Soil Redox Potential and Citrus Leaf Stomatal Conductance as Affected by Flooding and Root Weevil Feeding.
(S03-li117352-poster)
Authors:
H. Li* - University of Florida J. Syvertsen - University of Florida C. McCoy - University of Florida A. Schumann - University of Florida
Abstract:
A greenhouse study was conducted to determine the effects of flooding durations on soil redox potential, and to compare the interaction of flooding and larval root weevil (Diaprepes abbreviatus (L.)) feeding on citrus leaf stomatal conductance and root damage. The treatments consisted of two rootstocks, Swingle citrumelo (SWI) and Smooth Flat Seville (SFS), four flooding durations (0, 10, 20, and 30 days), and larval feeding for 42 days, arranged in a completely randomized design. After
flooding five larvae per seedling were introduced onto the soils. Flooding significantly reduced soil redox potential, and flooding, rootstock variety, and their interaction significantly affected leaf stomatal
conductance. Soil redox potential dropped from +200mV to below -100 mV within 1-3 days of flooding. After 30 days of flooding leaf stomatal conductance was only 25% of the initial values.
Swingle was more tolerant of water stress by flooding than SFS. Survival of DRW larvae was higher in flooded treatments than the non-flooded control. Flood damaged plants were more susceptible to root injury by larval feeding than non-flooded plants. We conclude that a negative soil redox potential and a decrease of leaf stomatal conductance might be useful as early indicators of plant water stress from flooding and root damage from weevil larvae.
Speaker Information: Hong Li, University of Florida, Citrus Research and Education Center700 Exprimen, Lake Alfred, FL 33850; Phone: 956-863-1151; E-mail: [email protected]
Session Information: Wednesday, November 5, 2003, 4:00 PM-6:00 PM Presentation Start: 4:00 PM (Poster Board Number: 1134)
Keywords: Soil flooding duration; Soil redox; Citrus leaf stomatal conducta; Diaprepes root weevil pressure