Volume 7, Number 2, June 2015

Investigation on the technological traits of Bulgarian and imported merino wool batches

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D. Pamukova*

Department of Animal Science – Ruminants and Dairy Farming, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

Abstract. The investigation was performed with industrial batches of merino wool originating from Bulgaria (1), Russia (2), Romania (2), Spain (1) and the Czech Republic (1). A total of 16 batches including 7 greasy wool batches, 5 clean wool batches and 4 wool sliver batches. The primary processing of wool batches (classification, washing and carding) was performed using the standard technologies applied at the textile enterprise. After the classification, the relative proportions of types vs the total amount of greasy wool were determined. Washing yields of classified greasy wool batches were established. Clean merino wool batches were submitted to the following laboratory tests: fibre diameter (μm), mean weighted length (mm), short fibre percentage (%), fatness (%), mineral matter content (%), vegetable matter content (%) and moisture (%). The parameters determined on ready wool slivers were as followed: yield (%), fibre diameter (measured with a lanameter, μm), mean weighted length (mm), length В (mm), short fibre percentage (%) and moisture (%).The two Russian wool batches were superior to all other tested batches with respect to high-grade wool content – 96.88% and 96.03%. They consisted exclusively of a single industrial class – grade 64s merino worsted wool (95.94% and 93.95% of batches, respectively). With regard to the relative share of merino worsted wool, the Bulgarian batch (40.98%) came after the Russian (96.88% and 96.03%), Romanian (batch 1) (90.23%) and Spanish wool (57.85%). Russian wool was superior to other batches with respect to washing yield (55.51%), mean weighted length (55.35 mm) and fibre cleanness (it had the lowest mineral (0.99%) and vegetable matter content (1.2%)). There were no considerable differences with respect to yield, mean weighted length and short fibre percentage between Spanish and batch 1 Romanian wool, although the mineral and vegetable matter percentages were significantly higher in Spanish clean wool. The batch from Czech and Bulgarian wool had higher fibre length, lower dustiness and less vegetable matter content than the Spanish batch, but its washing yield was lower. Compared to both Romanian batches, it occupied an intermediate position. The highest yield was established for slivers produced by Russian and Spanish wool – 80.63% and 80.12%. The yields of the other two batches were substantially lower (72.06% for Romanian and 70.54% for the mixed Bulgarian and Czech batch). The highest mean weighted fibre length was determined for slivers made from Russian wool (67.77 mm) whereas the lowest – for slivers produced from mixed Bulgarian and Czech batch (50.83 mm). The studied Russian wool batches were of greatest interest as their technological properties were concerned. Mixed with Bulgarian wool batches, they could be largely used to correct and improve the yield, short fibre length and proportion in clean wool and wool sliver.

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Near Infrared Spectroscopy and aquaphotomics for monitoring changes during yellow cheese ripening

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S. Atanassova*

Department of Biochemistry, Microbiology and Physics, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

Abstract. The aim of the study has investigation of the feasibility of Near Infrared Spectroscopy (NIRS) and aquaphotomics as a tool for the monitoring a changes during ripening of Bulgarian yellow cheese from cow milk. 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, 15, 20, 25, 30, 35, 40 and 45 days of ripening. Total protein, water- soluble protein, dry matter and titratable acidity were determined for all samples. NIRS measurements were performed by NIRQuest 512 spectrometer (Ocean Optics, Inc.) in the region 900-1700 nm using reflection fiber-optics probe. Aquagram coefficients were calculated. Differences in spectral data of cheese samples in the range of first overtone water region from 1300-1550 nm were found. The changes of aquagram patterns of cheese samples were significant. Investigation of aquagrams showed decreasing the free water and the number of hydrogen bonding of water molecules and increasing of solvated water in the process of ripening. Changes in aquagram patterns depend mainly on changes in titratable acidity and protein fraction in cheese during ripening. We can conclude from obtained results that NIR Spectroscopy and aquaphotomics has a potential for monitoring cheese ripening stage.

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New data about Crocus olivieri Gay on the territory of Sinite Kamani Natural Park, Bulgaria

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N. Grozeva*, M. Todorova2, M. Gerdzhikova2, G. Panayotova2, N. Getova3, D. Dohchev3, K. Tsutsov3

1Department of Biology and Aquaculture, Faculty of Agriculture, Trakia University, 6000 Stara agora, Bulgaria 2Department of Plant Production, Faculty of Agriculture, Trakia University, 6000 Stara agora, Bulgaria
3Sinite Kamani Natural Park, Sliven, Bulgaria

