peat soil
2.The new substratum proportion is vermiculit 4:peat soil 1:slag 1:plant ash 1:farfural residue 1.The test result showed that the new substratum formula can effectively control the occurrence of S.scabies of virus free microtubers,and meanwhile increase nutrition of the substratum. The marketable rate of microtubers produced in this substratum was apparently high and the production cost was reduced.

