Preliminary Studies in Integrated Management of Phytophthora Crown and Root Rots
Thomas. T
Archives of Phytopathology & Plant Protection ; 2001 [Vol.34] Pages:211-222
Abstract
Radial growth of Phytophthora cactorum and P. citrophthora was inhibited by T. harzianum and reduced by P. expansum and A. radiobacter, B. cereus did not influence the mycelia] growth of both Phytophthora species. Disease resistance on P. cactorum was induced by a local pre-inoculation with the non-pathogen P. megasperma, P. capsici, or P. drechleri. Besides, it was shown that crossprotection is not systemic but is localized in the area of original inoculation. The influence of heat and flood in the defense mechanisms of peach tree to P- cactorum, P. megasperma, P. capsici, and P. drechleri was also evaluated. Development of P. cactorum on plants was not influenced from any treatment. P. megasperma developed little necrosis only on stressed plants. In contrast, P. capsici and P. drechsleri had not the ability to infect heat and flood-treated plants. Metalaxyl and dimethomorph inhibited the mycelial growth of both Phytophthora species at rates of 10 ppm but not the growth of antagonists. I n contrast, fosetyl-Al inhibited radial growth of antagonists and both Phytophthera species at concentration as high as 500 ppm. Based on these results, metalaxyl and dimethomorph may be good candidates for integrated approach to manage Phytophthora diseases.
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