RESEARCH ARTICLE

Journal of Oil Palm Research Vol. 5 No. 2 1993 Dec, p. 75-85

THE ROOT SYSTEM OF THE OIL PALM (ELAEIS GUINEENSIS, JACQ.) II: INDIRECT ESTIMATIONS OF ROOT LENGTH, DIAMETER AND SURFACE AREA

GOH K J*; SAMSUDIN Amit*

Received: 4 January 1992  
ABSTRACT

Direct measurements of oil palm root length, diameter and surface area are time consuming and laborious in the absence of a sophisticated image analyser. A study to examine indirect estimations of these root parameters with and without elutriation was therefore conducted.
The results showed that two non-elutriation methods (which were extensions of Tennant’s formula and Drew and Sakers’ method respectively) did not provide accurate estimates of root length per soil core. The correlations between direct measurements of root length and lengths obtained by each of the above methods were low.
Root length per soil core could be estimated from root dry weights by regression if the roots were categorized into different diameter classes: primary roots > 7 mm (XI), 4-7 mm (X2) and < 4 mm (X3); secondary roots > 1.2 mm (X4) and < 1.2 mm (X5); and feeder roots (X6). Their coefficients of determination (r2) ranged from 0.86 to 0.95.
Step-wise regression analysis showed that total root length (cm) per soil core (Y) could be estimated by the equation:
Y = 15.8 + 14.2 X3 + 95.6 X4 + 364.9 X5 + 394.6 X6 with an r2 of 0.91.

Root diameters and surface areas were also highly correlated with root dry weights.

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* Applied Agricultural Resources Sdn Bhd,
Locked Bag 212, Sg Buloh Post Office,
47000 Sg Buloh,
Selangor, Malaysia.