Soil and Diaprepes Root Weevil Biological Zoning in a Poorly Drained Citrus Grove. (S03-li505506-oral)
Authors:
H. Li* - University of Florida J. Syvertsen - University of Florida A. Schumann - University of Florida C.W. McCoy - University of Florida R.J. Stuart - University of Florida B. Castle - University of Florida
Abstract:
Diaprepes root weevil (DRW) management requires an understanding of soil property variation in space and time. A study was conducted in a poorly drained citrus grove of ‘Hamlin’ orange on Swingle
citrumelo (Citrus sinensis L Osb. x Poncirus trifoliate L.) rootstock in center Florida starting in 2002.
The objectives were to assess spatial variability of DRW in relation to soil characteristics, and to determine soil-DRW management zones. Soil electrical conductivity (EC) was measured using EM38 throughout the grove. Diaprepes adult populations were monitored using Tedders traps placed in a 35 x 25 m grid across the grove, and soil organic matter, pH, P, K, Ca, Mg, and other properties were measured at each Tedders trap. Peaks of DRW adults were measured in the south-western field, and DRW appeared significantly more in June. Three biological zones for DRW were delineated based on the spatial patterns of soil EC, and correlations between EC and DRW were significant within zones. In entire field Diaprepes frequency was significantly high in areas low in Mg and Ca. Semivariogram for DRW, Mg and Ca ranged within 100-175 m, which was matched with the DRW biological zone limits.
The results suggest that soil and DRW population correlations can be better described using biological zoning, and DRW management could be related to soil liming practice.
Speaker Information: Hong Li, University of Florida, Citrus Research and Education Center700 Exprimen, Lake Alfred, FL 33850; Phone: 863-956-1151; E-mail: [email protected]
Session Information: Monday, November 3, 2003, 8:25 AM-11:00 AM Presentation Start: 10:30 AM
Keywords: Soil EC; Diaprepes root weevil; Biological zoning; Principal component analysis