Seasonal variation in root distribution pattern of teak (Tectona grandis Linn.f.)

Abstract

Studies were undertaken to elicit information on the root distribution pattem of Tectona grandis in three different age classes (three, five and seven year old) and in three distinct seasons viz., summer, rainy and winter to compare the seasonal variation. Root distribution study was carried out with monolith method which involves the partial excavation of soil sample to represent the whole part of the rooting volume of the tree. After removal of soil in three distances (50 cm, 100 cm and 150 cm from tree base) of four depth categories (0-15 cm, 15-30 cm, 30-45 cm and 45-60 cm), the samples were washed separately for the collection of roots. Among the three seasons of observations, rainy season recorded the maximum rooting intensity, root density and root biomass followed by winter and summer. The results revealed that increase in distance and depth led to decrease in root activity by reduced rooting intensity, root density and root biomass. Maximum rooting intensity (457.67 m^-2) was observed in five year old trees at the 50 cm distance of 15-30 cm soil depth category during rainy season. The maximum root density of 0.0201cm.cm^-3 was registered in 100 cm distance of 45-60 cm soil depth category in five year old trees during rainy season. Significantly higher root biomass of 561.67 g. M^-3 was recorded in 50 cm distance of 30-45 cm soil depth category in seven year old trees during the rainy season.