Gmelina arborea Roxb. Seedlings Treated at Elevated Temperature in Plant Growth Chamber

Abstract

Elevated temperature has positive and/or negative effects on seedlings of forest trees. Aim of the study was to compare the impact of three higher temperature conditions with control temperature to Gmelina arborea Roxb. (family: Verbenaceae) seedlings growing in a plant growth chamber. Similar sized seedlings randomly selected from same origin were treated with three elevated temperature (30/20, 32/22 and 34/24°C) and compared with control temperature (26.31/16.54°C) at a day/night combinations. Measurements were made for height, collar diameter and increase or decrease of leaf number of the studied seedlings during the observation period. Seedlings height growth was found positive for the examination period rather favourable to elevated temperature conditions than control. Seedlings grown at three successive elevated temperatures showed significantly (p#0.05) higher growth than control temperature. However, collar diameter growth was found insignificant with respect to temperature treatment and days. Number of leaves development was found negatively responded to elevated temperatures. With successive elevated temperature, leaf shedding increased significantly which might be due to maximum thermal entropy given to plants. Thus, elevated temperature might increase seedlings shoot height significantly, where, leaf number might negatively react; leading them to a long seedling with less leaves.