Influence of the disk angle adjustment on the condition soil surface using surface tilling machine

M. Dallev, I. Ivanov

Abstract: The modern soil treatment theory is based on the great variety of soil and climate conditions, the rapid development of the equipment and on the application of chemicals in agriculture. One of the main conditions for efficiency of the soil treatment system is the application of a differentiated agroenvironmental approach and innovative technologies in every region. The purpose of this study is to determine the effect of the angle of adjustment of the implement of a surface tilling machine on the field surface.


Sensory and nutritive quality of fermented dry sausages produced in industrial conditions

A. Kuzelov, O. Savinok, T. Angelkova, M. Mladenov

Abstract. The paper investigates the sensory and nutritional quality of two groups of dry sausage produced in industrial conditions. The first group was produced with the addition of the nitrite salt and glucono delta lactone (GDL) and fibbers and another group with the addition of nitrite salt starter culture. Analysis of the results obtained in this study it was found that better quality sensory had tea sausage produced with the addition of a GDL. As for the quality nutritive no statistically significant differences with both groups of sausages.


Changes in the chemical composition of some pieces of pork stored at different temperatures

A. Kuzelov, O. Savinok, T. Angelkova, Dijana Naseva

Abstract. The paper includes changes that occur in vacuum packed pieces of meat obtained by removing the haunch, vacuum packed and kept in a chamber at different temperature conditions of 4ºC. and 6ºC. The changes that occur during storage were examined at 2, 3 and 5 days after production. It was found that during the storage of meat cuts, there are significant changes to reduce water content, while protein, fat and mineral substances are increasing. The total number of bacteria in meat cuts during storage is increased in those who are kept at a temperature of 6ºC. During storage of meat cuts from production to 3 days best sensory characteristics of meat cuts have that meat cut that has been stored at 4ºC.


Acute toxicity of benzoates for different species

Y. Koleva

Abstract. With the development of synthetic chemistry, combinatorial chemistry and pharmaceutical chemistry, millions of new compounds are being synthesized. Classical chemical substance evaluation needs a lot of time and is expensive, and the speed of analyzing the toxicity of compounds is less than the speed of discovery of new compounds. Quantitative structure-activity relationships (QSARs) have been efficiently used for the study of toxicity mechanism of various compounds. All organic chemicals have the potential to cause narcosis. Their ability to do so is mainly governed by their concentration and their ability to cause more serious toxic effects, which would mask any narcotic effect the chemical may cause. Esters possess physicochemical properties of nonpolar narcotics such as nonreactivity and low water solubility associated with low polarity. The aim of this study was to research and compare the acute  toxicity of benzoates for different species (aquatic and terrestrial).


Monitoring of pest populations – an important element of integrated pest management of field crops

V. Arnaudov, S. Raykov, R. Davidova, H. Hristov, V. Vasilev, P. Petkov

Abstract. The population dynamics of several economically important field crop pests and some specialized pests in sugar beet on chernozem soil in the Northeast of Bulgaria (Shumen Region) was studied in the period 2009–2010. Insect survey was carried out to establish the population density of pests in wheat fields (as a preceding crop) and in sugar beet crops. Pest density ranged from 1.7 to 5.8 larvae/m2 for Elateridae family, from 0.2 to 3.6 larvae/m2 for Scarabaeidae, from 0.4 to 7.2 beetles/m2 for Bothynoderes punctiventris Germ., from 0.1 to 21.5 caterpillars/m2 for Mamestra spp. and from 0.1 to 5.7 caterpillars per plant for Gnorimoschema ocellatella Boyd, respectively. The observations of the population dynamics of pests provides the opportunity to implement efficient and economically viable control of field crop pests and allows the long-term and short-term forecasting of their likely occurrence, which is an important part of integrated pest management.


Investigations of the macrozoobethos in Burgas Bay (Black Sea)

E. Petrova, St. Stoykov

Abstract: The authors present studies of the zoobenthos in the Burgas Bay (Black Sea). The zoobenthos samples were taken by a determined scheme in connection with the construction of the Burgas – Alexandroupolis pipeline. The geographic location of the Bourgas Bay defines it as the deepest bay along the Bulgarian Black Sea coast. Its waters are vulnerable to potential oil spills and winds from the east, which will impact on benthic organisms. During the investigations 55 macrozoobenthos species were established distributed in four main groups: Polychaeta, Mollusca, Crustacea and “Diversa”. The total average abundance in the research area was 325 ind/m2 built mainly by the Polychaeta group and average biomass of 170 gr/m2. The general role in its construction is that of the molluscs


Preliminary study on the invasive Acizzia jamatonica (Hemiptera: Psyllidae) and its predators in Bulgaria

V. Harizanova, A. Stoeva, M. Mohamedova

Abstract. After the psyllid Acizzia jamatonica has been reported for the first time as a pest of Albizia julibrissin in Bulgaria in 2009 it has expanded its distribution. In Southern Bulgaria in 2010-2011 the pest was recorded on the examined trees in all surveyed regions: Harmanli, Balgarin, Gorski izvor, Patriarh Eftimovo, Parvomay, Kozanovo, Karadjovo, Sadovo, Yagodovo, Zvanichevo, Radinovo, Plovdiv, Burgas, Sozopol, Tzarevo, Lozenetz and Ahtopol. Naturally occurring predators from 13 species were observed to feed on the eggs and nymphs of the psyllid. Among the predators the ladybeetles, predatory bugs and soldier beetles were the most numerous. The Asian lady beetle Harmonia axyridis maintained highest population density throughout the season. Heavily infested by the psyllid leaves, buds and shoot tips were observed after the end of June which resulted in serious damages.


Susceptibility of black currant varieties grown in Troyan to Antracnose (Gloeosporium ribis) Mont. et Desm

T. Stoyanova, I. Minev, P. Minkov

Abstract. The ratio of the following black currant varieties to economically important fungal disease antracnose (Gloeosporium ribes) is examined: Neosipayushchiyasya, Bogatir, Biryulevskaya, Ometta, Titania, Lissil, Hedda, Ben Moor, Ben Tirran, Ben Sarek, Ben Lomond and Silvergieters schwarze. They are grown in a plantation without a collector’s plant-protection activities in natural background contamination. In the varieties tested in the years of the study varying degrees of attack were established. The assault index reported at Ometta and Hedda varieties varies most widely. Years characterized by more rainfall favor stronger development of the disease. For the entire period of the study with the least antracnose attack outlines the following varieties: Ben Sarek, Bogatir, Silvergieters schwarze


Impact of mineral fertilization in carp ponds on dependant environmental factors

L. Hadjinikolova, D. Terziyski, A. Ivanova

Abstract. . This study is related to the development of mineral fertilization schemes aimed at balancing the content and the N:P ratio in the water of carp ponds and its impact on main physicochemical and hydrobiological environmental factors. It was established that a triple introduction of mineral fertilizers in ponds with predetermined nitrogen and phosphorus ratio of 16:1 and the background level before fertilization of 0.52 mg.l-1 – 1.11 mg.l-1, inorganic nitrogen increased from 10.3 to 65.7 times which provides optimum average seasonal levels within 6.06 mg.l-1 – 7.04 mg.l-1 typical for application of mineral fertilization. Increase in the levels of phosphates was recorded in the 1st day after fertilization within 0.87 mg.l-1 – 1.15 mg.l-1, as the background level before fertilization was 0.05 mg.l-1 – 0.13 mg.l-1.