Agrobiological Characteristics of Aftermath Ability and Shoot Structure in Cultivation of Fodder Sorghum

The article presents long-term results of the study of the aftergrowth mechanism depending on the morphobiological parameters of the structure and development of fodder sorghum plants, the time of cutting, cutting height, application of mineral fertilizers and other technologies of sorghum crops cultivation. The aim of the research was to study the agrobiological characteristics of aftergrowth and the shoot structure of crops of sugar sorghum, Sudan grass and sorghum-Sudan hybrids in conditions of gray forest soils of the south-western part of the Central region of Russia (Bryansk region). Research methods include field, laboratory and statistical methods. Four types of aftergrowth have been identified: ۱) - formation of new shoots from the buds of the tillering node (mesocorm); ۲) - formation of new shoots from the uncut first (lower) internodes in the leaf axils; ۳) - growth of shoots whose apical point was untouched during cutting (from uncut short shoots); ۴) - from the meristem tissue of cut shoots through their reproduction. According to the aftergrowth ability, a group of grass sorghum with good aftermathability and sugar sorghum with slight aftergrowth of the shoots can be singled out. The magnitude and differences in the aftermath yields are associated with the phytomeric structure of the sorghum plant shoots that grow and develop their primordia due to the activity of the apical meristem. Prevalent in the pastures of the studied genotypes of sorghum were generative, elongated vegetative and lateral aerial shoots with a complete and incomplete development cycle. The formation of a greater number of lateral aerial shoots (with branching) and shortened shoots was observed in plants on fertilized variants, especially those treated with nitrogen supplements. Prevalent in the aftergrass pastures of Sudan grass and a sorghum-Sudan hybrid were elongated vegetative shoots with a high proportion of leaves from ۴۵ to ۵۷%. When cut at۱۰–۱۲ cm, a more intense aftergrowth of grass sorghum was observed. The yield of the aftermath of the sorghum and sorghum-Sudan hybrid was on average ۱۴.۳–۲۲.۷% higher than by a low cut (۵–۶ cm). The maximum yield of dry matter of more than ۱۵.۰ t/ha was obtained using the aftermath of Sudan grass.

Keywords:

Fodder sorghum , Phytomer , Mineral fertilizers , Cutting height , Aftermath