Design and development of a device for measuring vacuum-pulsation parameters of milking unit

G. ineva1*, V. Vlashev1, . Tsanov2

1 epartment of Agricultural Engineering, Faculty of Agriculture, Trakia University, 6000 Stara agora, Bulgaria 2Technical College ovech, Technical University (Gabrovo), 5500 ovech, Bulgaria

device for measuring the parameters of the milking units was designed and developed. t also provides for the registration of the following parameters: value of the power vacuum, exerted pressure on an artificial teat, the structural components of pulsogram, vacuum value of milking chamber. The data obtained are submitted and saved on a computer with special software.The measuring device is created with four channels and can be used for the diagnosis of milking units irrespective of the milking installation with which they are assembled. The pressure measured in the artificial teat is an indirect indicator of the effects of milking unit on the udder.

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Leaves area characteristics of Betonica bulgarica Degen et Neiĉ. during vegetation

M. Gerdzhikova1*, N. Grozeva2, D. Pavlov1, G. Panayotova1, M. Todorova1

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

Abstract. Survey for establishing the leaves area characteristics of Betonica bulgarica during vegetation was carried out at “Sinite kamani” Natural park, Sliven. Specific parameters per plant as number of leaves; stem leaves length, cm; stem leaves width, cm; stem leaves area, cm2; basal leaves area, cm2; and total leaves area, cm2 were measured on 8 dates during vegetation from 05 April to 05 September. Measurements were performed on indicated plants in different points of four locations as follows: Ablanovo area, 540 m a.s.l. (the area of the population is 1600 m2 and 440 specimens); Upper lift station, 1015 m a.s.l. (the area of the population is 150 m2 and 140 specimens); Microyazovir area, 945 m a.s.l. (the population area is 950 m2 and 95 specimens); Slancheva polyana area 1001 m a.s.l. (the area of the population is 724 m2 and 215 specimens). Total leaves area, basal leaves area and stem leaves area of B. bulgarica were the highest for Ablanovo location. The lowest parameters were measured for the Microyazovir population. Interpopulation variation of the leaves area was lower (4.04% − 32.82%) and higher for intrapopulation variation (67.18% − 95.96%). Number of leaves decreased during vegetation in all locations. Average stem leaves length increased at the beginning of vegetation up to 26 June and decreased up to 05 September. Stem leaves area of B. bulgarica was mainly influenced by the dates during the vegetation period (23.31%) as factor while the total leaves area and basal leaves area were influenced by population as factor. Stem leaves area, number of leaves, stem leaves length and leaves width can be approximately predicted by a regression equation with the days of vegetation as an independent variable.

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Changes in the leaf gas exchange of common winter wheat depending on the date of application of a set of herbicides

Z. Petrova1*, Z. Zlatev2

1Dobrudzha Agricultural Institute, 9520 General Toshevo, Bulgaria
2Department of Plant Physiology, Faculty of Agronomy, Agricultural University, 12 Mendeleev, 4000 Plovdiv, Bulgaria

Abstract. The aim of this investigation was to determine the effect of the date of application of a set of herbicides on the foliar gas exchange of common winter wheat. The investigations were carried out in 2013 and 2014 at Dobrudzha Agricultural Institute (DAI). The following herbicides were used: Derby super VG (33 g/ha), Granstar 75DF (15 g/ha), Lintur 70VG (150 g/ha), Secator ОD (100 ml/ha), Mustang 306.25 СК (800 ml/ha), Palace 75WG+oil (250+1000 g/ml/ha) and Husar Мax ОD (1000 ml/ha) from the group of suflonylureas with various mechanism of action. The preparations were applied at two stages of common winter wheat cultivars Aglika and Enola (stages 29 and 32 according to Zadoks). The indices of leaf gas exchange were followed: rate of net photosynthesis (А), intensity of transpiration (E), stomatal conductivity (gs) and intercellular concentration of СО2 (ci). It was found that the later application (stage 32) of Lintur 70VG and Mustang 306.25СК caused visible signs of phytotoxicity. These were expressed as anthocyanin pigmentation of leaves and spikes and as partial to full sterility of spikes, stronger after using Lintur VG and weaker after Mustang 306.25СК. Following a delayed application of the herbicides, slower rate of growth of plants was observed, as well as disturbances in the parameters of foliar gas exchange. The high rate of A at comparatively low E and gs and the low ci in the weeded check indicated that the plants spent considerable energy resources to overcome the negative effect of weeding.

