Plant growth of Laelia tenebrosa Rolfe treated with gibberellic acid and grown on different substrates
da Costa Zonetti,Patricia
Bittencourt Guimarães,Ana Tereza
The effect of gibberellic acid (GA3) and different substrates on the growth of Laelia tenebrosa was evaluated. In vitro germinated plants were transplanted to trays, acclimatized, and after nine months used in two experiments: (a) effect of different substrates: coconut powder, Pinus sp. bark, coconut powder + Pinus sp. bark, coconut powder + Pinus sp. bark + charcoal and coconut powder + Pinus sp. bark + charcoal + crushed walnut shells, with five plants/pot and seven repetitions; (b) effect of pulverization with GA3 (0, 25, 50, 100 and 200 mg L-1) with four plants/pot and seven repetitions. After 360 days, the following variables were evaluated: survival rate, shoot height, number of leaves and buds, length and width of leaves and root length. Significant differences were found for number of buds, length of leaves and roots, with the best results for the plants grown in coconut powder + Pinus sp. bark and coconut powder + Pinus sp. bark + charcoal + walnut shells. Significant differences were found with pulverization with GA3 for all variables except for leaf width and the best results were obtained with 25, 50 and 200 mg L-1.