RESUMO: Lippia gracilis é uma planta nativa da Caatinga, rica em óleo essencial com atividade antimicrobiana. O trabalho objetivou avaliar o efeito de diferentes tipos de estacas e substratos na propagação vegetativa de L. gracilis . O experimento foi montado em delineamento inteiramente casualizado, em esquema fatorial 3 x 3, sendo 3 tipos de estacas (apical, mediana e basal) e 3 tipos de substratos (areia + húmus, argila + húmus e areia + argila + húmus), com 5 repetições cada. Aos 40 dias foram avaliadas: porcentagem de estacas brotadas e enraizadas, número médio de brotos, comprimento da maior raiz e biomassa seca dos brotos e raízes. Em todas as variáveis as estacas medianas e basais apresentaram melhores resultados do que as apicais. O substrato influenciou apenas na biomassa seca dos brotos, sendo o composto de argila + húmus superior ao areia + argila + húmus e igual, em significância, ao areia+ húmus.

ABSTRACT: Lippia gracilis is a native plant of the Caatinga, it is rich in essential oil with antimicrobial activity. The study aimed to evaluate the effect of different types of cuttings and substrates on vegetative propagation of L. gracilis. The experimental design was completely randomized, in factorial scheme 3 x 3, with 3 types of cuttings (apical, median and basal) and 3 substrates (sand + humus, clay + humus and sand + clay + humus), with 5 replications each. After 40 days were evaluated: percentage of sprouted cuttings and rooted, average number of shoots, length of roots and dry biomass of shoots and roots. In all variables the middle and basal cuttings showed better results than the apical. The substrate influenced only in the dry biomass of shoots. The substrate composed of clay + humus was better than the sand + clay + humus and equal in significance to the sand + humus.

This study evaluated the effect of salt stress on the growth of Lippia gracilis Schauer, a species native to the caatinga (shrublands) of Brazil and rich in essential oils, as well as on the quality of its oil. We exposed individuals of L. gracilis to NaCl, in the following concentrations, for a period of 40 days: 25 mM; 50 mM; 75 mM; and 100 mM. An additional group of plants was not exposed to NaCl (controls). Data were collected on days 20 and 40. We evaluated relative growth rate; shoot and root dry weight; relative water content; proline concentration in leaves; and chemical composition of the essential oil. At all concentrations, NaCl reduced the relative growth rate in comparison with that observed for the controls. No significant difference in relative water content was observed among treatments. In all treatments, the proline concentration in leaves was highest on day 40. Salt stress did not affect the yield or the concentrations of the constituents of the essential oil of L. gracilis, carvacrol and thymol showing the highest concentrations in all treatments.