Growth of Pongamia pinnata (L.) pierre seedlings in different potting media

Pongamia pinna/a (L.) Pierre is one a very valuable tree as recent study showed that its seed oil has potential to be processed into biodiesel. This has created a high demand for large amount of planting stocks to meet the commercial planting. Hence the objective of this study is to determine the best soilless potting media or potting mix to produce a healthy P. pinnata seedling in nursery for the plantation. A total of 150 seedlings were transplanted equally into six treatment namely 100% of topsoil (as control) (M I), 100% of composted sawdust (as control) (M2), 100% of coco peat (as control) (M3), potting mix of topsoil and composted sawdust with I:J ratio (M4), potting mix of topsoil and coco peat with I: I ratio (M5) and potting mix of composted sawdust and coco peat with I: 1 ratio (M6). The result showed that the treatments were significantly affecting the seedlings height, however, the treatments do not affecting seedlings stem diameter, total leaf area, leaf number and root shoot ratio. Seedlings growth in M5 had the best height (38.96 cm ± 3.00), stem diameter (5.60 mm ± 0.27), total leaf area (252.90 cm2 ± 33.00), leaf number (II leaves), and root shoot ratio (0.58 ± 0.06). Seedlings that are smaller in size and have small leaves have higher survival rate at planting site. This is because of easy in management and transportation and the transpiration rate is low. In addition. the high root shoot ratio showed that the seedling had good root system. Seedlings that have good root system are more resist to harsh environment. As a conclusion, M5 is the best potting mix for the P. pinnata seedling