method comprises the steps of laying the hood device against the tree surface with the inner curved edge portion lowermost and a line joining the centres of the inner and outer edge portions lying parallel to the longitudinal axis of the tree, applying a layer of adhesive to the lower edge portion of the hood device and an area of the trunk lying adjacent the lower edge portion, turning the hood device round and adhering the adhesive carrying edge portion of the hood device to the adhesive applied to the tree and progressively folding over the material of the hood device to form a hood.

1 2. A method of securing a hood device as claimed in Claim 11 wherein the adhesive is a solvent based contact adhesive.

1 3. A rainguard of bitumen based material suitable for use on a rubber tree to shield a tapping groove on the tree from rain.

1 4. A rainguard as claimed in Claim 1 3 wherein the bitumen based material is commonly known as asphalt roofing felt.

1 5. A method of securing a rainguard to a rubber tree comprising the step of adhering the rainguard to the tree trunk with a volatile solvent based contact adhesive.

16. A method as claimed in Claim 15 wherein the adhesive is applied both to the rainguard and to the trunk.

17. A method as claimed in Claim 15 or Claim 1 6 wherein the adhesive is left to dry for a predetermined period before application of the rainguard to the trunk.

18. A method of securing a rainguard to a rubber tree comprising the steps of securing the raingaurd to the tree and applying a sealant compound to seal the joint between the rainguard and the tree.

19. A method as claimed in Claim 18 wherein the sealant compound which is bitumen based.

20. A method as claimed in Claim 1 8 wherein the sealant compound is petroleum based contact adhesive.

21. A method as claimed in Claim 18 wherein the sealant compound is grease.

22. A rainguard substantially as hereinbefore described with reference to and as shown in Fig. 1 (a) or Fig. 1 (b) or Fig. 1 (c) of the accompanying drawings.

23. A method of securing a rainguard to a tree substantially as hereinbefore described with reference to and as shown in Fig. 3 of the accompanying drawings.