Application of phosphonate to control Phytophthora patch canker of durian in the Philippines

摘要

The use of phosphonate to control Phytophthora palmivora patch canker in durian was tested by trunk injection and bark spraying. An annual 16 g a.i. per tree injection decreased patch canker. Application of either 10% or 20% phosphonate as bark spray with the surfactant Pentra-Bark® also reduced the mean canker rating 17 months after application. The use of phosphonate either as a trunk injection or a bark spray limited further canker damage. Phosphonate application can be integrated into the disease management strategy against Phytophthora in durian. Yield returns also significantly increased in all phosphonate treatments applied. At 210 pesos/tree/year ($US4.00) the cost of bark spraying is higher than trunk injection at 170 pesos/tree/year ($US3.00). The farmers can make further savings using phosphonate, in terms of not having to replace trees killed by canker.