Sérgio Horta Mattos

Características do óleo essencial de capim-citronela em função de espaçamento, altura e época de corte

Citronella grass (Cymbopogon winterianum Jowitt.) has grown in importance due to an increasing demand of the essential oil. The influence of spacing (50 x 50; 50 x 80 e 80 x 80 cm), cutting height (15 and 30 cm above ground) and harvesting season (four, six and eight months after planting) on productivity and essential oil quality was evaluated. The study. occurred in field, in Pentecoste, Ceara State, Brazil, from September 2002 to September 2003. The treatments were organized in a factorial 3 x 3 x 2 scheme, in randomized block design, with three replicates. Cutting plants four months after planting date resulted in significantly higher essential oil production when cut at 30 cm height. Six months after planting date, higher yield was obtained at 15 cm height. The cutting height did not influence essential oil production when plants were harvested after eight months. Using larger plant spacing (80 x 80 cm) resulted in significantly higher essential oil production when plants were cut at 15 cm, divergent to the result observed with minor spacing (50 x 50 cm). The citronellol + citronellal content was significantly higher in plants cultivated at intermediate spacing and cut after six months at a height of 30 cm. The geraniol content, however, was higher in plants harvested after four months, with no influence of spacing or cutting height.

Influência de diferentes composições de substratos na propagação vegetativa de Gypsophila no litoral cearense

The species Gypsophila paniculata L., popularly known as babys breath, branquinha or mosquitinho, belongs to the Caryophyllaceae family and has been grown commercially for sale as a cut flower. Its propagation is by means of rooted cuttings. The objective of this study was to evaluate coir dust and charred rice husks as substrates, both separate and in mixture, with an aim to the good rooting of Gypsophila paniculata cuttings. The work was caried out at the Fazenda Plurinvest Agropecuaria e Turismo Ltda farm, located in Trairi, Ceara. The experimental design was completely randomized, with eight treatments and four replications (of 10 cuttings each). The treatments were: coir dust; solarised coir dust; coir dust treated with fungicide (Propamocarbe); solarised coir dust treated with fungicide; charred rice husks; charred rice husks treated with fungicide; charred rice husks and solarised coir dust; charred rice husks and solarised coir dust, the mixture treated with fungicide. After 24 days in a greenhouse in 50% shade and under irrigation by misting, the root dry-matter (g), longest root length (cm) and shoot length (cm) were evaluated. For the root dry-matter, root length and shoot length variables, the substrates of charred rice husks (0.099 g, 5.50 cm and 6.2 cm respectively) and charred rice husks with solarised coir dust (0.097 g, 5.40 cm and 6.1 cm respectively) gave the best results for the vegatative propagation of Gypsophila paniculata.