RELATIVE TOLERANCE OF 20 BASIDIOMYCETES TO BORIC-ACID

Fourteen brown rotting, and six white rotting basidiomycetes were exam ined for their ability to attack blocks treated with boric acid in a s oil-block test. The brown rot fungi most tolerant of boric acid treate d Pinus radiata D. Don were Polyporus verecundus Perk. & Curt., Gloeop hyllum abietinum (Fr.) Karst; and G. trabeum (Fr.) Murr. The most tole rant white rot fungus was Perenniporia tephropora (Mont.) Ryv. for bot h P. radiata and Eucalyptus regnans F. Muell. test blocks. All fungi e xcept G. abietinum were controlled by a boric acid retention of 1.0 kg /m(3), and all were controlled at 2.0 kg/m(3). Sterile control blocks retained 74 - 100% of the original boric acid retentions at the end of the soil-block test, indicating Limited leaching of the preservative from blocks during the test.