Philippine E-Journals

Chlorophyll Content, Cell Size, Growth and Resistance to Coconut Scale Insect (Aspidiotus rigidus Reyne) of Buri Palms (Corypha utan Lam.) as Influenced by Different Hoagland Concentrations

Lourdes B. Tayrus | Willie P. Abasolo | Nelson M. Pampolina

Discipline: Ecology

 

Abstract:

Buri palms (Corypha utan Lam.) is the third most important non-timber forest resource of the Philippines because of its multiple uses. It is now being threatened by the coconut scale insect (Aspidiotus rigidus Reyne) epidemic due to its similarity to coconut palms. In order to protect this very important resource, this research was carried out to determine the effect of different Hoagland concentration on the growth and resistance of buri palms to coconut scale insects. Chlorophyll content was determined using Apogee CCM-200 plus Chlorophyll meter. Cell size of the mesophyll layer and leaf thickness was measured using Image J (1.43m) software. Similarly, shoot length, root length, leaf area and plant biomass was measured. Coconut scale insect count was also performed. Chlorophyll content and leaf thickness were unaffected while cell sizes of the mesophyll layer were significantly increased with varying Hoagland concentration. Interestingly, insect count was significantly affected by the treatment. Plants grown in 50% Hoagland solution gave the highest insect population at 71, twice as much as that of 100% concentration with only 36. Treating the plant with 100% Hoagland solution induced the formation of raphides crystals of calcium oxalate on the leaf surface. This provided an added protective layer on the leaf that made it less preferred by the insect. For this reason, improving the nutrition of the plant is a better and safer alternative to reducing the susceptibility of buri palms to coconut scale insect attack.