Influences of Fertilization to Selected Economically Important Palms on the Preference of Scale Insect (Aspidiotus Rigidus Reyne)

Abstract

Scale insect (Aspidiotus rigidus Reyne) outbreak threatens the coconut industry and other economically important non-timber forest products like rattan, buri, kaong and anahaw. This research investigated growth, anatomy, and chemical properties of palms that influence their susceptibility to scale insect. Growth parameters (shoot and root length, leaf area, number of leaves, root/shoot ratio, and plant biomass) were measured. Chlorophyll content was determined using Apogee CCM-200 plus Chlorophyll meter. Cell size of the mesophyll layer and thickness of leaf and epidermis on the adaxial and abaxial sides were measured using Image J (1.43m) software. Population count of the coconut scale insect was determined. The silica content in leaves was obtained using SEM-EDX Analysis. Growth parameters except number of leaves, total biomass and root/shoot ratio were highly increased in inorganic than organic and control. Chlorophyll count on coconut was significantly reduced to 36.2%, 41.7% and 13.2% on zero, organic, and inorganic fertilizers, respectively due to insect infestation. Interestingly, the scale insect population was significantly reduced (p < 0.01) by 87% due to inorganic fertilization in coconut but not in other palms. However, organic fertilization encouraged infestation by 56% as compared with 69% reduction in coconut with inorganic application. The amount of silica in leaves was rattan >kaong> buri >anahaw> coconut, suggesting addition of inorganic fertilizer to address scale insect infestation and provide quality palms.