Impact of weather conditions and sowing method on seed performance of meadow clover in the Middle Urals

Abstract

Seed production of perennial leguminous herbs, including meadow clover (Trifolium praténse), is complicated due to the natural and climatic conditions of the region. In Middle Urals, only two to three years out of ten are favorable for seed production. Estimation of influence of the hydrothermal regime of the growing season and the sowing method has been carried out in the experimental crop rotation of the Udmurt Research Institute of Agriculture, UdmFRC Ural Branch of the RAS with the seed grass stand of meadow diploid clover varieties Pelican and Trio, tetraploid variety Kudesnik It has been revealed that seed productivity of meadow clover on sod-podzolic medium loamy soil was more dependent on the prevailing hydrothermal regimes of vegetation periods, as well as on the variety’s ploidy. A relatively high seeds yield of the Pelican variety (2n) 444-593 kg/ha and Kudesnik variety (4n) 101-116 kg/ha was formed under conditions of insufficient and optimal moisture supply of the vegetation period with a hydrothermal coefficient of 0.67-1.41. With increase in hydrothermal coefficient p to 1.56-1.69, the seeds yield of the Trio variety (2n) decreased to 251-328 kg/ha, of the Kudesnik variety (4n) - to 77-91 kg/ha. Under the same conditions, according to the hydrothermal regime of vegetation, the Kudesnik clover variety formed a relatively larger number of stems and heads, however, the heads productivity was significantly inferior to diploid varieties, which ultimately affected its seed productivity. Sowing diploid varieties of meadow clover Pelican and Trio in the usual ordinary way (15 cm), tetraploid variety Kudesnik in a wide-row way (30 cm) allowed increasing seeds yield and thereby neutralizing the negative impact of weather factors. Sstudy of the seed formation features of meadow clover varieties differing in ploidy in contrasting agrometeorological conditions may be of interest in developing methods for optimizing their seed productivity.