ABSTRACT

Topping of tobacco (cutting off the floral buds) is cultural practice which guarantees a high economic effect reflected in increased yield and quality. In normal conditions of growing, the topping is accompanied by vigorous formation of suckers. Removal of floral buds and suckers can be performed in two ways: mechanically (by hand or with specialized technique) and chemical (with application of physiologically active substances - FAS). According to the type of their effect on suckers, FAS are divided in those with contact activity and those with systemic activity. So far, from the products with systemic activity the salts (potassium or hallein) of the maleic hydrazide (MH) have been used. After the deadline for its use in Bulgaria has expired, there are no new systemic products to substitute it. The aim of investigation was to study the possibilities for application of the herbicide Glyphosate not only for chemical topping of tobacco plants but also for control of suckers appearing after topping, with high technical and economical effectiveness among parasitic formations, free of phytotoxic effect on the crop.