Abstract:
Background and Objective: Cashew nutshell oil (CNSL) is a biopesticide that is
environment-friendly in controlling ants Iridomyrmex cordatus as a Vector pot rot
disease caused by Phytophthora palmivora. The research aimed to obtain the best
concentration of cashew nut shell oil formulated as smart food bait to tackle the ant
population of Iridomyrmex cordatus due mainly to a vector of Phytophthora pod rot.
Materials and Methods: The research was carried out in cocoa areas in South Sulawesi
with a randomized block design consisting of six treatments. Feeding trials consisted of
food bait formulation was added with cashew husk respectively are 1%, 10%, 20%, 17.5
g carbaryl (recommended dose), and control (without cashew husk or carbaryl). Each
trial was replicated five times and set near to petiole and ant tunnel nest. The research
focused on the number of ant colonies established in the trees until food bait was given.
Results: The trial with CNSL concentration had a positive effect on the ant population
which was the higher concentration was given, the lower the ant population was obtained.
Meanwhile, the population of I. cordatus had a positive contribution to the increase of
disease incidence of Phytophthora pod rot disease. Feeding trials with 1 and 5% CNSL
concentrations were less effective to limit ant population and disease incidence according
to the efficacy test. In contrast, the trials of 10 and 20% were able to control ant
population density and disease incidence due to over 51.39% efficacy test. Conclusion:
There was a positive trend of CNSL concentration to reduce the ant population of I.
cordatus. There was the greatest association between the increase of ant population
density and the increase in disease incidence of Phytophthora pod rot.
Keywords: Feeding trials, food bait, CNSL, Iridomyrmex cordatus, Phytophthora pod rot