Comparative evaluation of diploid and tetraploid red clover accessions in a flat area of Northern Bulgaria

Abstract

From the first to third growing season in the field test carried out at the Experimental Station of Soybean (Pavlikeni, Bulgaria) was observed 12 genotypes of red clover, including two Bulgarian diploid varieties Nika 11 (standard) and Sofia 52, four local diploid populations and next six foreign tetraploid varieties, i.e. Kvarta, Astur, Carbo, Elanus, Fregata and Larus. The goal of study was to determine the effect of ploidity level of the varieties as well as the effect of adaptive variability of local populations on fresh mass yield, dry mass yields and their persistence in an agro-ecological area with lower summer moisture assurance for red clover. The highest total dry mass yield was observed for varieties Sofia 52 (2n), Nika 11 (2n), Kvarta (4n) and Astur (4n). The productivity of tetraploids Kvarta and Astur strongly varies depending on the season and the year, as well as the age of sward. According to the obtained comparative production data for cuts and years, the tetraploid germplasm has a stronger adaptation to the limiting moisture. In summer drought, typical for the plains of Northern Bulgaria, tetraploids stop growing and do not compensate for their limited vegetative growth, despite the excellent moisture guarantee in the late summer, as well as in the spring the next growing season. Local wild-type germplasm of the species is characterized by a rapid development and lower yield of fresh and dry forage mass compared to the diploid standard when growing in conditions of optimum moisture but relatively high productivity in the dry conditions of the summer months. The differences in the genotypic productivity response under dry conditions reported in this experiment also suggest that the abiotic limit studied can be successfully responded by the genotype factor.

Specific and Intraspecific P Efficiency of Small-Grain Legumes as Affected by Long-Term P Management

“…Alfalfa has high drought tolerance due to its capacity to utilise soil moisture in deep soil via its deep root system [75,76], but a water deficit after sowing can limit plant growth, when the root system is just beginning to form. Relevant differences between biomass production in both vegetation periods with the doubling of yields from 4 to 10 Mg ha −1 in the seeding year and up to 20 Mg ha −1 in the second year were also measured by the authors of [77][78][79].…”

An innovative approach for the assessment of Bulgarian soybean cultivars

“…The humus horizon is about 40-50 cm. The soil (pH) is neutral with humus content of 3-4%; soil porosity is 47% and quench humidity is 15.2% [15]. The experimental work was performed with Bulgarian soybean cultivars with commercial value.…”

Changes in Agronomic and Forage Nutritive Values of Red Clover in Response to Different Development Stage

“…), tall fescue (Festuca arundinacea Schreb.) and/or perennial ryegrass (Lolium perenne L.) for hay, haylage, silage or grazing (Amdahl et al, 2016;Ergon et al, 2019;Naydenova and Vasileva, 2019;Moloney et al, 2020;Egan et al, 2021). This species is known to cope well in a wide range of soil types, pH levels, and environmental and management conditions (Surmen et al, 2013;Ortega et al, 2014;Chmelikova et al, 2015;Tucak et al, 2019;López Olivari and Ortega Klose, 2020).…”