ISHS Acta Horticulturae 569: I Latin-American Symposium on the Production of Medicinal, Aromatic and Condiments Plants
RESPOSTAS BIOFÍSICAS, ALOCAÇÃO DE BIOMASSA E PRODUÇÃO DE ÓLEO ESSENCIAL DE "PIMENTA LONGA" NO MUNICÍPIO DE IGARAPÉ-AÇU, PA-BRASIL |
| Authors: | E.S.A. Silva, O.G. Rocha Neto, F.J.C. Figueirêdo |
| Keywords: | Piper hispidinervium, stress, photosynthesis, stomatal resistance, safrole |
| Abstract:
- Biophysical Responses, Biomass Allocation and Essential Oil Production of “Pimenta Longa” at Igarapé-açu, PA - Brazil Between May/98 and March/99, net photosynthesis (NP), stomatal resistance (SR), leaf water potential (  L), biomass allocation and safrole production were evaluated in Piper hispidinervium. It was also evaluated the local rainfall, the photosynthetically active radiation and the relative humidity.
The treatments were: T1 - irrigated and non-fertilized; T2 - irrigated; T3 - non-irrigated and non-fertilized; T4 - non-irrigated and fertilized.
Starting from the 6th day without the rainfall, alterations were observed on the studied variables.
In the 15th day of water stress, in the treatments without irrigation, it was observed the largest impact on the variables, where the pre-dawn water potential was reduced from -0.05 MPa to -0,5 MPa, the stomatal resistance increased from approximately 0.3 s.cm-1 to more than 5.0 s.cm-1, at 9:00h a.m, and net photosynthesis was reduced from 20 mmol.m-2.s-1, to around 1.4 mmol.m-2.s-1. After the periods of deficits, the plants recovered capacity, displaying values close to the ones observed in the plants without water stress.
Biomass and essential oil productions were reduced by 50%, compared to the irrigated and fertilized treatments, until the 7th month after planting, when changes in the biomass allocation pattern were noticed in the irrigated treatments.
In the 9th month, with the re-establishment of the rainfall, recovery of plant growth was observed in the non-irrigated treatment.
Thus, water deficiency in any phase of the plant development, affects the production of essential oil.
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