Open AccessUso da subirrigação para imposição de estresse hídrico em sistema semi-contínuo para medição de CO2
Author(s) -
Rhuanito Soranz Ferrarezi,
Marc W. van Iersel,
Roberto Testezlaf
Publication year - 2015
Publication title -
ornamental horticulture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.274
H-Index - 6
ISSN - 2447-536X
DOI - 10.14295/aohl.v21i2.699
Subject(s) - water content , irrigation , shoot , environmental science , moisture , horticulture , agronomy , chemistry , biology , geotechnical engineering , organic chemistry , engineering
The objectives of this work were to evaluate the effects of distinct moisture contents to trigger subirrigation on salvia photosynthesis and plant growth, and to verify the feasibility of subirrigation use in water stress imposition research in this crop. We evaluated two substrate volumetric water contents (VWC) as treatments (0.2 and 0.4 m3 m-3) to trigger subirrigation, with 4 replications. Each replication was composed of 10 plants. An automated semi-continuous multi-chamber crop CO2-exchange system was used, with capacitance soil moisture sensors for continuous moisture monitoring. Manual subirrigation with nutrient solution was performed when VWC dropped below the thresholds. In both treatments, the values of net photosynthesis, daily carbon gain and carbon use efficiency reduced over time, from 2 to 1.1 μmol s-1 from 2.2 to 1 μmol d-1 from 0.7 to 0.45 mol mol-1, respectively, in both soil moisture treatments. Total shoot dry mass (p=0.0129), shoot height in the tip of the highest flower (p<0.0001) and total leaf area (p=0.0007) were statistically higher at 0.4 m3 m-3 treatment. The subirrigation system was not efficient to impose water stress, due to excessive variation on VWC values after each irrigation event in both treatments. Higher soil moisture promoted positive plant growth responses in salvia cultivated by subirrigation.