Do not allow rain to interfere rubber tapping and lower your income levels

Dr. Asoka NUGAWELA

A major factor that lowers the income levels of rubber growers and latex harvesting officers is the interference of rain on tapping. Rain is a hindrance for the latex harvesting officer to tap. Further if a wet rubber tree is tapped it leads to panel diseases.

Due to above reasons around 140 days of tapping is lost each year. Since one tapping block is recommended to be tapped once in two days the loss of tapping days in a tapping block is around 70 per year. In average a tapping block consists of around 300 trees and gives a yield of around 9kgs per tapping.

Therefore for 70 days the loss of crop is about 630kgs. The current price of a kilogram of natural rubber is around Rs. 250 and hence the monetary value of the rubber not harvested due to rain is around Rs. 157,500 per annum per tapping block. This is a significant loss for both land owners and the latex harvesting officers.

If the recommendations to overcome the interference of rain on tapping are adopted with confidence this huge monetary loss both to the growers and latex harvesting officers could be avoided. This will undoubtedly boost the income and living standards of both rubber growers and latex harvesting officers.

Annual loss

If the value of rubber not harvested from a single tapping block is Rs. 157, 500 per annum the loss to the country from the entire rubber plantations is a fact that should draw the attention of all concerned. It is estimated that the annual loss is around Rs. 14,500 million and this undoubtedly demands the attention of all concerned to make a concerted effort to overcome this huge loss to the rubber growers, latex harvesting officers and the country.

The rubber growers on their own react to this situation in a number of ways. A popular approach is to tap the rubber trees continuously when weather conditions permit to do so.

As a result a tapping task is tapped continuously during dry months. With this method the desired objective of the land owner, i.e. recovering the crop loss due to not tapping in wet days, cannot be achieved.

This is because once the crop is harvested from a tree a certain period of time should be given for it to re-synthesize the latex prior to harvesting it again. This is why a rubber tree is recommended to be tapped every other day. Therefore daily tapping results in a major stress to the rubber plants.

Daily tapping leads to a lowering of the dry rubber content of latex and in such trees if tapping is undertaken continuously it leads to a cessation of latex production. This situation is referred to as tapping panel dryness and in the rubber plantations in the country this incidence is high as 15-20%.

Undertaking late tapping is another strategy the growers adopt to minimise crop losses due to the interference of rain on tapping. Late tapping is commencing of tapping late in the day once the wet panels of rubber trees have dried-up. In this manner about 40-50 out of ca. 140 tapping days lost per annum due to rain could be recovered.

Tapping

Nevertheless, late tapping results in about 25% loss of crop when comparing with normal tapping. Hence when considering the number of tapping days we are able to recover and the crop loss in such days this approach is not a complete remedy for the issue.

However, it is a better method than undertaking daily tapping on dry periods of the year. But it is apparent that the latex harvesting officers are reluctant to undertake tapping on late tapping days.

During rain the water is collected on the canopy of tree and it comes seeping along the trunk. During the process the mosses found on the trunk of the rubber tree absorbs part of this water. The water absorbed by mosses in this manner is released only gradually. Thus the tapping panel of the tree remains wet for a considerable period of time even after the rain has seized.

This situation could be avoided by grooming, i.e. the removal of the mosses by scraping the trunk on upper, lower and lateral sides of the tapping cut. This quickens the drying up process of the wet panels. Nevertheless, this method is only very rarely adopted by the rubber growers.

However, it should be mentioned that the most appropriate method to minimise crop losses due to the interference of rain on tapping is to adopt the technology of rainguarding. This method is a complete answer to the problem and is widely adopted in the rubber plantations of our neighbouring country India.

Among the rubber growing countries in the world the land productivity is the highest in India and the use of rainguards would have contributed to this significantly. Though the use of rainguards is in the increase in the country it is still at a lower percentage of the total extent. An encouraging trend is that those who have realised the gains from this exercise continue to adopt it each year.

Rainguards

As mentioned before when comparing with neighbouring India use of rainguards is at a lower rate in Sri Lanka. Though growers in Sri Lanka come out with various excuses why not to adopt rainguards none of them can be accepted as correct.

A major issue raised is that the rainguard results in the condensation of water on the tapping panel and then it leads to infections and tapping panel dryness. The condensation of water is said to take place due to the covering of the entire circumference of the tree with the rainguard preventing any ventilation.

