Management of citronella (Cymbopogon winterianus Jowitt ex Bor) for the production of essential oils

Abstract

Citronella (Cymbopogon winterianus) is a plant with repellent properties attributed to the presence of monoterpenes. The essential oils produced by the plant are influenced by agronomic and environmental factors. This work aimed to verify the interference of water stress and mineral nutrition in the development of citronella plants and oil production. Citronella was grown in pots with average capacity of 2.7 kg of soil and induction of water stress for 10 days, and in different doses of nitrogen and phosphate nutrients. The work was carried out in a greenhouse with a completely randomized design and four replications and a 2 × 3 × 2 factorial scheme: two levels of water stress (with and without), three levels of nitrogen (0, 122 and 244 kg ha−1) using urea fertilizer and two levels of phosphate (0 and 300 kg ha−1) using sodium monobasic phosphate. Citronella seedlings were used for planting. The maximum average temperature in the greenhouse was 35 °C. After 90 days of planting, water stress was implanted for 7 days, returning with irrigation after this period. Dry weight of aerial part, roots, number of leaves, photosynthetic rate and production of essential oils were evaluated. The results showed that the nitrogen and phosphate fertilizers intensified the production of the aerial part of the plants. The roots of the plants performed better without water stress and with the application of phosphate fertilizer. The increase in the photosynthetic rate was induced by water stress. The water stress and the use of nitrogen and phosphate fertilizers promoted the increase the essential oils concentration in the aerial part, demonstrating the citronella’s physiological adaptation capacity.