19 Jul 2010
Mysterious cocoyam leaf disease causes panic in Cameroon
It started as a rumor that a family of three died after eating disease- afflicted ‘Igbo’ cocoyams (a local name given to a variant of cocoyam specie). It was later confirmed that a strange disease is attacking the leaves of species of cocoyams and causing them to rot or dry but there was no way of linking the rumored deaths to this particular outbreak. Panic and confusion then took center stage as the news spread that a local administrator had announced the ban on consumption and sale of the specie of cocoyams. Initially, it was thought that the strange disease was limited to the South West region of Cameroon but it soon emerged that many cases were reported in the Littoral and North West Region and beyond.
As time progressed, so did the explosion of scary rumors. The origin of the mysterious crop disease was attributed by some to the hazy weather experienced in Cameroon a couple of months ago while others alleged that it was caused by fallouts from a bomb used in another country. Conspiracy theorists had a field day churning out multiple theories.
Images 1&2: Two different morphologies of common cocoyam leaves in Cameroon. Image 3: Fungus selectively attacks type of leaf in image 2. Image 4: Advanced state of leaf rot.
There are many who stopped eating cocoyam tuber and leaves and many who actually believed the unfounded rumor that the two hands of a woman were amputated in the hospital due to complications linked to physical contact with a sick plant. I talked to some women in Batibo who confirmed that they abandoned sections of their farms that were affected by the crop disease for fear of unknown consequences. My advice to them was to continue handling and consuming all cocoyam specie as before. By the time of writing this piece, local administrators were already advising people to continue eating all species of cocoyams.
I did make inquiries from a crop expert and he promised to link me up with a specialist on cocoyams. As the waiting was a little bit longer than I expected, I decided to do findings on my own. After visiting five affected farms in Batibo and talking to about a dozen farmers, I made further findings and came to the conclusion that the disease in question is Taro leaf blight caused by the fungus Phytophthora colocasiae . Further findings show that this disease has been reported in the following countries Indonesia, Hawaii, Thailand Solomon Islands, Samoa, American Samoa, Papua New Guinea and the Philippines. Reports say that the fungus is propagated by water and wind.
The intriguing thing is that the disease came abruptly and the geographical spread is large (I can confirm its presence in three of Cameroon’s ten administrative regions).
I write not as an expert in this field and as such I will welcome anybody that can challenge my conclusions on this topic. I will also like those who are more knowledgeable on this issue to answer the following questions (if my conclusions are accepted);
1. How did a crop disease that is endemic to South East Asia find itself in Cameroon?
2. How come the appearance on the Cameroon scene is abrupt and widespread?
Njei Moses Timah