Agriculture Reference
In-Depth Information
2.1 INTRODUCTION
Creation of highly productive, genetically valuable forms with high competitiveness
in ecosystems of mountain hayfields and pastures is an important element of fodder
base formation in the North Caucasian region. Existing in the region, clover cultivars
of hayfield-pasture type have low productive longevity, and this fact creates substan-
tial hardships for the formation of agrocenoses in mountain and foothill conditions.
The main obstacle in the way of growth of the biological potential of this species is the
low adaptive capacity of recommended cultivars in conditions of vertical zoning. The
specifics of environmental conditions in mountain regions with billowy relief, where
more than half of all agricultural lands are situated in complex topographic conditions
characterized by changes of soil-climatic gradients and demands the use of stress-
tolerant cultivars. Highly productive cultivars and hybrids are usually less tolerant to
such conditions, less effective in conditions of undersow due to low competitiveness
with native species, and they have low survival rate of sprouts. Individuals, which
have survived, do not live for long and soon fall out the grass. In practice, this leads to
unjustified costs of labor and funds [1]. Evaluation and use of genetic potential of lo-
cal wild populations of red clover has a special importance due to their specific stress
tolerance.
Wild mountain species of clover are known for their longevity, frost hardiness, and
high content of nutrients. They are more tolerant to high levels of ultraviolet radiation.
These species are highly competitive in phytocenosis of mountain hayfi elds and pas-
tures, and they have a larger number of leaves and shoots per plant. But one should not
ignore the rich genetic material of the existing clover cultivars from other regions with
wide number of undoubted merits such as high productivity and quality. However, it is
necessary to take into consideration that geographic and climatic differences demand
the thorough study of introduced forms in conditions of any defi nite region [2].
Segregation of initial samples for selection is impossible without elaborate bio-
chemical evaluation with the establishment of rate of infl uence on the parameters un-
der study of the complex of factors affecting plant organism, including stages of devel-
opment [3]. With the knowledge of amplitude of variation of chemical trait within the
limits of population difference, it is possible to choose initial forms for hybridization
[1, 4].
In connection with this, the aim of our research consisted in the study of economic
and biological traits of introduced forms of the red clover and in selection of samples
promising for creation of hayfi eld-pasture cultivars in North Ossetia—Alania.
2.2 MATERIALS AND METHODOLOGY
We have completed the study and selection of red clover cultivars, introduced from
different ecological-geographic natural habitats. Productivity and biochemical con-
tent were determined among Belarussian introduced cultivars and samples of red
clover (Minskiy Mutant, Ustodlivy, Yaskravy, SL-38, T-46), an introduced cultivar
from Siberian region (SibNIIK-10) as well as native wild forms growing in conditions
of vertical zoning in North Ossetia—Alania: Dargavski (1,800 m above sea level)
and Gornaya Saniba (1,200 m above sea level). Parameters of economic and biologi-
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