Neues über die elektrische methode zur messung der benetzungsdauer unmittelbar an der pflanze

Abstract In a former publication the author described an electrical method for direct-measurement of the wetness-duration immediately on plants. Meanwhile new types of sensors have been constructed which are suitable for use on broad firm leaves, on small thin leaves, and on stalks and heads of cereals, especially wheat. In addition, an electronic circuit is presented, which issues the information “yes” or “no” according to wetness or dryness of the plant surface. Measurements revealed that wheat-heads are wet, whenever the relative air humidity at a height of 2 m is about 93% or more.