Effects of container shape on seedling growth of Hevea brasiliensis

Effects of container shape on seedling growth of Hevea brasiliensis at different growth stages were observed to provide reference for rubber nursing. Rubber seedlings were planted in different shape containers with same height and volume. Then leaf whorl, stem diameter, plant height, tap root length, amount of first lateral root, root weight, shoot weight and root- shoot ratio were investigated at 90, 180 and 360 days after transplantation, respectively. The results showed that the optimal selection of container shape is the prism at 90 days, while the cube at 180 and 360 days. At 90 days, leaf whorls and root weight in prisms were significantly 10.3%, 11.3% more than in cylinders, plant height 13.4%, 20.6% higher than in cubes and cuboids, shoot weight 67.1%, 58.8%, 14.5% heavier than in cubes, cuboids and cylinders, respectively. At 180 days, stem diameter in cubes was significantly 16.4%, 10.9% bigger than in cuboids and prisms, plant height 16.5% higher than in cuboids, tap root length 18.5% longer than in cylinders, numbers of first lateral root 22%, 25%, 56.5% more than in cylinders, prisms and cuboids, shoot weight 23.5%, 40.4% and root weight 19.9%, 19.5% heavier than in prisms and cuboids, respectively. At 360 days, plant height in cubes was significantly 11.7% higher than in prisms and tap root length 14.7% longer than in cylinders. Based on specific surface area of containers and the growth at all days, the optimal selection of container shape is the cube and then the cylinder.