A simple method to assess the relative amount of leaf wetness in rice canopies

摘要

Leaf wetness is a critical factor in the development of many diseases. Leaf wetness in the plant canopy may come from dew, guttation, rain, or irrigation. Leaf wetness in rice crops is influenced by canopy structure (leaf area, density, and angle), which is, in turn, affected by plant development stage and cropping practices, including planting density. Leaf wetness measurement is possible using sophisticated — and often expensive — mechanical or electronic leaf wetness sensors or recorders. In many cases, several sensors must be used to address the vertical structure of the canopy and its successive layers.