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Nitrogen mineralization potential of alluvial meadow soil after long-term fertilization

V. Valcheva*, K. Trendafilov, M. Almaliev

Department of Agro-chemistry and Soil Science, Faculty of Agronomy, Agricultural University, 12 Mendeleev, 4000 Plovdiv, Bulgaria

Abstract. The aim of this study was to investigate the nitrogen mineralization potential of alluvial meadow soil after continuous fertilization. Our research was focused on a long-term field experiment with different variants of fertilization set in 1959 in the Experimental field of Agricultural University-Plovdiv. Since 2006 the fertilization has been discontinued. In 2010 and 2011, we collected soil samples from depth 0 – 30cm and from the following variants: 1 – control, 2 – N50P30K20, 3 – N25P15K0 + 6 t/da manure, 4 – N50P0K20. In accordance with relatively high content of total nitrogen, the nitrogen mineralization potential of the soil is high. The maximum amount of nitrogen, susceptible to mineralization at optimum temperature and humidity ranges from 233.21 to 350.90 mg N/kg soil. The proportion of potentially mineralizable nitrogen from the total nitrogen in soil is low – average 17%. The reason for this is the humic type of soil organic matter. Also in its composition dominated black humic acids, which are bonded with Ca and resistant to decomposition. Sufficient amount of clay particles and micropores provide physical protection of organic matter from microbial activity. The mean value of mineralization rate constant (k), 0.041, denotes that at optimal conditions the mineralizable N fraction is released at an average rate of 4,1% per week, based on the quantity of mineralizable N remaining after each succeeding week of incubation.

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Monitoring of fungal diseases of lavender

K. Vasileva*

Department of Phytopathology, Faculty of Plant Protection and Agroecology, Agricultural University, 12 Mendeleev, 4000 Plovdiv, Bulgaria

Abstract. In the period between 2013 and 2014, phytosanitary monitoring was performed to establish the health status of lavender in relation to fungal diseases. During 2013, the diseases spread were investigated on 56.973 ha, and during 2014 – on 218.01 ha, respectively. The calculated disease incidence is 20.84% for the first, and 21.64% for the second year. The data analysis indicates that the phytosanitary situation is very complicated. As a whole, the pathogen infestation on the major varieties at different ages and in different regions was between 3.45% and 53.79%. The percentage of infected plants varies by regions: Karlovo (from 34.08 to 35.65%), Stara Zagora (16.04 – 30.27%), Kazanlak (20.01 – 23.43%), Elhovo (32.67 – 35.10%), Shumen (14.79 – 15.79%). Disease incidenceonthemajorvarietySeuthopolis,in1to3-year-oldlavenderplantationsdiffers:inIganovovillage,Karlovoregionitwas36.18% andinKhanKrum village, Shumen region – 4.73%. This is an indication for the presence of high infection level in lavender fields from the early stages of plant development. It may be due to the usage of infected planting material or to the establishment of new plantations onto old lavender fields. Isolations have been made from different organs of lavender plants affected by pathogens, applying both traditional and specific phytopathological methods. Based on morphological characteristics the following fungi genera have been identified: Phoma (P. lavandulae), Phomopsis (P. lavandulae), Septoria (S. lavandulae), and Phytophthora (P. parasitica and Phytophthora hybrid).

