ABSTRACT An experimental cocerning the radiation intruction and colchicine concentration on the intensity of purple blotch (Alternaria porri (Ell.) Cif.) and yield of garlic (Allium sativum L.) Lumbu Putih variety was carried out in 24 Februari until 25 Mei 1994. This an experimental was car- ried out Sukarno-Hatta street, South Magelang District, Mage- lang City, Central Java. The kind…