Agricultural authorities in Yantai pledge to shut down any workshops producing illegal bags containing pesticide, the city government said in response to a recent newspaper report on the illegal bags some farmers use to protect growing apples.

On June 11, the Beijing News reported that some famers in Yantai, China's major apple growing area, used bags containing prohibited pesticide to cover the apples. Using pesticide inside the bags is an illegal practice.

In September, the Shandong provincial agricultural bureau learned that some farmers use apple bags that contain unknown pesticidelike substance, but tests conducted by the agricultural authorities could not identify the substance, the newspaper cited an official named Su from the Shandong Provincial Agricultural Bureau as saying.

Su claimed the pesticide-laced bags won't harm the growing apples if they are replaced by pesticide-free bags in time.

According to the Fengtai branch of the Beijing industry and commerce bureau, no pesticide residue has been found to exceed permissible levels on fruit from Yantai as of Monday.

Su said professional teams have been formed in Yantai to test the apple bags from the newspaper report.

Fruit bags are often used by growers to cover fruit on the tree while spraying pesticides.