Geneva Leaf-Wetness Detector. C. A. Smith, Research Support Specialist, Department of Plant Pathology, New York State Agricultural Experiment Station, Cornell University, Geneva, NY 14456. J. D. Gilpatrick, Associate Professor, Department of Plant Pathology, New York State Agricultural Experiment Station, Cornell University, Geneva, NY 14456. Plant Dis. 64:286-288. Accepted for publication 22 October 1979. Copyright 1980 American Phytopathological Society. DOI: 10.1094/PD-64-286.

An electronic instrument that measures the incidence and duration of leaf wetness, ie, free water on leaf surfaces, needs only a low power supply and may also be used to activate other devices, such as spore traps. Leaf wetness can be recorded on a modified weather-recording instrument, such as a hygrothermograph, or used on-line in a disease-forecasting computer program. The Geneva instrument compared favorably with the deWit detector in measuring leaf wetness in apple orchards and bean fields.