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In 2020 a field experiment was conducted with mutant lines of common bean from M4 generations at the Maritsa Vegetable Crops Research Institute, Plovdiv. The aim of the study was to determine the productivity of plants in drought conditions. Twenty four mutant lines were studied in two variants: optimal (non-treated) and reduced (treated) irrigation regimes. A description of the mutant lines was made according to the following features: color: coloring of the flag; beans - length without beak; bean shape in cross section (through the seed); beans-basic coloring; flowering time. Phenological data were collected for phenophases: budding, flowering, fruit size, consumption and botanical maturity. At consumption maturity, biometric measurements were made of 5 plants per repetition on the following indicators: fresh weight (g) of a plant; number and fresh mass (g) of green beans per plant; length (cm) and width (cm) of beans, total fresh biomass (g). The highest productivity found among the treated plants in consumption maturity were the early mutant lines M 564-193-9-1-1 and 564-193-9-1-2, followed by M 564-190-1-1-1, M 564-110-1-2, and M 564-191-1-1-2, compared to the parent line L 564 and all the rest of early mutant lines. The treated plants developed the phenophases 7-10 days later than those with optimal watering.

The present research study identified garden pea varieties with pronounced tolerance to the allelopatic action of Sorghum halepense. Nine varieties were selected to study the effects of shoot and root weed biomass, applied in three extract concentrations (1, 5 and 10%), on seed germination and initial germ growth. A variance analysis of data revealed significant influence (p <0.05) of three studied factors (variety, type and concentration of extracts) on the investigated parameters. Statistically insignificant was only the influence of extract type (root/aboveground biomass) on seed germination. Based on absolute values of the allelopathic indicator RI, which determines the degree of allelopathic inhibition in terms of germination, germ length and weight in different varieties, the variation was as follows: from -0.30 to -0.04, from -1.31 to -2.96 and from -0.47 to 0.02. The total effect of allelopathic action of S. halepense on all studied parameters, presented as a GGE-biplot analysis, defined Pulpudeva and Puldin varieties as exhibiting higher tolerance, in contrast to Denitsa and Vyatovo, which were sensitive. Ran I, Mira, Musala and Vechernitsa occupied an intermediate position. Cultivation of allelopathic tolerant varieties is a promising addition to the current weed control strategy, especially in organic production.

The field trial was conducted during the growing season 2017-2019 in the experimental fields of the Maritsa Vegetable Crop Institute, Plovdiv, Bulgaria. The study used 10 samples of garden peas (Pisum sativum L). for measurement. Plant tall (?m), height to first fertile node (?m), length of internode (cm), number of tillers, number of branches, number of ineffective nodes, total number of nodes, total number of pods per plant, one pod per fruiting handle, two pods per fruiting handle, pod length (?m), pod width (?m), pod weight per plant, weight of green grains per plant (g), % filled grains, % unfilled grains, average number of grains per pod were assessed. Analysis variance showed significant differences between the genotypes of garden peas in all the traits studied. A lower level of the genetic variance was found compared to the phenotypic one by the number of branches, total number of nodes and one pod per fruiting handle. The coefficient of genetic variation is higher than the phenotypic one for most of the traits and ranged from 5.51-5.82% for pod width and total number of nodes to 56.98-59.09% for number of branches and % unfilled grains. For signs of plant tall (98.32% and 129.31%), height to first fertile node (91.22% and 29.32%), weight of pods per plant (86.83%, 29.32), weight of green grains per plant (83.7%, 11.89%) and % filled grains (77.81% and 24.96%). It was found high inheritance combined with high genetic progress. This is a prerequisite for increasing the biological potential on these traits and a real opportunity to create new forms of garden peas possessing such qualities. The best genotypes were found GEN 1 (22/16-n.), GEN 6 (Marsy-n.), GEN 4 (Plovdiv-n.) and GEN 9 (1/17-n.). They may be used in new breeding programs and hybrid lines may be entered in competitive variety lists.

The purpose of this study was to assess a complex of characteristics of garden pea (Pisum sativum L.) lines grown under organic farming conditions. A field experiment involving three production systems (two organic and conventional) evaluated the productivity, disease and pest infestation and seed quality in four garden pea accessions. The experiment was conducted in the Maritsa Vegetable Crops Research Institute in Plovdiv, Bulgaria during the period 2016-2017. The expression of the studied characteristics in the three production systems was different and was determined by the genetic features of the tested pea lines. Lines 1855 3 and 101i produced a higher average yield of green grain in organic 2 treatment with use of organic fertilization products authorized for organic production and with use of biopesticides for plant protection. Low degree of infestation by Fusarium wilt (Fusarium oxysporum f. sp. pisi), bacterial blight (Pseudomonas syringae pv. pisi), Alternaria blight (Alternaria spp.), downy mildew (Peronospora pisi) and species of pea moths (Laspeyresia spp.) was established in the garden peas grown in different treatments of organic and conventional production. Higher degree of infestation by Ascochyta blight (Ascochita pisi) and higher percentage of seeds, damaged by pea weevil (Bruchus pisi) were established in the organic treatment. The influence of pathogens and pests on the studied lines was limited as a result of application of biohumus and biopesticides. It was found that the seeds from garden pea, grown in the organic treatment had lower absolute seed weight compared to the seeds grown in the conventional treatment. The seed germination was high in the organic production systems for lines 1857 3 and 73 10 .