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Effect of stocking density on growth intensity and feed conversion of common carp (Cyprinus caprio L.), reared in a superintensive system

S. Stoyanova*, Y. Staykov

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

Abstract. Optimisation of stocking density of reared fish is one of the essential factors for high yields from aquaproduction. The purpose of the present study was to evaluate the effect of different stocking densities in a superintensive system on growth performance and feed conversion of common carp fingerlings (CyprinuscaprioL.).Fishwithsimilarbodyweight(g)weredistributedinnet cagessized3.0x3.0x2.5m3intoonecontrolgroup(CG)atstockingdensityof 450 individuals/m3 and two experimental groups (CG- 450 individuals/m3; EG1 – 650 individuals/m3 and ЕG2 – 850 individuals/m3), each of them in four replications. The experiment lasted for 60 days. The highest stocking density did not have a negative impact on growth performance of fingerlings and they attained an average body weight of 84.40 g, which was higher than that of fish from CG by 6.36% (p≤ 0.01). Feed conversion ratio of carps decreased proportionally to increasing the stocking density. Specific growth rate showed that it was the lowest in carp fingerlings from the control group – (450 individuals/m3).

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Influence of sowing and fertilization rates on the yield and plant health of einkorn wheat (Triticum Monococcum L.)

V. Maneva*, D. Atanasova, T. Nedelcheva, M. Stoyanova, V. Stoyanova

Institute of Agriculture, 8400 Karnobat, Bulgaria

Abstract. In the period of 2012 – 2014, on the experimental field of the Institute of Agriculture in Karnobat, Bulgaria, was conducted a field trial of various sowing and fertilization rates of einkorn. There were four sowing variants: 100% − optimal sowing rate, accepted as control (420 seeds/m2), 125% (525 seeds/m2), 150% (630 seeds/m2) and 175% (735 seeds/m2). The fertilization rates were also four: unfertilized control − N0, N40, N80 and N120 kg/ha. All the trial variants were investigated for insects, diseases and weeds. The highest einkorn yield was obtained after increasing the sowing rate by 50% above the optimal, followed by 25%. The differences in yield after the various fertilization rates were insignificant, which supported the view that it is not necessary to fertilize einkorn. There is greater lodging of einkorn when the fertilization rate is increased. During the studied period no diseases were found on einkorn. As for the pests, there was found the harmful effect of three types of cereal flies − Phorbia securis T., Chlorops pumilionis Bjerk. and Oscinella frit L. and the cicada Philaenus spumarius. The highest density of 6.5 nb/m2 for the cereal flies was established for the optimal sowing rate and the unfertilized variant, probably due to the sparser crops. During the einkorn spring vegetation period, the cicada Philaenus spumarius was found in its highest density for the optimal sowing rate, probably due to the sparser crops and in the variant with N80 fertilization. The least attacked variants were 175% and N120, due to the greater crop density. With the increase of sowing rate of einkorn the weed density and fresh mass were reduced. The increasing rates of nitrogen fertilization increased the competitiveness of einkorn, which led to reducing the weed density, but the fresh mass per weed plant increased proportionally with increasing the fertilization rates. The weeds in all the trial variants had low density, below the economic threshold of harmfulness.

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Occurrence of grapevine leafroll-associated virus complex in the Republic of Macedonia

E. Kostadinovska*, S. Mitrev, I. Karov

1Department of Plant and Environmental Protection, Faculty of Agriculture, Goce Delcev University, Krste Misirkov, 2000 Stip, Republic of Macedonia

Abstract. Grapevine Leafroll-Associated Virus Complex is caused by several virus species (grapevine leafroll-associated viruses GLRaV -1, -3, -4, -5, -6, -9 and -10) belonging to the genus Ampelovirus, while GLRaV-2 is assigned to the genus Closterovirus. Because of its increasing economic importance, it is criticaltodeterminewhichspeciesofGLRaVare predominantineachregioninMacedoniawherethisdiseaseoccurs.Thelaboratorytestanalysesusedin this study consisted of a combination of two detection methods: serological test (DAS-ELISA) and RT-PCR based testing. The total number of 387 grapevine symptomaticsamplesfrom17regionsincluding27localities,weresurveyedfrom2008to2013. AllofthesesamplesweretestedforGLRaV-1,-2,-3,and-7, byusingBIOREBAandSEDIAGDAS-ELISAkits,andtheresultsshowedthat55.9%(215samples)wereGLRaVpositive. Outofthepositivesamples,69.7% (150 samples) were single infections with GLRaV-3, 15.5% were single infections with GLRaV-1, and 14.8% were mixed infections with GLRaV-3 and GLRaV- 1. Ten representative positive samples were analyzed with reverse-transcriptase polymerase chain reaction (RT-PCR) tests for GLRaV-1, GLRaV-2 and GLRaV-3. This is the first occurrence of Grapevine Leafroll-Associated Virus Complex, including GLRaV-1, GLRaV-2 GLRaV-3 and GLRaV-7 in the Republic of Macedonia.

