Effect of Temperature, Seed Size, Sowing Depth, and Position on Seed Germination and Seedling Growth of Bauhinia retusa Roxb. and Bauhinia variegata L.

Abstract

In urban forestry plantations are implemented in different cities of the world for social and environmental benefits. Bauhinia retusa and Bauhinia variegata are important species and to be used as large-scale plantation programs in urban forestry which might solve or mitigate urban, social, and environmental issues such as improving the physical & mental health of residents, food and nutrition security, increasing urban biodiversity, cooling the neighboring, preventing soil erosion, flooding, and mitigating greenhouse gas emissions and air pollution. The present study was conducted with the aim of producing quality planting material for B. retusa and B. variegata in the nursery for afforestation programs. Seeds of B. retusa and B. variegata were collected from the natural habitats to assess seed germination and seedling growth. Seeds were stored in different types of containers at room temperature and later on exposed to 15, 20, and 25 °C in seed germinator. Seeds were further sown in polythene bags according to the seed size, seed coat color, seed sowing depth, the orientation of seeds, and the result of the emergence of seedlings, their growth, and biomass were estimated. A two-way analysis of variance was calculated to estimate the variation among the studied parameters. Results revealed that a constant 25 °C temperature was considered best for seed germination of both the Bauhinia species. Polybags were found the most suitable for storing the Bauhinia seeds among the storage containers. The seedling emergence and growth were maximum in yellow color and large seeds. In B. retusa, seedling emergence, and growths were the maximum in seeds sown at a horizontal position and in B. variegata at an upright position. Seedling emergence, length, and biomass were recorded the maximum when seeds of B. retusa were sown at 4 cm depth and B. variegata seeds were sown at 2 cm depth. The study recommends that the yellow color seed that has to be sown at 2 cm to 4 cm depth with upright and horizontal positions is considered best for the production of quality planting stock of both studied Bauhinia species.