Abstract. e aim of te stud is to estalis te current distriution оf Crocus olivieri in inite amani atural Par to assess te state of its oulations and to define its requirements to soil fertilit. leven oulations of te secies ere reistered ten ne for its territor. t as een estalised tat te secies forms oulations in rass communities dominated esleria latifolia and estuca valesiaca on oen areas and on te outsirts of deciduous forests and uses at an altitude from to m on acid and neutral soils ell stoced it oranic caron and assimilale forms of otassium and less stoced it mineral nitroen and assimilale form of osorus. ts oulations numer from to secimens at an area from to m. ain treats for te oulations of te secies in te atural Par are antrooenic imact indered seed roaation onoin erosion rocesses enetration of Pteridium aquilinum. e status of all oulations is relativel ood ut for teir reservation insitu measures must e alied includin clearin te dead forest and rass mass reseedin in aroriate areas it recollected mature seeds transferrin of vulnerale lants to etter rotected areas of te oulations mecanical control to revent te enetration of Pteridium aquilinum.

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Effect of amitraz on varroosis in bees (Apis mellifera L.)

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K. Gurgulova1, I. Zhelyazkova2*, S. Takova1, K. Malinova3

1National Diagnostic and Research Veterinary Medical Institute, 1000 Sofia, Bulgaria
2Department of Animal Science, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
3Department of Ecology and Landscape Architecture, Faculty of Agriculture, Forestry University, 10 Kliment Ohridsky, 1756 Sofia, Bulgaria

Abstract. In European (Western) honey bee Apis mellifera L. Varroa mites must be continuously monitored to allow colonies to develop normally and realize high productivity and quality of bee products. A clinical trial of veterinary-medical product, based on amitraz, in the form of strips (VMP Apivar ® – 3.33% amitraz) was carried out in the autumn of 2011. High efficiency of the active substance against Varroa destructor in apiaries on the territory of Bulgaria is determined. After exposure of 46 to 78 days high efficiency on varroosis (Varroa destructor) is achieved – average in four apiaries from 99.00% to 99.86%.

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Exploring the yield potential and spike characteristics of Tritordeum (×Tritordeum Ascherson et Graebner) accessions under the conditions of South Dobrudzha

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H. Stoyanov*

Plant Growing Department, Faculty of Marine Sciences and Ecology, Technical University, 1 Studentska, 9010 Varna, Bulgaria

Abstract. For the conditions of Europe the artificially created amphidiploid tritordeum (xTritordeum) could be a promising crop. In order to study its suitability for the conditions of Southern Dobrudzha, Bulgaria, 10 tritordeum accessions were tested for their morphological and physiological characteristics. The winter resistance of plants in two successive crop periods is recorded. The indicators length of spike, length of spike with awns, number of spikelets, weight of spike, weight of grains per spike, number of grains per spike, awness index, number of spikelets along the length of spike, weight distribution along the length of spike, weight of single spikelet, weight of 1000 grains and grain index are reported. The average number of tillers per plant, the time of heading, flowering and full maturity for the economic 2012/2013 is determined. During the same period the attack of pathogens of powdery mildew, brown rust and septoria leaf blight was also recorded. All accessions tested were completely resistant to powdery mildew and septoria leaf blight but susceptible to brown rust. The highest winter resistance in both financial years exhibits accession HT621 (100% survival of plants), and the worst – HTC1324 (40%). Relatively short growing period for accession HT621 was reported, which entered into maturity before the others. With the highest values of yield components (weight of grains per spike, average number of tillers) are HTC1331, HT31-2 and HT119. The accessions with the highest yield potential and the highest winter resistance appear to be promising for future studies on the introduction of the new grain crop into South Dobrudzha.

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Agroecological assessment of wastewater from Municipal Wastewater Treatment Plant by physico-chemical parameters

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G. Kostadinova*, D. Dermendzhieva, G. Petkov, I. Taneva

Department of Applied Ecology and Animal Hygiene, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Вulgaria

