Four populations of Betonica bulgarica Degen et Neič. at Sinite Kamani Natural Park were morphologically tested. Intrapopulation and interpopulation variabilities were established. The rеlationship between morphological variability, number, area and ecological appurtenance of the studied populations were explored. The results demonstrated that the main source of phenotype variation is intrapopulation variability, mainly due to the age structure of populations. The most variable traits are height of stem and dimensions of leaves. The registered interpopulation variability was affected by the differences in altitude, soil type and differences in environmental conditions and soil properties. Indumentum and morphology of generative organs had taxonomic significance for distinguishing B. bulgarica from the other species in the genus, including the species that were morphologically most similar to it - Betonica officinalis L.

The aim of this study was to establish whether the type of the agricultural system has any influence on the essential oil production and antioxidant activity of industrial cultivated Rosa damascena Mill. in the Rose valley, Bulgaria. Six private farms from Kazanlak (Rose) Valley, Southern Bulgaria were included in the study conducted in the period 2019–2020. The first three selected farms are designated within the conventional farming and the other three are certificated as organic farms. GC/FID and GC/MS analyses were performed; the contents of total polyphenols and flavonoids in the methanol extracts from rose petals were determined. Additionally, the antioxidant activity of rose extracts was evaluated by four reliable methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2´-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS), ferric reducing antioxidant power (FRAP), and cupric reducing antioxidant capacity (CUPRAC) assays. The impact of the agricultural system on the essential oil composition and antioxidant activity was evaluated by ANOVA statistical analysis. The results obtained showed that organic farming produced essential oil with a higher linalool and geraniol content and lower β-citronellol + nerol concentrations than conventional farming. It was found that organic farming production demonstrated a better antioxidant activity evaluated by the three DPPH, ABTS, and CUPRAC methods according to the averaged data for two years, 806.82, 797.66 and 1534.40 mM TE/g dw versus 510.34, 521.94 and 917.48 mM TE/g dw for CF, respectively, with high statistical significance for the DPPH and ABTS analyses. Consequentially, the rose extracts from the organic farming accumulated more phenolic compounds that corresponded to the higher antioxidant potential of the organic roses.

The assessment of aboveground biomass is important for achieving rational usage of pasture resources and for maximizing the quantity and quality of milk and meat production. This study presents a method for fast approximation of pastures' biomass. Unlike most similar studies, which rely on unmanned aerial vehicle and satellite obtained data, this study focuses on photos made by stationary or mobile ground-based visual spectrum camera. The developed methodology uses raster analysis, based on the MGRVI index, in order to classify the pasture into two categories: -grazed‖ and -ungrazed‖. Thereafter, the developed methodology accounts for the perspective in order to obtain the actual area of each class in square meters and in percent. The methodology was applied on an experimental pasture, located near the city of Troyan (Bulgaria). Two images were selected, with the first one representing a mostly ungrazed pasture and the second onea mostly grazed one. Thereafter the images were analyzed using QGIS 3.0 as well as a specially developed software tool. An important advantage of the proposed methodology is that it does not require expensive equipment and technological knowledge, as it relies on commonly available tools, such as the camera of mobile phones.

A field experiment was conducted at Trakia University -Stara Zagora to establish the effect of some growth retardants on morphological and productive parameters in spring pea for grain variety Bogatir. Three combined preparations: Trisalvit (phenylphthalamic acid + chlorocholine chloride + chlorophenoxyacetic acid +salicylic acid) at doses of 300 and 400 сm з *ha -1 ; SM-21 (phenylphthalamic acid + chlorocholine chloride) at doses of 300 and 400 сm з *ha -1 and PNSA-44 (phenylphthalamic acid + naphthaleneacetic acid + chlorophenoxyacetic acid) at doses of 200 and 300 сm з *ha -1 were applied in the early growth phase of the plant up to a height of 15-20 cm. The study showed that the greatest reduction in the stem height (by 12.8% compared to untreated plants) was achieved by applying SM-21 (400 сm з *ha -1 ). The application of growth regulators Trisalvit and SM-21 had no appreciable effect on the production of spring pea grain. Maximum values of yield structure components (number of pods and grain per plant, grain mass per plant and mass of 1000 grain) and the yield were obtained after application of PNSA-44 (300 сm з *ha -1 ) -up to 5.6% (117.2 kg*ha -1 ) more grain than the control. The investigation of the influence of tested factors (retardant, dose and year) demonstrated that the conditions of the year as a factor had the strongest effect on plant height and grain yield.Key Word: spring pea, retardants, height of the stem, yield structure elements, productivity РЕЗЮМЕ В Тракийски университет -гр. Стара Загора е проведен полски опит за установяване ефекта на някои растежни регулатори върху морфологичните и продуктивни показатели при пролетен грах за зърно сорт Богатир. Комбинираните препарати: Трисалвит (фенилфталаминова киселина + 1 837Journal of Central European Agriculture, 2012, 13(4), p.837-849 DOI: 10.5513/JCEA01/13.4.1138 хлорхолинхлорид + феноксиоцетна киселина + салицилова киселина) в дози 300 и 400 с сm з *ha -1 ; СМ-21 (фенилфталаминова киселина + хлорхолинхлорид) в дози 300 и 400 с сm з *ha -1 и ПНСА-44 (фенилфталаминова киселина + нафтилоцетна киселина + хлорфеноксиоцетна киселина) в дози 200 и 300 сm з *ha -1 са приложени във фаза отрастване на растенията (15 -20 cm височина).В резултат на проучването е установено, че най-голямо намаление на височината на стъблото (с 12.76% спрямо нетретираните растения) се постига при прилагане на препарата СМ-21 -400 сm з *ha -1 ). Приложението на растежните регулатори Трисалвит и СМ-21 не влияе съществено върху продуктивността на зърно от пролетен грах. Увеличение на структурните елементи на добива (брой бобове и семена от едно растение, маса на семената от едно растение и маса на 1000 семена) както и на стопанския добив се получава от препарата ПНСА-44 (300 сm з *ha -1 ) -до 5.63% (117.2 kg*ha -1 ) повече зърно. Изследването за установяване влиянието на изпитваните фактори (ретардант, доза и година) показва, че най-силно влияние върху височината на растенията и добива на зърно оказват условията на годината.Ключови думи: пролетен грах, растежни р...

The aim of our study was to compare NDVI index, total nitrogen, chlorophyll and carotenoids content of leaves of oil-bearing roses cultivated under organic and conventional agricultural systems in order to find impact of farm management on the physiology status of Rosa damascena leaves. The experiment was conducted on six private arable areas with Rosa damascena Mill in Rose valley, Southern Bulgaria. The selected study area size was 5000 m2 from each private territory. Three of the oil-bearing rose plantations are certified as organic farming and have been applied an organic agriculture system and the rest of them are characterized as conventional farming. NDVI index of the leaves of Rosa damascena was measured with Plant Pen 310 device in the field. The same leaves were picked up for future laboratory analysis. The total chlorophyll and carotenoids, μg/g dw content of leaves in the 80 % acetone were determined, total nitrogen by Kjeldahl method as well. Linear discriminant analysis (LDA) was performed to classify Rosa damascena leaves on the base of NDVI and photosynthetic pigment content according to relevant farm management. The results from conventional rose bushes leaves contained statistically proven higher total chlorophyll and lower total carotenoids than leaves belonging to organic oil-bearing roses cultivation. It is worthwhile to continue investigations with NDVI leaves measurements as a promising tool for recognition organic or conventional farm production.