Effect of nutrients combined with inducers of resistance on the protection of cocoa seedlings against witches' broom

Aiming at improving the level of induction of resistance in cocoa, various nutrients, acibenzolar-S-methyl (ASM) and their combination were tested on cocoa seedlings, clone SIC-23, 30 days before inoculation. The commercial products Supa-potassio (R) (potassium silicate), Hortifos (R) PK (potassium phosphite) and Broadacre (R) Mn (manganese sulfate) were sprayed at doses of 2.5, 5.0 mL and 10.0 mL per liter of water, combined or not, with ASM (R) (0.2 g/L). The experiment was set in a randomized block design, in a factorial scheme, with four replicates of twelve plants each. Disease incidence was assessed 60 days after inoculation. Only ASM promoted significant control of the disease. Nutrients alone had no effect on disease incidence. On the other hand, the protective effect of ASM disappeared when this product was mixed to Supa-potassio at 5 or 10 mL/L.