Chemical control [fungicides] of cocoa seedling dieback caused by Phytophthora palmivora
1980
Kwee, Lim Tong | Beng, Ang Boon
Three systemic fungicides viz. Ridomil (25% W.P.), Aliette (80% W.P.), and Terrazole (24% E.C.) were screened against a standard Difolatan (39% flowable) for both prophylactic and therapeutic efficacy on 3-4 months old cocoa seedlings. Aliette was tested as a foliar spray at the rates of 0.25% a.i. and 0.4% a.i., Ridomil at 0.5% a.i. foliar spray, Difolatan at 0.2% a.i. foliar spray and Terrazole at 0.1% a.i. foliar spray and soil drench. A water spray was included as blank control. For the prophylactic trial, seedlings were wound-inoculated 3 days after spraying. For testing therapeutic activity, the seedlings were wound-inoculated three days before spraying. Results showed that Ridomil and Difolatan exhibited significantly high prophylactic activity against P. palmivora, followed by Aliette at 0.4% a.i. Terrazole at 0.1% a.i. foliar spray and soil drench exhibited similarly low prophylactic activity as Aliette at 0.2% a.i. For therapeutic efficacy, Aliette at 0.4% a.i. and Ridomil at 0.05% a.i. gave the best results. No significant differences were detected among the Terrazole foliar spray, Terrazole soil drench and Aliette 0.2% a.i. treatments. Difolatan exhibited negligible curative activity.
Показать больше [+] Меньше [-]