A STUDY ON THE EFFECTIVENESS OF LIQUID SMOKE PRODUCED FROM PALM KERNEL SHELLS IN INHIBITING BLACK POD DISEASE IN CACAO FRUIT IN VITRO

Abstract

The effectiveness of liquid smoke made from palm kernel shells in inhibiting black pod
disease (Phytopthora palmivora) in cacao fruit was studied. Palm kernel shells underwent pyrolysis in a
slow-pyrolysis reactor at 280°C–400°C. The resulting liquid smoke was then distilled at a temperature of
200°C. The observed parameters were incubation period and spotting diameter. The experimental design was
completely randomized, with a 4 × 6 factorial pattern having four repetitions and consisting of two factors.
Both temperature and concentration significantly affected the incubation period of the fungi causing black
pod disease. Additionally, the liquid smoke concentration had a strong influence on the spotting diameter.
Phenolic compounds and acetic acid contained in the liquid smoke serve as antimicrobials and are
bacteriostatic. Although the maximum phenol level was found at 280°C, the longest incubation period
occurred in liquid smoke produced at a pyrolysis temperature of 360°C. Thus, 360°C was the optimum
temperature for producing liquid smoke to inhibit black pod disease caused by P. palmivora in cacao.