Abstract. The purpose of this study was to investigate and assess the wastewater quality in two monitoring points, at input and at output, of Municipal Wastewater Treatment Plant (MWWTP), Stara Zagora, Bulgaria, for a period 2011 – 2014, by physico-chemical parameters (temperature, pH, suspended solids, BOD5, COD, total N and total P), with a view to their discharge into the receiving water body (Bedechka river) and as a resource for irrigation of crops. For sampling and sample preparation of wastewater, international references of ISO and BSS were used. Sample analyses were made by equipment as follows: temperature and pH – BSS 17.1.4.27:1980, by рН-meter Multi HQ440d with integrated temperature sensor; suspended solids – BSS 17.1.4.04:1980; BOD5 – BSS EN 1899-1:2004 and BSS EN 1899-2:2004; COD – ISO 15705:2002 by Spectrophotometer – DR and Thermal reactor-DRB 200; total N and total P by UV/VIS Spectrophotometer and standard cuvette tests of “Hach-Lange” Company, Germany. It was found that: 1) Untreated wastewater (MWWTP input) is characterized by: temperature 7.8oC – 23.0oC, pH 7.47 – 8.41 pH units, suspended solids 46.0 – 167.5 mg/L, BOD 568.4 – 169.3 mg/L, COD 154.4 – 386.5 mg/L, total N 13.0 – 34.6 mg/L and total P 1.95 – 4.40 mg/L; 2) Treated waste water (MWWTP output) is characterized by: temperature 8.2 – 22.3oC, pH 7.24 – 7.40 pH units, suspended solids 1.90 – 35.7 mg/L, BOD5 1.30 – 13.3 mg/L, COD 15.0 mg/L – 34.9 mg/L, total N 2.80 11.6 mg/L and total P 0.60 – 3.67 mg/L; 3) Effectiveness of wastewater treatment by different indicators is as follows: suspended solids 80.5 – 93.6%, BOD5 95.7 – 96.4%, COD 89.0 – 90.8%, total N 64.3% – 74.0% and total P 28.0 – 70.5%; 4) Treated wastewater meets the regulatory requirements for discharge into the receiving water body – Bedechka river by indicators: suspended solids, BOD5, COD, total N and total P (in 2013 and 2014), and deviates from them by content of total N in January 2012 and total P in 2011 and 2012; 5) Treated wastewater meets the regulatory requirements for irrigation of crops by all investigated indices (temperature, pH, suspended solids, BOD5, COD, total N and total P); 6) Despite the high efficiency of the wastewater treatment in MWWTP the problem with nutrients (N, P) is not entirely resolved, which requires improving the technological operation of WWTP and use of suitable additives for their elimination.

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The effect of stocking density on some hydrochemical parameters and growth traits in European perch (Perca fluviatilis L.), cultivated in a recirculation system

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G. Zhelyazkov*

Department of Biology and Aquaculture, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

Abstract. The aim of study is to determine the effect of two stocking densities on some hydrochemical parameters and growth traits in cultivation of perch /Perca fluviatilis L./ in a recirculation system. The fish stocking material consisted of 555 perch (Perca fluviatilis L.) with live weigh of 21.05–28.85 g, that were divided in two groups, each of them with three replications, at a stocking density of SD1 – 137 fish/m3 and SD2 – 94 fish/m3. The fishes are cultivated in concrete tanks with a volume of 0.8 m3 which are part of the recirculation system. They were fed ad libitum three times a day with extruded pellets for trout “Aqua UNI“, a product of “Aqua garant”, with size of the pellets 2 mm. The trial lasted 60 days. The hydrochemical parameters in the recirculation system during the trial were determined through methods adapted for fish breeding. To study the influence of the stocking density on the weight gain and the feed conversion in perch (Perca fluviatilis L.), cultivated in a recirculation system, the average live weight (g) was determined as the fish were individually weighed at the beginning and the end of the trial. During the experimental period the mortality of the perch was also studied as the dead fish were daily controlled. At the end of the trial period the weight gain (g), survival rate (%) and feed conversion ratio (K) of the fish were determined. In the conditions of the experiment we found that the higher stocking density does not evoke changes in most of the hydrochemical parameters of the recirculation system. The only exception is the decreased content of oxygen dissolved in water in SD1 – 7.51±0.12 mg.l-1 compared to SD2 – 8.31±0.13 mg.l-1, as the differences are significant (P<0.05), although its values are within the optimal range of the species cultivated. At the end of the trial a tendency toward higher live weight in the fish from SD2 – 41.82±15.01 g was observed being 4.89% higher than the SD1 fish. The analysis of the data concerning the survival rate shows a trend toward higher value in SD1 – 92.12±4.58%, while in SD2 it is considerably lower – 72.00±20.78%; however no significant difference was found (P>0.05). The weight gain of the perch from the three replicates of SD1 shows that it is 16.18±4.18 g , this being 14.71% lower than that of the specimens of SD2, but the difference was not significant (P>0.05) . The feed conversion ratio of the specimens of SD1 is 1.06±0.04 and it is 17.92% lower than that in the SD2 fish and the difference is significant P<0.05.

