Chinese scientists say they have had a breakthrough in identifying plant diseases that are frustrating attempts by farmers to grow kiwifruit to meet the vast domestic and global demand.

Researchers at Wuhan Botanical Garden under the Chinese Academy of Sciences have recently identified three key fungi that can kill fruit, destroy flavor and reduce production, according to local media Xinhua.

For the last year, they have studied kiwifruit in Guizhou, Zhejiang and Yunnan provinces, important growing regions where diseases are reported more frequently than other areas.

Research leader Li Li said most orchards in southwest China's Guizhou are at high altitudes, where local fruit has a higher sugar accumulation due to the temperature difference between day and night. The sweetness makes fruit more vulnerable to pests and diseases.

Neighboring province Yunnan has high temperatures in winter and coastal province Zhejiang is rich in rainfall, so epidemics are hard to prevent and control.

Researchers found that nigrospora sphaerica - a fungus that causes post-harvest rot - can make the kiwifruit skin softer and flesh soggier. It is the most severe fungal disease in Chinese kiwifruit orchards. The incidence in many provinces such as Sichuan, Shaanxi, and Hunan is between 20% to 50%.

Healthy kiwifruit can be stored for four to eight months at low temperatures, but fruit infected with such diseases can last only six to 10 days.

Previous studies have shown that the fungus can also attack apples and pears, Li was quoted as saying.

The other two newfound funguses, alternaria tenuissima and didymella glomerata cause diseases in leaves and fruit, which speeds up rot and cut production.

The study, published in the international journal Plant Disease, could help develop new fungicides.