Investigation about the Necrosis Formation “Sharilka” (Aladja) on the Leaves of Field-Grown Tobacco Plants: Part I. About the Causes of the Phenomenon Part II. BiochemicaI Changes in the “Sharilka”-Affected Leaf

A specific dot-like necrosis formation on Oriental type tobacco, called "sharilka'' was studied. The phenomenon is of a physiological nature. It manifests itself under conditions of water excess during the time when the leaves begin to become overripe. It was established that susceptibility to "sharilka" is connected with a low content of pectins and proteins. The latter fact predetermines the lower water binding capacity of protoplasm or higher content of free water in the tissues which suffer from "sharilka''. The raised quantity of free water as a possible source of degenerative cell changes, which become apparent on the leaf in the form of "sharilka", was considered