Abstract
Recently so called "Kareure" phenomenon of barley plants in which the plants mature too early and die, has been rather widely observed on fields in warm and dry region of western Japan. An extremely marked symptom appears in ears. This phenomenon has been observed to occur seriously in years with dry and warm maturity season, and on soils deficient in potassium, and sometimes in magnesium etc. The writers studied the phenomenon and recognized a degeneration in the roots of "Kareure" plants. The degeneration was as follows;- After heading, especially in milky maturity stage, the root which had grown quite normal up to that time showed discoloration in the root stele which was due to the filling with yellowish brown substances in the pareachyma and vessels. In a few cases, the similar degeneration was also observed in internodes of stems near the ground. The degeneration was proved to be controlled almost by an application of potassium and magnesium which is deficient in the soil.
