Philippine buko is cadang-cadang viroid-free, experts confirm
by Mary Charlotte O. Fresco
BAR TODAY –April-June 2002
Around 80% of our coconut products goes to foreign market, generating US$ 741.77 million a year. This makes us the third largest producer of coconut oil and desiccated coconut in the world. Our young coconut orbuko even performs well in neighboring countries like Taiwan and Malaysia.
This was before export bans were imposed on our coconut products.
In 1998, Brazil was the first to set trade restrictions on our desiccated coconut. Malaysia and Taiwan followed years later by imposing a ban on our buko for fear that it was contaminated with the dreaded cadang-cadang viroid.
In 2000, experts from the Philippine Coconut Authority (PCA) in Albay did a series of rigorous viroid-detection process and declared that the meat and water of young and mature coconuts in the Philippines are free of the cadang-cadang viroid.
Checking the viroid Cadang-cadang was confirmed to be a viroid disease in the late 70s. Its causal agent is the coconutcadang-cadang viroid or CCCVd, which is often transmitted through pollen and seed, and contaminated farm tool such as scythe. Viroids should not be mistaken with viruses because they are much smaller and have different molecular and biological properties.
The disease is common in the Bicol region and also present in some areas in Quezon, Aurora, Biliran (particularly in Maripipi Island), Northern and Eastern Samar.
Researchers MJB Rodriguez and LP Estioko of PCA-Albay Research Center, hoping to exempt the young coconut from the ban, employed a more reliable and sensitive diagnosis for the presence of CCCVd. It is an improved molecular hybridization assay (MHA) that can be efficiently used to detect the concentration of the viroid in different parts of the nuts.
They gathered samples of young (about 6 to 9 month old) and mature nuts (a year old) from both healthy and infected palms and immediately subjected them to CCCVd analysis.
The results The diagnosis made on fresh young coconut or buko was promising. Even if they were obtained from the tree infected with cadang-cadang, the solid (meat) and liquid (coconut water) endosperms were found free of the viroid. The same findings were obtained from the diagnosis made on the samples collected from healthy coconut trees. However, the pericarp (husk) and leaf samples from infected trees were found to have CCCVd.
The cadang-cadang disease, though infectious, is not as serious as it may seem. One interesting fact about this disease is that the viroid degrades through time. Experts proved this true when they observed samples of nuts contaminated with CCCVd under ambient temperature for two weeks.
Results of their observation showed that CCCVd was completely degraded in the young coconuts’ husks after two weeks, while in mature nuts, it only took one week for the CCCVd to be completely degraded in the husk.
According to the researchers, CCCVd contamination in young coconut husks is two times higher than in mature coconut husks because the latter is practically composed of dead tissues.
Furthermore, the chance for young coconut with infected husk is very small in the foreign market due to the marked inferiority in quality and appearance.
Nuts from cadang-cadang diseased palms are much smaller, have an unusually round shape and a scarred surface- the qualities that would not surely meet the standards set for exportable fruits. In Taiwan, for instance, the required weight for an exportable young coconut should not be less than 3 kilos. The nut surface should be smooth, while the meat soft, sweet and tender.
Also, the researchers pointed out that since there is no CCCVd contamination found in the meat and water of both young and mature coconuts, products derived from them such as desiccated coconut, coconut powder, makapuno jelly, nata de coco, vinegar and wine should be exempted from the ban.
The real score The main reason why Taiwan and other countries imposed ban on our coconut products, is the health risks posed by CCCVd contamination.
According to the researchers, there is no known recorded case of health risks or illness resulting from consumption of products contaminated with CCCVd. The restriction made on our coconut products is mainly due to the marked inferiorities in the quality and appearance of the nuts.
Taiwan promised to lift the ban on our coconut products when the Philippines is certified free ofcadang-cadang. But researchers admitted that it is not reasonably possible since cadang-cadang has not been totally eradicated in the country.
The battle for cadang-cadang in the Philippines is far from over. There are studies on cadang-cadangdisease containment program underway to selectively accredit disease-free areas as sources of coconut exports products (for immediate lifting of the ban) and to trace the spread of the disease and eventually formulate ways to completely eliminate it.
Source: Determination of CCCVd contamination in unprocessed/processed coconut export products (1999-2000), a study conducted by MJB Rodriguez and LP Estioko, Philippine Coconut Authority-Albay Research Center, Banao, Guinobatan 4503, Albay, Philipines