Discussion of “Relation of potential evapotranspiration to environment and kind of plant”

Abstract

The authors cite the need for re‐examination of methods because of inconsistencies and indicate that they have followed Mather's [1951] method of installing and operating modified evapotranspirometers. While it is stated that two plants were grown in each of the corn and celery tanks, no mention is made of tank size or how the number of plants was selected. It is believed that the results would have been quite different had one or three plants been grown in each tank. Suomi [1953] and King and others [1956] have shown that the effective area of an evapotranspirometer cannot be assumed to equal the actual area, even when great care has been exercised with respect to plant density. It was of interest to note that the authors chose to derive solar radiation from black‐minus‐white atmometer values in preference to sunshine duration. Since the correlation analysis (Table 1) indicates that sunshine duration per se is the better index, radiation data derived therefrom [Hamen and others, 1954] would undoubtedly be superior.