Possibilities for increasing the yield and quality of asters (Callistephus chinensis L.) cut flower

N. Miteva, O. Tafradziiski
Abstract. Asters (Callistephus chinensis L.) are one of the basic annual sorts for growing in the open with big economic importance for getting cut flower. This is defined not only by their high decorative qualities because of the variety of structure and colouring of the raceme but also by their usage. The aim of the present paper is to study the influence of nitrogen fertilization on the vegetation and generational activities of the plants. Experiments were carried out as field tests. The results show that a higher dosage of nitrogen stimulates plant growth. It has also been established that mineral fertilization has a positive effect on the size of the raceme – larger racemes with bigger tubular discs are formed with many more lingulated petals, defining the fascicularity of the plants.

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Near Infrared Spectroscopy for monitoring changes during yellow cheese ripening

S. Atanassova, N. Naydenova, T. Kolev, T. Iliev, G. Mihaylova
Abstract. . The aim of the study has investigation of the feasibility of Near infrared(NIR) spectroscopy in a diffusion reflection mode as a tool for the monitoring a chemical changes during ripening of Bulgarian yellow cheese from cow milk and classification of cheese according to ripening stage. The cheeses were made according to Bulgarian national standard for Bulgarian yellow cheese from cow milk. Samples for spectroscopic and chemical analysis were taken after 1, 5, 10, 15, 20, 25, 30, 35, 40 and 45 days of ripening. Total protein, water-soluble protein, titratable acidity, dry matter, and sodium chloride content were determined for all samples. NIR measurements were performed by NIRQuest 512 spectrometer (Ocean Optics, Inc.) in the region 900-1700 nm using reflection fiber-optics probe. Partial least square regression with internal cross-validation was used for calibration models development for determination of tested parameters. Soft Independent Modeling of Class Analogy (SIMCA) was implemented to create models of the cheese samples according to maturity stages based on their NIR spectra. Differences in spectral data of cheese samples during ripening were found. The biggest variation in spectral data were observed at 1215, 1350, 1644 nm, region from 1415 to 1470 and 1682-1700 nm. Determination of water-soluble protein, dry matter content and titratableacidity with coefficient of multiple correlation bigger than 0.95 and ratio of standard error of calibration and standard deviation of data set bigger than 3 was excellent. Very good determination was found for maturity rate. Prediction accuracy was good for total protein content and poor for NaCl content of cheese. SIMCA model for discrimination of cheese samples according to ripening stage was developed. We can conclude from obtained results that NIR has a potential for assessing cheese ripening related to changes in the cheese matrix during maturity.

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Fatty acid composition of yogurt supplemented with walnut extract

S. Boycheva, N. Naydenova, G. Mihaylova, T. Dimitrov, D. Pavlov
Abstract. The present study aimed to monitor the changes in fatty acid composition of yogurt supplemented with ground walnut extract and stored over 10 days. Fatty acid content of raw and pasteurized milk, of 24-hour yogurt and 10-day yogurt (stored at 4oC) was assayed. Total saturated fatty acid content of experimental samples of milk was lower while that of unsaturated fatty acids was higher as compared to control milk, 24-hour and 10-day yogurt samples. Assayed fatty acids exhibited higher differences between control and experimental samples with regard to polyunsaturated (С18:2 and С18:3) fatty acids. The total saturated fatty acid content in pasteurized milk with walnut extract decreased by 11.2% compared to raw milk, while remaining unaltered in natural pasteurized milk. Pasteurized milk with walnuts exhibited higher polyunsaturated fatty acid content – 2.6 times vs natural and almost 3 times higher than raw milk. Yogurt containing walnut extract contained by 19.25% more unsaturated fatty acids and by 2.3 times more polyunsaturated fatty acids as compared to natural yogurt. During storage of produced yogurt for 10 days, the amount of С18:3 decreased by 46.8% in the yogurt containing walnut extract and by 34.4% in natural yogurt.

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Effect of the rhizobacterium Bacillus subtilis on the development of the root-knot nematode Meloidogyne arenaria at 378 different temperatures

M. Mohamedova, H. Samaliev
Abstract. Growth room experiment was carried out to investigate the effect of different temperatures on the efficacy of the rhizobacterium Bacillus subtilis on the development of the root-knot nematode Meloidogyne arenaria. Potato plants (Solanum tuberosum L.) were inoculated with M. arenaria second-stage juveniles. At 7th, 14th and 21th days after nematode inoculation the rizosphere of the plants were treated with bacterial suspensions of the two local strains of B. subtilis (A1 and B1). The potato plants were grown in growth room at 16±1, 20±1, 24±1, 28±1 and 32±1ºC. The rate of M. arenaria development in potato roots treated with B. subtilis (strains A1 and B1) was lower than that in the untreated plant roots. The highest efficacy of the bacterium on the development of M. arenaria was observed at 24-32ºC.

