Abstract
The laboratory and field performance of two electrical resistance (ER) sensors of leaf surface wetness were compared with that of a beta-ray gauge (BRG). The BRG provided the most accurate measurements of wetness duration, which were in agreement with visual observations. A Campbell and a cotton cloth ER sensor consistently underestimated the duration of leaf surface wetness compared to the value obtained with the BRG in a dew chamber. However, the response of the Campbell sensor improved considerably with increase in the severity of dewfall. A superior performance of one of the two ER sensors could not be decisively established on the basis of the field experiments of 1989 and 1990 on soybean and tobacco crops, respectively. For studies where accurate measurements of surface wetness are critical, it is suggested that a beta-ray gauge should be used.
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References
Baier W (1966) Studies on dew formation under semi-arid conditions. Agric Meteorol 3:103–112
Barthakur NN (1985) A comparative study of radiometric and electronic leaf wetness sensors. Agric For Meteorol 36:83–90
Barthakur NN (1987) Comparisons of beta-ray and electronic leaf wetness sensors in a dew chamber. Int J Biometeorol 31:57–63
Bunnenberg C, Kuhn W (1977) Applications of the beta-absorption method to measure dew on soil and plant surfaces. Int J Appl Radiat Isot 28:751–754
DeWeille GA (1965) The epidemiology of plant disease as considered within the scope of agrometeorology. Agric Meteorol 2:1–15
Duvdevani S (1964) Dew in Israel and its effect on plants. Soil Sci 98:14–21
Getz RR (1978) Dew-monitoring network in the southeast. Bull Meteorol Soc 59:1150–1154
Getz RR (1981) The determination of wetting duration in plant canopies. Fifth Conference on Micrometeorology and Agricricultural and Forest Meteorology, Anaheim, California, pp 155–157
Gillespie TJ, Kidd GE (1978) Sensing duration of leaf moisture retention using electrical impedance grids. Can J Plant Sci 58:179–187
Huband NDS, Butler DR (1984) A comparison of wetness sensors for use with computer or microprocessor systems designed for disease forecasting. Proc Br Crop Prot Conf 2:633–638
Monteith JL (1957) Dew Q J R Meteorol Soc 83:322–341
National Oceanic and Atmospheric Administration (NOAA) (1971) Federal plan for a national agricultural weather service. US Government Printing Office, Washington DC, Report no 13
Pedro MJ Jr, Gillespie TJ (1982) Estimating dew duration. I. Utilizing micrometeorological data. Agric Meteorol 25:283–296
Phillips DV (1984) Stability ofMicrosphaera diffusa and the effect of powdery mildew on yield of soybean. Plant Disease 68:953–956
Smith CA, Gilpatrick JD (1980) Geneva leaf wetness detector. Plant Disease 64:286–288
Wallin JR (1963) Dew, its significance and measurement in phytopathology. Phytopathology 53:1210–1216
Weiss A, Hagen AF (1983) Further experiments on the measurement of leaf wetness. Agric Meteorol 29:207–212
Weiss A, Lukens DL (1981) Electronic circuit for detecting leaf wetness and comparison of two sensors. Plant Disease 65:41–43
Weiss A, Lukens DL, Norman JM, Steadman JR (1989) Leaf wetness in dry beans under semi-arid conditions. Agric For Meteorol 48:149–162
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Armstrong, R., Barthakur, N.N. & Norris, E. A comparative study of three leaf wetness sensors. Int J Biometeorol 37, 7–10 (1993). https://doi.org/10.1007/BF01212760
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DOI: https://doi.org/10.1007/BF01212760