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Effect of the way of pre-sowing soil tillage for wheat on the development of its roots

P. Yankov*, M. Drumeva, D. Plamenov

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

Abstract. The investigation was carried out during 2008 – 2010 in the trial field of Dobrudzha Agricultural Institute on slightly leached chernozem. To clarify the effect of some ways of pre-sowing soil tillage for wheat on the development of its roots, the following variants of a stationary field trail were analyzed: double disking at depth 10 – 12 cm (check variant); plowing at 20–22 cm + disking; direct sowing – pre-sowing treatment of the area with total herbicides. The development of the roots was followed layer by layer every 10 cm down the 0 – 50 cm soil profile by washing the soil units sized 30х30х10 cm. The soil samples were taken at stages autumn tillering and heading. The root mass was determined under air humidity. At stage autumn tillage of wheat, the root mass per plant was the highest after direct sowing, followed by pre-sowing tillage of soil by disking. At this stage of the crop development the amount of roots per wheat plant was the lowest after plowing. The effect of the applied type of pre-sowing soil tillage for wheat on the distribution of its roots by layers at heading stage was statistically significant at depth up to 30 cm. The relative percent of the roots in the 0 – 10 cm layer according to their net weight was the highest after direct sowing and disking. This value was the lowest after plowing. At depth 10 – 30 cm, the quantitative share of roots under minimal and no-tillage decreased, and under intensive tillage with turning of the soil layer it increased. In the 30 – 50 cm layer, the investigated factor was with the same level of effect on the investigated trait.

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Influence of the farm construction, farm regimen and season on the comfort indices of dairy cows

D. Dimov1*, Ch. Miteva1, Zh. Gergovska2

1Department of Applied Ecology and Animal Hygiene, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria. 2Department of Animal Science – Ruminants and Dairy Farming, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria.

Abstract. The study was conducted at 3 cattle farms within three regions of Southern Bulgaria – Stara Zagora, Haskovo and Plovdiv. At all three farms, rearing of the cows was in free groups with individual rest cubicles in within a semi-open building. The daily regimen was different. At the three farms, the separate technological elements of the cubicles were different with the exception of the neck rail height, which was the same – 120 cm. The cubicle flooring was also different (2.14 m2, 2.31 m2 and 2.37 m2), as well as the bedding usage (straw mixed with composted manure, rubber mat and straw + composted manure). There was a significant influence of the farm and the season on the three comfort indices of cows (cow comfort index (CCI), stall usage index (CUI), stall standing index (SSI)). A significant effect of the hour of measurement was found only in the SUI. The small distance between the front of the cubicle and the neck rail (21 cm), and between the rear of the cubicle and the neck rail (140 cm) led to lower values of CCI (65.46% and 66.37%) and SUI (44.51% and 37.46%), as well as high values of SSI (17.52% and 13.35%). The type of the used bedding also had an influence – these indices had the highest values when the bedding was straw mixed with composted manure, instead of a rubber mat. The larger distance from the neck rail to the front of the cubicle (65 cm), the optimal distance from the neck rail to the rear of the cubicle (150 cm) and a soft bedding of straw mixed with composted manure provided better comfort to the cows, respectively CCI – 78.43%, SUI – 54.34% and SSI – 9.83%. Season had a significant influence on the values of the comfort indices, with lower values of CCI and SUI and higher values of SSI in the summer months, compared to the autumn. The feeding regimen and the milkings number also affected the comfort indices of dairy cows. Their evaluation must be conducted in accordance with the specific farm’s regimen.

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