Treatment ID

Treatment Name

Best-fit Equation

Correlation coefficient (R²)

T1

Rubber Nut Shell

−9E−05x³ + 11.175x² − 482725x + 7E+09

0.9881

T2

Rice Husk

−8E−05x³ + 10.368x² − 447892x + 6E+09

0.9893

T3

HP wood

−9E−05x³ + 11.551x² − 498975x + 7E+09

1.0000

T4

Control

−7E−05x³ + 9.1344x² − 394582x + 6E+09

0.9224