The objective of this work was to optimize the seedling emergence and development of Trifoliata citrus rootstock [Poncirus trifoliata (L.) Raf.] by means of mechanical treatments of the seedcoat and variations in the sowing depth. The experiment was carried out in June-October of 2004, in a glasshouse with controlled temperature. The sowing was carried out in dibble tubes, with commercial substrate. Integral seedcoat, seedcoat with one orifice in the endosperm at the opposite side of the embryo and without seedcoat and four sowing depths (0.5; 1.0; 2.0; and 3.0 cm) were the treatments tested in a randomized complete block design, with two factorials and four replications. The experimental unit consisted of 48 dibble tubes with one seed each. The removal of the seedcoat propitiated higher final germination percentage (90%), in relation to one orifice in the endosperm (83%) and to the maintenance of the seedcoat (73%). The development of the rootstocks was greater with the use of seeds without seedcoat or with one orifice in the endosperm. The sowing depth of 1 and 2 cm is recommended for Trifoliata rootstock.
Poncirus trifoliata; germination; seedling emergency; dormancy break
