The long phenological development of the cereals determines the great variety of factors, which influence the vegetative growth and the formation of their productivity. A priority of the contemporary agricultural practices is the better balance between the agro ecological, biological and technological elements and the higher profitability of production, while limiting the unfavorable effects on the environment. In this relation, breeding is faced with the problem of developing cultivars which can efficiently utilize the nutrients from soil and at a later stage convert them into grain yield. The aim of this investigation was to determine the productivity structure of new genotypes and perspective lines of winter malting barley (Hordeum vulgare L.), developed at Agricultural Institute - Karnobat and Dobrudzha Agricultural Institute - General Toshevo, as well as the correlation between grain yield and its components. The investigation was carried out during cropping seasons 2014 – 2016, which were very different with regard to the combination of meteorological factors. All investigated components of the formed shoot mass, which contributed to the realization of the biological yield potential of the malting barley cultivars, were influenced by the meteorological conditions of the respective year, by the specificity of the cultivar and by their interaction. It was found that the year conditions had determining role for the formation of the biological potential of the leaves, stems, spike and grain. The cultivar had a dominant role for the formation of the number of spikes per ha, the total shoot mass, 1000 kernel weight, the weight of the non-grain part of the spike and its percent from the weight of spike, respectively the weight of grain. By the grain yield formed, all tested materials exceeded the standard Kaskadyor 3. The exceeding varied from 9.02 % in cultivar Yaspis to 52.58 % in line 1015-127. Cultivars Asparuh, Deviniya and Ahat also had high mean productivity, exceeding the standard with 47.56 %, 45. 56% and 41.41%, respectively. High positive correlations were found between grain yield and spike yield, GHI, weight of grain per spike, weight of 1000 grain, NGPS and total mass. The investigated winter malting barley cultivars, regardless of their breeding location, possess high productivity potential and are suitable for growing in the region of Dobrudzha.
Plastic pollution is known to impact the biophysical characteristics of soil. However, there is currently limited knowledge regarding the sequence of events that occur at the foundational levels of terrestrial ecosystems. This encompasses changes in the abiotic properties of soil and their subsequent effects on various aspects of soil-plant interactions, including soil microbial communities and plant characteristics. This study aims to investigate the influence of four different types of plastic pellets - polylactic acid (PLA), polyamide six (PA6), polypropylene (PP), and polystyrene (PS) - on various indicators that reflect soil quality, as well as the growth and development of mangold (Beta vulgaris var. cicla). The study found that the presence of plastic pellets in soil led to significant changes in various parameters, such as the biomass of the plants, the elemental composition of tissues, and root characteristics. The biomass of the plants was reduced in the presence of plastic pellets, indicating that plastic pollution in soil can have a negative impact on plant growth and development. The elemental composition of tissues was found to be altered, which could potentially affect the nutritional quality of the crops. The study revealed changes in root characteristics, which can have implications for nutrient uptake and water absorption.
Soybean (Glycine max L.) production is increasingly threatened by a complex of pathogens, whose occurrence and impact remain insufficiently characterized under Bulgarian field conditions. During the 2020 and 2021 growing seasons, symptomatic soybean plants and soil samples were collected from the Soybean Experimental Station in Pavlikeni, Central Northern Bulgaria for identification of associated pathogens. Isolation and rhizosphere soil baiting assays yielded bacterial, fungal and oomycete isolates, which were identified using molecular sequencing of the ITS regions and comparison with reference sequences in the NCBI GenBank database. The pathogens identified included Phytophthora sojae, Globisporangium ultimum, Alternaria alternata, as well as bacterial pathogen Curtobacterium flaccumfaciens pv. flaccumfaciens. Here we report for the first time the association of C. flaccumfaciens pv. flaccumfaciens with soybean in Bulgaria. Morphological, physiological, and pathogenicity assays confirmed the identity of P. sojae and demonstrated differences in cultivar susceptibility, with cultivar Isidor showing high resistance and Srebrina and Daniela exhibiting high susceptibility. These findings highlight the complex etiology of soybean diseases in Bulgaria and underscore the importance of pathogen monitoring and the use of resistant cultivars as key components of sustainable disease management strategies.
This study was conducted in the experimental field of the Agricultural Protected Environment Center at Sana'a University, during two seasons - 2016 and 2017. The resultant in terms of high production and desirable traits, the continuity of the superior ones for future inclusion in the breeding and improvement programs for this crop, the estimation of some genetic parameters such as the Specific Combining Ability General, the degree of heritability, and the degree of dominance, where in the first season 10 genotypes were cultivated, and inserted into a reciprocal cross-breeding program according to the second Griffing method. The number of genotypes was 55 genotypes. It was randomly distributed to the experimental units with three replications in a randomized complete block design (R.C.B.D). Data related to traits were recorded, plant length (cm) - number of branches, plant -number of leaves, plant - leaf area (cm) - early flowering - number of total flowers, plant - set percentage - average number of fruits, plant - average fruit weight - fruit length (cm) - the diameter of the fruit (cm). It was found that the ratio of variation of the general ability of the coalition to the specific was less than the correct one in the traits plant length - leaf area - early flowering - node ratio - fruit weight - fruit length, which indicates that these traits are the result of the control of genes with a noncumulative effect being more than the result of genes with a cumulative effect, and it exceeded the correct one in the characteristics of the number of branches - the number of leaves - the number of total flowers - the number of fruits - the diameter of the fruit, and this indicates that the cumulative effect of the genes was the largest. The results indicated that the values of the degree of dominance for most traits were less than one, except for the traits of leaf area, early flowering, fruit weight/ (g), and fruit length/cm, which were greater than one, meaning that there were effects of the super-dominant genes.
The purpose of the present study is to present the first data on the net utilization of energy and protein along the feed - sheep milk chain according to newly introduced criteria according to the "Clarcs" system during different control sub-periods of sheep’s milking period. Using adapted for dairy sheep/goats farming methodology for net utilization of energy and protein along the "feed - sheep's milk" chain, “Clarc of energy distribution (CED)” and “Clarc of protein transformation (CPT)” during 3 control periods in the synthetic population "Bulgarian Dairy" were established. The following values were established: CED: 1-st control period (May) – 0.4404 (44.04%); 2-nd (June) – 0.4469 (44.69%); 3-rd – 0.5403 (54.03%). CPT: 1-st control period (May) – 0.2433 (24.33%); 2-nd (June) – 0.2447 (24.47%); 3-rd – 0.2652 (26.52%).