But with the correct adoption of the rainguard technology sufficient space is made available in the rainguard to provide the necessary ventilation to prevent any condensation of water and infections.

Tapping rest

Some argue that even with alternate day tapping, exploiting of rubber trees without intervals of non-tapping can bring about a stress condition to the tree and hence rubber trees should not be tapped when there is rain interference to provide that interval.

Nevertheless, extensive research has found out that tapping at alternate day frequency has no detrimental effects to the tree. If a rubber tree is stressed due to tapping the dry rubber content of the latex obtained will drop to levels below 30%.

If such a situation occurs it is advisable to give the trees a tapping rest for 6-8 days. Anyhow, it should be mentioned that even with rainguarding about 20-30 days of tapping are lost per annum due to days with continuous rain.

With the installation of rainguards the area of the tree covered by the rainguard will remain dry whilst the other areas of the tree will remain wet during rainy periods.

Though some believe that this condition is not good for the tree there is no scientific basis for this belief. Latex harvesting officers in some instances discourage the land owners from fixing rainguards.

This is purely because they will have to perform some additional work during tapping of rainguarded trees. The additional work is to lift the rainguard prior to tapping and to lower it on completion of tapping.

This so called additional work will not take more than 2-3 seconds per tree. With proper rainguards in place a minimum of 100 tapping days out of nearly 140 tapping days lost in a year due to rain could be easily recovered.

The gain from this to the latex harvesting officer will be much more than the disadvantages if there are any. Anyhow, the rubber land owners should motivate the latex harvesting officers to use rainguards. This could be done by providing them with raincoats, leech repellents and also paying an incentive for tapping on days if otherwise would not have been possible.

Government programmes

In some instances though the landowner is for fixing rainguards certain factors prevent him from doing so. Non-availability of the rainguard sealant and lack of skilled workers for fixing rainguards are some of the constraints faced by them. The fact that the landowner has to invest ca. Rs. 25-30 on a tree each year also appears to be a constraint.

It is the responsibility of the relevant departments to ensure the availability of rainguard sealant and to train workers to make them skillful in fixing the rainguards.

These government departments have their own programs to provide these services and the relevant information could be obtained through their field officers or getting in touch with either their regional or the head office.

For installation of rainguards the investment on a single tree is about 25-30 rupees each year. What will be the return on this investment? Long-term studies have revealed that with proper installation of rainguards a minimum of 100 out of the 140 tapping days lost each year could be recovered. Since a rubber tree is generally tapped every other day this will mean that each tree will get 50 additional tapping days due to rainguarding.

An average tree is capable of giving 30 grams of dry rubber per tree per tapping. Therefore for 50 days the additional yield due to rainguards will be 1500 grams or 1.5 kgs of rubber.

With the current rubber price of about Rs. 250 per kg the additional income for the land owner due to rainguarding will be around Rs. 375 per tree per annum. An annual return of Rs. 375 for an investment of Rs. 25-30 is remarkable. This could even be the best possible investment in the Agriculture sector of the country to-day.

Due to this significant return on investment this is an area where the banking sector of the country could assist the rubber growers.

Each year the rubber growers complain that they are unable to harvest their rubber due to the interference of rain on tapping. Further they believe that this is a major factor contributing to the shortage of latex extraction officers in the country today.

Rainguards technology

The most popular method adopted by the growers to overcome this problem is to undertake tapping when weather permits leading to daily tapping.

As discussed earlier this method is unable to deliver the desired objectives of the growers. It should be emphasized that the growers should now adopt the technology of rainguards in their cultivations rather than highlighting the problems repeatedly each year.

Fixing of rainguards should be commenced early in the year and completed before the onset of the monsoons in late April. Such rainguards could be used until they are installed again in the following year during the same period. For this purpose you could get in touch with either the field staff of the Rubber Research Institute, Rubber Development Department or the Thurusaviya Fund or their Head Offices.

With the adoption of rainguard technology the growers are able to harvest high yields for prolonged periods of time. Hence it will be a wise investment made by the growers to enhance their income levels and living standards. The additional income to the grower will enable him to improve the income levels and living standards of the latex extraction officers as well.

This will be an incentive for the latex extraction officers to continue working in the rubber smallholdings and plantations. Further with such investments each and every rubber grower will be effectively contributing to the economic development of the country as well.

The writer is Director of Rubber Research Institute of Sri Lanka