Optimum Depth of Sowing for Propagation of Tropical Pines

Eight depths of sowing (viz., 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 and 4.0 cm) for three species of pines (viz, Pinus patula, p. caribaea and P. ellioltii) were tried in a randomised block design with four replications in the research nursery of the Forest Research Institute, Dehra Dun (India) to find out the optimum depth of sowing for 'propagation of the pines under Dehra Dun conditions. The results show that 0.5 and 1.0 cm deep sowings gave the highest emergence energy and germination value in case of P. patula and P. caribaea, while in the case or P. elliottii, 1.5 and 2.0 cm deep sowings proved better. 1.0 cm deep sowings gave significantly higher number of seedlings for P. patula as compared to the other depths tried. For P. caribaea also, 1.0 cm deep sowings gave the highest number of seedlings but there was no significant difference between the sowings done at 0.5, 1.0 and 1.5 cm. depths. In case of P. elliottii, 2.0 and 1.5 cm deep sowings gave higher number of seedlings. Based on the overall performance and development of the seedlings In-respect of commencement or germination, total germination germination value, biomass of the seedlings, number of seedlings obtained and survival percent etc., it was concluded that in case of P. patula and P. caribaea. the seed should not be sown deeper than 1.0 cm while for P. elliottii, the sowings should be between 1.5 to 2.0 cm deep.