Ustinova A. Morphological and biological characteristics of the rootstock weed (Sorghum halepense (L.) Pers.) and development of the system for its control in the Steppe in Ukraine

Dissertation for recipience of a degree Candidate of Agricultural Sciences in speciality 06.01.13 - herbology. ? National Agrarian University, Kyiv, 2008.It has been made a careful analysis of current state of the S. halepense in Ukraine. It has been ascertained that ontogenesis of the S. halepense plants in conditions of the South of Ukraine coincides with the phases of organogenesis of plants of the basic agricultural crops that this weed infests. The negative effect of diverse degree of infestation of agricultural crops by plants of the S. halepense on crops' productivity and crop capacity was confirmed. Decreasing of winter wheat's crop capacity made up 1,4 ton per ha, alfalfa hay - 4,8-5,9 ton per ha, grape barries - 4,8-9,4 kg per a bush. So, effectiveness of preparations was following: Panthera, 4% e.c. pesticide (dose 3,5 l per ha) - 97%; Select, 12,5% e.c. (1,4 l per ha) - 96; Targa-Super, 5% e.c. (3,5 l per ha) - 96; Zelec-Super, 12,5% e.c. (2,5 l per ha) - 95%.The developed system of protection of agricultural crops against a mass S. halepense's infestation of fields (as twofold shallow plowing, treatment with herbicide after growing longer of S. halepense plants and deep plowing to 30-32 cm) gives an opportunity to decrease infestation of agricultural crops' fields by the above mentioned weed on 96%. It is 10% more, than carring out the agrotechnical measures only and 12% more, than treatments by herbicides only. At usage of complex system for controlling density of Sorghum halepense (soil treatment+herbicides) the profitability of sunflower growing increases up to 42%.