SURVIVAL AND GROWTH OF PTEROCARPUS MACROCARPUS PLANTED BY STUMPS AND CONTAINERIZED SEEDLINGS

Abstract

Field investigation was carried out at field station of the Reafforestation Research and Training Project, Nakhonratchasima province. The planting site was shifting cultivated area derived from dry evergreen forest, 650- m altitude, 1,347- mm annual rainfall, and red yellow podzolic soil. Because of slope, randomized block design was employed having 3 treatments and 3 blocks. Planting materials were considered as treatment: 6- month- old seedling (S₁) 12-month-old seedling (S₂), and 12-month-old stump (S₃). Survival, total height, and girth at breast height (gbh) of Pterocarpus macrocarpus planted in spacing of 2×4 m were recorded at 3, 7, 11, and 15 months old. Growth data were used for periodic annual increment (PAI) and relative growth rate ( RGR) interpretations. The results showed that survival percentages of S₁, S₂ and S₃ treatments at 15 months old were of 96, 95 and 84, repectively, leading to highly significance. Although girth PAI, height PAI, and height RGR did not differ among treatments, girth RGR was found to be significant. Maximum girth RGR was recorded for 12-month-old stump (3.24 cm/yr), followed by 12-month-old seedlings (2.34 cm/yr), and 6-month-old seedling (2. 22 cm/yr). Based on the current findings, stump planting was recommended for Pterocarpus macrocarpus.