GUANGZHOU: "Quite possibly the world's perfect fruit" is under threat in South China, and till now is without any shield of protection.

The banana plant, erroneously called tree, is being wiped out on thousands of hectares by "banana cancer" in Guangzhou and other areas of Guangdong Province.

The Panama disease (or banana wilt) has been wreaking havoc in Southeast Asia, especially Indonesia, for more than the past half a decade, and could devastate banana plantations in China, if it goes unchecked.

In fact, many international experts fear the disease could wipe out bananas from the face of the Earth in the next couple of decades.

The "cancer" has already affected 38.5 percent of the 8,667 hectares under banana plantation in Guangzhou, including its major bases in Panyu, Zhongshan and Nansha, and is spreading. In fact the first case in Guangzhou was detected as early as 1995.

But bananas on sale in the markets are absolutely safe for human consumption, South China University of Agriculture professor Chen Houbing says, because plants attacked by the disease wilt before bearing fruits.

Guangdong has about 120,000 hectares under banana plantation, 5 percent of which are already under attack by the fungus that causes the Panama disease, Chen says.

The alarming fact, says Liu Shaoqin, director of Guangzhou Association of Science and Technology, is that after about 5 percent infection in the first year, the disease could spread more than exponentially. The second year could see 20 percent of a plantation being affected, and the third, up to 50 percent. An entire plantation could be wiped out by the fourth year.

"Millions of banana plants have died, and unfortunately we have found no cure for the disease," Liu says.

Besides Guangdong, banana plantations in neighboring Fujian, Hainan and Guangxi, which are major banana production areas of China, too, have fallen victim to the disease.

But an expert with the Ministry of Agriculture, Zhang Xiyan has allayed fears: "Banana plantations won't disappear completely if all necessary precautionary steps are taken."

Farmers should dig out the roots of the stricken plants, burn them on the spot and disinfect the soil. And to prevent the spread of the disease, they should mix lime with the soil.

The disease can be combated by flooding the plantation for six months, or, if it's not too serious, by planting a cover crop.

The fungus originates in the soil, travels to the secondary roots and enters the corm through fresh injuries. It passes into the pseudo-stem and starts turning the leaves yellow starting with the oldest at the base first, then along the margins, and finally at the center. The interior leaves turn bronze in color and droop, and the pseudo-stem turns brown.

This disease has seriously affected banana production in Central America, Colombia and the Canary Islands. It started spreading in southern Taiwan in 1967 and has become the worst local banana disease.

"Cavendish" bananas are considered resistant, but they succumb to the disease if planted on land earlier occupied by "Gros Michel". Incidentally, "Gros Michel" bananas were the most favored in the West till the mid-60's when they were attacked by the disease and replaced by "Cavendish".

Source: China Daily