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Document Type

Research

Keywords

biometeorology; epidemiology; leaf wetness

Abstract

Measurements of dew-period duration by painted, flat-plate, electronic wetness sensors at the top of the plant canopy in a tomato field and on adjacent turfgrass were compared with visual observations. The response range of sensors during the onset of dew sometimes exceeded 5 hr. but was less than 1 hr. on other nights. Sensors in the tomato field indicated dew formation occurred as much as 2 hr. earlier or later than dew became visible on adjacent tomato leaflets at the top of the crop canopy. A calibration threshold for sensors derived from a drying curve resulted in the underestimation of dew-period duration by up to 3.8 hr. and was less accurate than an empirically chosen threshold. Dew duration measured by sensors at the top of the tomato canopy and on adjacent turfgrass deviated from visual observation of dew duration at the top of the tomato canopy by about the same amount of time (0.8-hr. difference). These findings emphasize the need to use properly calibrated sensors for dew-period measurements and to calibrate dew-period measurements in a crop canopy.

Publication Date

June 1994

Journal Title

Journal of the Iowa Academy of Science

Volume

101

Issue

2

First Page

56

Last Page

60

Copyright

© Copyright 1994 by the Iowa Academy of Science, Inc.

Language

EN

File Format

application/pdf