Canning peach decline in Western Australia. II. Methods of prevention

Abstract

Previous observations on commercial plantings of the South African canning peach variety Keimoes have linked decline with the entry of a complex of fungi into uncallused pruning wounds and dead crotch bark compressed between scaffold limbs. In field experiments we confirmed that hard winter pruning and narrow crotch limb angles induced crotch wound and pressure cankers. This canker formation and subsequent tree decline was prevented by summer pruning, training trees with wide crotch angles to prevent the formation of compressed dead bark between scaffold limbs, and by the autumn application of an unneutralized spray of copper, zinc and manganese sulfates which inhibit the growth of the fungal invaders. Irrigation and fertilizer treatments had no significant effect on tree health.