A STUDY OF THE PATHOGENE-FREE TECHNIQUE ON SWEET-POTATO WITCHES’ BROOM

During past four years we have done a lot of work on sweet-potato shoot tip culture to eliminate witches’ broom pathogen and finally these plantlets have been observed carefully about their shape-appearances and aminoacid contents, and have beeii tested by graft to compare with those diseased plants, Result showed that 7% of these plantlets were assured of mycoplasmalike organism-free.We are sure this method is worth while in production of sweet-potato. of course, before planting these seedlings the insect vectors-leafhoppers in the field must be cleaned off thoroughly.