Effect of pregerminative treatments on Pithecellobium dulce, Leucaena leucocephala and Sesbania spp.

The experiment was made under laboratory conditions with the aim to evaluate the effect of sulphuric acid, boiling water and temperature on speed and percentage of emergence in Pithecellobium dulce (guamuchil), Leucaena leucocephala (guaje), and Sesbania spp (sesbania). Evaluated treatments were: immersion in suphuric acid (90 %), during 15, 30 and 45 minutes; immersion in boiling water; heating stove (70 ºC) and control. In guamuchil, the best percentage of emergence was obtained with sulphuric acid, immersion of 45 and 30 minutes. In guaje, the best percentage of emergence was provoked with immersion in sulphuric acid during 15 minutes. In sesbania, all three treatments of sulphuric acid were statistically equal amongst themselves and different from control. Treatment of immersion under boiling water during five minutes was prejudicial since there was no emergence. Finally, the heating of the seed in stove (70 °C) had no influence in the percentage of emergence of the seeds. Treatments with sulphuric acid obtained the highest velocity of emergence in the three evaluated species