BEIJING - An expert with the Chinese Academy of Agricultural Sciences (CAAS) said Friday multiple factors have caused watermelons to burst in East China's Jiangsu province this month.

More than 700 mu (46.7 hectares) of watermelons are reported to have been ruined due to the problem in the city of Danyang in southern Jiangsu in May.

Zhang Chaoxian, a researcher with the CAAS, told Xinhua one factor was because the variety grown in the city has thin rinds that break more easily. This variety was introduced to the local farmers last year.

The second factor was due to the sudden rainfall after a prolonged drought had plagued the province since spring. The watermelons became easier to burst after absorbing large amounts of rain water following a long period of dry weather.

Zhang also said poor timing in the application of growth accelerators by the local farmers also caused the melons to explode.

These growth accelerators, including forchlorfenuron and gibberellin, should be applied earlier while the local farmers in Danyang applied them when the watermelons were almost mature, causing the melons to burst.

Growth accelerators have found wide applications in agriculture and forestry around the world. Forchlorfenuron and gibberellin are also widely used on plants in China.

Zhang said the growth accelerators, if used properly, can make fruits  grow bigger and more quickly, thus helping raise output. Zhang added there has been no scientific evidence so far proving the chemical residue on fruits can cause harm to human health.