Disease outbreak is not just a concern for people. The agricultural business is also in constant fear of disease outbreaks. Disease-causing microbes of plants have wreaked havoc worldwide.
Together with the plant-killing pests, crop diseases pose major risks in agriculture.
Add to that the threat of natural calamities such as floods, one can understand why many shy away from agriculture.
Stories of crops being wiped out by diseases are not uncommon.
With the changing climate and rising global temperatures, the emergence of new crop diseases has witnessed an increasing trend. The biggest worry is their potential to lower crop yields.
Natural rubber is one crop which has to constantly deal with debilitating diseases. Those affecting the root and leaves are the major ones.
The most lethal on record must surely go the leaf disease which is still endemic in many regions of the host country Brazil. Yes, the dreaded South American Leaf Blight (SALB) has stalked the world's natural rubber industry for years now.
Once a tree is infected, SALB can wipe out an entire rubber plantation. Or in fact, say goodbye to the country’s rubber industry.
There is as yet no viable treatment for the disease. All that has been done is to enforce quarantine measures to prevent the spread. There are strict restrictions in place for all travels from the infected areas in Brazil. The disease spores can be easily carried through travel.
Disinfection measures are vital for travellers out of Brazil going to the main rubber-producing countries of Asia and Africa mainly.
Though SALB has been well-contained through such quarantine, a new leaf disease for rubber has recently created a big scare among rubber growers in the region.
Pestalotiopsis is the name given to the new disease which affects the leaves of the rubber tree. According to records, the disease appears every time during periods of heavy rain.
When infected, the rubber tree will lose a lot of leaves, in the process lowering latex yields by up to 20% in some cases.
So far, no effective treatment has been found.
The other worry is that trees which are infected with pestalotiopsis can concurrently develop other diseases like phytophthora.
Literally all the rubber-growing areas in the major producer countries have reported incidences of pestalotiopsis. Unless research is done to develop a cure, it can further affect the world's production of natural rubber.
Even now, there is concern that the world may not have enough natural rubber to feed the tyre industry.
Very low prices have forced smallholders to abandon their rubber holdings.
Experts in rubber diseases have proposed undertaking collaborative research to find solutions to better manage the disease.
Under the umbrella of the International Rubber Research and Development Board (IRRDB), the research will involve collaboration among scientists from many rubber-producing countries.
According to their submission, any single approach may not be appropriate or suitable in controlling the disease. Chemical control with only fungicide is not sufficient.
They have proposed an integrated approach to tackle the problem. This refers to a decision-based approach involving the coordinated use of multiple tactics to optimise the control of pathogens ecologically and economically.
These may include proper site selection and preparation, utilising disease-resistant planting materials, altering planting practices, modifying the environment by drainage, irrigation, pruning, thinning, shading, and applying pesticides, if necessary.
In addition to these traditional measures, we also need to undertake the monitoring of environmental factors including temperature, moisture, soil pH, and nutrients.
Disease forecasting, and establishing economic thresholds are other important measures to the management scheme.
Accurate diagnosis of the causal agents by following conventional and molecular approaches is urgently needed. Without correct identification and diagnosis, it will be difficult to design an appropriate disease-control scheme.
A thorough understanding of the disease cycle, including climatic and other environmental factors that influence the cycle, and cultural requirements of the host plant, are the other essentials to effectively manage the disease.
There is no doubt that this new rubber leaf disease poses a serious threat to the industry. Climate change is partly to blame.
Research is the only sure way to develop the right solution.
PROF DATUK DR AHMAD IBRAHIM
Tan Sri Omar Centre for STI Policy
UCSI University