DEVELOPMENT-NIGERIA: Cassava Disease Threatens Food Security

By Toye Olori Reprint | | Print |

Toye Olori

EJIOKU-IBADAN, Nigeria, Jun 23 2003 (IPS) - Tunji Adelakun, 57, sits dejected on a bench in front of his thatched hut, complaining about the loss of his cassava crop to a devastating disease that twists the leaves and turns them yellowish.

"For sometime now, I have not been able to harvest good cassava roots from my farm because of the disease. Before the outbreak of the epidemic, I used to have bumper harvest, sell the surplus and buy with essential goods. But all that is gone now,” says Adelakun.

The visibly worried farmer says he can hardly make enough money from his farm to educate his six children.

”I am thinking of cultivating other crops on this farm. My friends, who cultivate maize and yam, have advised me to follow their steps. But I need a larger farmland to be able to grow maize and yam which are seasonal unlike cassava,” Adelakun told IPS at the weekend.

Last year President Olusegun Obasanjo announced that the government would encourage the mass cultivation of cassava, or manioc, and export the pellets.

The disease, which is giving farmers sleepless nights, is the Cassava Mosaic Disease (CMD), which makes the leaves twist and produces the characteristic yellow-green ‘mosaic’, resulting from the loss of the vital chlorophyll needed by the plant to harness the sun’s energy for its growth. It routinely reduces African cassava production by 15 to 25 percent for most of the time, according to crop scientists in Nigeria.

Nigeria, the largest producer of cassava in the world – over 33 million metric tonnes from an area of 3.1 million hectares – accounts for 70 percent of the total production in West Africa.

The crop is the most widely cultivated in the south of the country in terms of area devoted to it and number of farmers growing it. It is planted predominantly by smallholder farmers, but cassava has become popular as a food and cash crop in the country.

As a result of its year-round availability, tolerance to extreme ecological stress conditions and impoverished soils, cassava plays a major role in efforts to alleviate food crisis and rural poverty.

Opportunities for commercial development, however, remain largely undeveloped in contrast to the other major zones of cassava cultivation in Asia and South America. In Nigeria, it currently contributes to the feeding of the majority of the country’s 120 million people.

Scientists at the International Institute of Tropical Agriculture (IITA) in Lagos revealed that the disease was first noticed in Uganda, East Africa, in the 1980s. It has now reached West Africa.

Recent diagnostic surveys show the occurrence of the East African Cassava Mosaic Virus (EACMV) in Nigeria, Cameroon, Togo and Ghana and a combination of the EACMV and the African Cassava Mosaic Virus (ACMV) in Nigeria and Cameroon.

”Mixed infections of EACMV and ACMV and their variants are common in cassava fields sampled in Nigeria, especially in the humid forest zone and in Southern Cameroon, which can cause increased severity of symptoms and significant yield reductions,” says Taiye Babaleye, spokesperson for the Ibadan-based International Institute of Tropical Agriculture.

”The Cassava Mosaic Disease (CMD) is a chronic limitation on the production of cassava in Africa. By 1999 a pandemic of an unusually severe form of CMD has expanded to Central African Republic. It is now discovered that there is a southward and westward spread of the pandemic in Africa, as well as the presence in Nigeria of the two viruses that recombine to give rise to the virulent strain causing the severe form of CMD,” he says.

Babalaye says scientists at the institute have developed and tested improved varieties of cassava that are resistant to the virulent strains of CMD to stave off the epidemic.

The varieties, he says, are being multiplied in parts of the country in collaboration with the National Agricultural Research Systems. They will be distributed to farmers in zones that are considered prone to the epidemic.

”An outbreak of this disease could immensely lead to serious decline in cassava yield, thus leading to food insecurity, reduced incomes for smallholder farmers, high cost of food for consumers and subsequently social tension,” Babaleye says.

”In view of the importance of cassava in Nigeria, coupled with its potential to serve as an engine for future agricultural development, threats to production must be considered very seriously,” says Olu Omosaiye of the United Nations Industrial Development Organisation (UNIDO) office in Lagos.

The disease, says Omosaiye, is capable of wiping out a whole year’s cassava yield. ”That is why all the state governors (in the cassava producing zone) are collaborating with the IITA and the Committee on the Presidential Initiative on Cassava Production in Nigeria to avert the epidemic,” he says.