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Toxicity of plant protection products towards the imago of Encarsia Formosa Gah

V. Yankova, S. Masheva, B. Boev, K. Toskov
Abstract. The endoparasite Encarsia formosa Gah. is one of the well-known and frequently used bioagents for control of greenhouse whitefly (Trialeurodes vaporariorum Westw.). The effect of many applied pesticides is negative towards this useful species. Successful combination of chemical products and biological method in the integrated plant protection systems requires recognition of their side-effect toward the useful species. Laboratory tests for establishment of the plant protection product toxicity to the imago of the parasite E. formosa were carried out in the Maritsa Vegetable Crops Research Institute, Plovdiv during the period 2007-2011. The products BioNeem Plus 1.5 ЕC 0.25% (i. a. azadirachtin), Preferal WG 0.1% – 0.2% (Paecilomyces fomoso-roseus), Timorex 66 EC 1.0% (i. a. extract from Malaleuca alternifolia), Rubin 72 WP 0.25% (i. a. metalaxil-mancoceb) are non-toxic to E. formosa parasite. These products could be applied in the integrated plant protection systems. The insecticides Bi 58 0.1% (i. a. dimethoat), Confidor energy OD 0.08% (i. a. imidacloprid+deltametrin) and Decis 2.5 ЕC 0.05% (i. a. deltametrin) that are strongly toxic should be avoided in use of the parasite E. formosa.

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Distribution of the black mussel Mytilus galloprovincialis (L.) along the Bulgarian Black Sea coast

E. Petrova, St. Stoykov
Abstract. The authors present data from studies of black mussels (Mytilus galloprovincialis) along the Bulgarian Black Sea coast. There were performed a total of 73 trawls in 6 mussel fields – Balchik, Galata, Byala, Emine, St. Vlas and Cape Maslen. The paper presents the data for size composition of the mussel in the separate fields, the amount yield per unit effort (15 minutes trawling) and the total stock of the fields equal to 92,482 tons. A comparison between different fields shows that the richest field is this in front of cape Emine. As a result of research it was found uneven distribution of the species in fields, as evidenced by fluctuations in the amount yields and the presence of empty trawlers.

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Comparative technical and economic analysis of variants for cleaning and storage of manure on a farm for 108 – 120 dairy 359 cows

V. Dimova, D. Dinev, Y. Popova, Y. Mitev
Abstract. The objective of the study is to develop and explain from a theoretical and analytical point of view suitable and economical design solutions for a farm for 108 – 120 dairy cows with different systems of cleaning and storage of manure and afterwards to prepare a comparative analysis of their most important technological and technical and economic parameters. A total of 2 technological variants for free rearing of cows in a three-line building with end food trail have been compared (one variant for cleaning solid manure by a tractor with a bulldozer shovel and its storage on a site fenced from three sides with reinforced concrete walls and bottom linked through a ditch to a dug-in liquid manure scoop pit and one variant for cleaning liquid manure by a scraper installation and its storage in a reinforced concrete semi-dug lagoon). It has been found out that the variant with a solid manure management system is more economical by relative: built-up area and volume, costs of basic construction materials (concrete, reinforcement and structural steel) and investment costs for constructing the technological profile of the floor of the building, as well as the facilities and equipment for cleaning, transportation and storage of manure. It requires 1,97 times less capital investments (971,30 EUR/stock place) for both constructing and equipping the farm with the variant for liquid manure management (1909,30 EUR/stock place).

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Study on the applicability of a natural geomaterial for mononitrophenol removal from simulated agricultural run-off water

Z. Yaneva, B. Koumanova, N. Georgieva
Abstract. The widespread use of pesticides and herbicides in agricultural areas worldwide has led to serious potential for pollution problems of the soils, surface and groundwaters in the adjacent terrains. The purpose of this study was to evaluate the ability of the geomaterial expanded perlite to remove xenobiotic organic compounds from polluted water introduced by agricultural and other activities. The model compound selected in this study was onitrophenol, a chemical commonly used in the manufacture of pesticides. The experimental equilibrium data were interpreted from Langmuir and Freundlich isotherm models. The applicability of both models was assessed on the basis of the calculated model parameters and correlation coefficients. The statistical significance of the results was tested on the basis of the SSE and RMSE values. The satisfactory efficiency (70 % removal) of the applied method proved its potential for large-scale applications.

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Influence of the farmiing, soil cultivation and Fertilization on the yield of wheat

M. Nankov, L. Glogova
Abstract. Experience was taken for 50years of typical chernozem soil type in the experimental Field of the Maize Research Institute – Kneja. The study take in period 2000-2010 year. The cultivation of wheat in the unit with maize has positive effect on performance mass 1000 grains, hectoliter weight and grain yield. Compared to monoculture wheat grain yield increased with 16, 69%. Deepening of plowing in monoculture wheat has no effect on quantity of grain yield to plowing to 10-12sm (A2). The differences between the test variants are minimal and do not prove mathematically. Fertilization has positive effect on performance mass 1000 grains and grain yield. Compared variants without fertilization, grain yield increases with 1228 kg/ha for A1, 880kg/ha for A2, 953 kg/ha for A3, 804 kg/ha for A4 and 908 kg/ha for A5 and is proved in the mathematical LSD- 0,1%.

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