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Effect of locomotor activity of Russian sturgeons (Acipenser Gueldenstaedtii Brandt) on water heat flows in a recirculation system

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K. Peychev1*, Y. Staykov2, S. Stoyanova2

1Department of Agricultural Engineering, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria 2Department of Biology and Aquaculture, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

Abstract. The interest and the increasing demand for gourmet fish species is a stable tendency in modern aquaculture. This requires the development of intensive production systems with accurately determined and precisely controlled parameters, providing ecological and sustainable farming of a given aquaculture species The aim of the study was modelling and determination of the effect of swimming speed on heat flows within a recirculation system. An additional analysis of the effect of changing average live weight of farmed Russian sturgeon (Acipenser Gueldenstaedtii Brandt.) on converted heat was made. The experimental tank volume was 70 m3, the diameter – 7.5 m and the depth – 1.6 m. It was situated in a closed thermostable premise, part of recirculation system for Russian sturgeon farming. The water in the tank was exchanged 2.3 times per hour under constant temperature of 22°С. In this tank, about 800 Russian sturgeons (Acipenser Gueldenstaedtii Brandt.), with average live weight of 3.5 kg were reared. The effect of fish swimming speed on the resulting thermal power in a recirculation tank followed the same trend irrespective of the live weight of individuals. The swimming speed of fish in recirculation tanks during the summer months should pertain to the technologically allowable minimum, while during the winter months, fish in recirculation systems should be stimulated to swim at a higher speed close to the maximum technologically permissible limit.

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Influence of fertilization and sowing density on grain production of Sorghum bicolor L., in the climatic conditions of Central Moldavia, Romania

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S. Pochişcanu*, T. Robu, A. Gherasim, M. Zaharia

Department of Plant Science, Faculty of Agriculture, University of Agricultural Sciences and Veterinary Medicine, 3 Mihail Sadoveanu Alley, 700490 Iaşi, Romania

Abstract. Specialists in the USA, European Union, Japan, Australia, China, etc., Investigating industrial exploitation of biomass used in all forms and all adequate technologies. In this context appeared “stars biomass”, of which emerges, first, to the temperate continental sorghum, known and used for many years in the USA, China, Italy and France. Improvement of some technological sequences cultivation of sorghum, is a matter of great importance to our country, in order to obtain high yields, to provide the necessary food, feed raw material in the production of bioethanol, considered a fuel of the future. Experiences has been located in the specific climatic conditions of Secuieni, Central Moldavia, bifactorial type. The biological matherial used were hybrids F32, Armida, Alize, Quebec and KSH2G06. Mineral fertilizers applied to grain sorghum crop, increased grain production. Variation in grain production in grain sorghum varys depending on hybrid and the influence of fertilization. Using higher seeding densities cause significant production increases in grain sorghum, and the production level depends of cultivated hybrid and climatic conditions. The results of this study are part of a doctoral program, funded by the Ministry of Education Youth and Sports research, the IOSUD USAMV Iaşi.

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Tolerance and own tolerance of wheat under conditions of permanent and long-term rotation

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N. Nankov, G. Milev, A. Ivanova, I. Iliev, M. Nankova*

Dobrudzha Agricultural Institute, 9520 General Toshevo, Bulgaria

Abstract. The investigations on the long-term growing of wheat without rotation as well as its two-field rotation with maize in Dobrudzha Agricultural Institute date back to 1957. In a stationary field trial carried out during 2011 – 2013, cultivar Enola was grown at planting density 500 germinating seeds/m2. Four levels of nutrition regime were tested, which were formed by systematic introduction of the following fertilizer norms: N0P0K0, N60P50K30, N120P100K60 and N180P150K90. The long-term growing of wheat in two-field crop rotation increased the productivity of the crop with 16.8 % in comparison to its cultivation without rotation. The yield from cultivar Enola under long-term non-rotation growing was influenced to a much higher degree by the meteorological conditions of the year (1.6 times) as compared to two-field rotation with maize. The systematic mineral fertilization increased wheat productivity under the two forms of rotation. Under two-field crop rotation, the increase of yield according to the non-rotation growing was with 20.9%. Averaged for the investigated period, wheat had higher productivity after mineral fertilization with N120P100K60 (N:P:K=1:0.8:0.5). The intensive nitrogen fertilization, even when preserving the ratio with the other main macro elements, led to lower productivity, especially of the wheat grown without rotation. The factor determining wheat productivity under two-field rotation was mineral fertilization; its strength of effect was 1.9 times higher than its effect on long-term growing without rotation. The meteorological conditions during wheat growing influenced the physical indices of grain, and were especially well expressed on test weight. Under low nutrition regime (the check variant and N60P50K30), the grain in the monoculture was smaller in comparison to the two-field crop rotation. Under the higher levels of fertilization and in the monoculture a tendency was observed toward larger grain. The test weight in both crop rotations decreased with the higher fertilization norms. No significant correlations were found between productivity and the physical properties of grain under both types of growing. Under long-term growing of wheat in two-field rotation, there was a high positive correlation between absolute and test weight of grain.

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