The effect of temperature and soil moisture on summer survival of two varieties of Phalaris tuberosa

Abstract

The variety Australian Commercial and C.P.I. 19331 of Phalaris tuberosa were grown in two-gallon containers at two plant densities, two shading levels, and two subsoil moisture levels. Shading during the summer reduced soil temperature near the surface by an average of 26°F but had no effect on survival. Percentage survival was highest at low plant density and where moisture was supplied to the subsoil. The Moroccan variety C.P.I. 19331 had a higher survival rate than Australian Commercial under all conditions. The conclusion is drawn that survival depends mainly on the availability of subsoil moisture during the summer.