Occurrence of Pseudomonas syringae pv. tomato in Bulgaria

M. Stoyanova1*, K. Aleksandrova1, D. Ganeva2, N. Bogatzevska1

1Institute of Soil Science, Agrotechnologies and Plant Protection, Nikola Pushkarov, 7 Shosse Bankya, 1331 Sofia, Bulgaria 2Vegetable Crops Research Institute Maritsa, 32 Brezovsko shose, 4000 Plovdiv, Bulgaria

Abstract. Bacterial speck of tomato caused by Pseudomonas syringae pv. tomato is an important disease in many tomato growing areas. The pathogen is known to comprise two races – R0 and R1. Sixty-seven pathogenic strains isolated in the period 2000 – 2013 from tomatoes with symptoms of bacterial speck in Bulgaria were the object of this study. The isolates were identified as P. syringae pv. tomato by the miniaturized Biolog system and possess the typical metabolic profile for the species. The pathogenic population of P. syringae pv. tomato in Bulgaria is homogeneous by phenotypic characteristics. The races of the strains were determined. On the base of the obtained results and the data available in the literature for the country, the proportions of the occurrence of the two races since 1985 alter cyclically with a tendency for shortening the cycle. The changes in the spread and development of the disease are related to the climatic changes.


Investigation the influence of dietary fiber on the rheological properties of alginate beads

Z. Manev1*, N. Petkova2, P. Denev2, D. Ludneva1, S. Zhelyazkov1

1Food Research and Development Institute, 154 Vasil Aprilov, 4003 Plovdiv, Bulgaria
2Department of Organic Chemistry, Technological Faculty, University of Food Technologies, 26 Maritza, 4002 Plovdiv, Bulgaria

Abstract. During the current investigation experiments for the preparation of alginate beads with aqueous solutions of sodium alginate, calcium lactate or calcium dichloride and dietary fiber in different concentrations: inulin with varying degrees of polymerization, wheat bran and amidated apple pectin were carried out. The sodium alginate solutions were at constant concentration 3%, while calcium salts in 7% were applied for bead formation. It was proven that the rupture force of alginate beads was always higher than the pure model system regardless of the chemical structure of dietary fibers used. In the result of the carried research the dependence at a certain concentration was established at which the rupture force and deformation of the beads increased gradually.


Correcting the breadmaking quality of flour damaged by Sunn pest (Eurygaster integriceps) by using apple pectin

I. Stoeva*

Dobrudzha Agricultural Institute, 9520 General Toshevo, Bulgaria

Abstract. This paper considers the use of apple pectin as a means of correcting the technological and baking properties of flours from wheat cultivars of different quality (Pryaspa, Enola, Pobeda, Aglika, Albena, Iveta, Zlatina, Lazarka, Kalina and Kiara) with 2.5% damage by Sunn pest. It was found out that the 2.5% damages caused by Sunn pest did not significantly affect the quality of the investigated cultivars. The studied wheat cultivars demonstrated specific reaction to the added pectin. The use of pectin provoked positive changes in the sedimentation value of cultivars Aglika, Albena, Iveta, Zlatina, Lazarka and Kalina. The negative effect of pectin on the amount of the wet gluten in 70% flour depended of the cultivar’s genotype. Greatest differences in the amount of wet gluten in comparison to the check cultivar were found in Kalina and Kiara (quality group C) and lower in Lazarka (quality group B). The effect of pectin was expressed in greater water absorption of the flours, time for dough formation and dough relaxation. The farinograph number quality increased in all investigated flours but rarely exceeded significantly the norms for the respective quality groups. Positive effect of apple pectin on the baking properties was established in all investigated cultivars. Form resistance and crumb quality were improved. The pores were small and evenly distributed, and the crust color was more intensive. Significant positive variations in the values of volume and form resistance of bread in comparison to the checks were found in cultivars Kalina, Lazarka and Kiara.


Storage and its effect on the antioxidant capacity of dried Bulgarian Chrysanthemum balsamita L.

A. Popova1*, D. Mihaylova2, I. Alexieva1

1Department of Catering and Tourism, Faculty of Economics, University of Food Technologies, 26 Maritsa, 4000 Plovdiv, Bulgaria 2Department of Biotechnology, Technological Faculty, University of Food Technologies, 26 Maritsa, 4000 Plovdiv, Bulgaria

Abstract. The aim of the present study was to extend the knowledge of Chrysanthemum balsamita due to the scanty data concerning the constituents, properties and the possible benefits of using this plant. Three extraction techniques were conducted in order to explore the effect of storing over the antioxidant potential of dryChrysanthemum balsamita L. samples. Two solvents – water and 70% ethanol were applied and several reliable procedures such as 2.2- diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2.2-azinobis-3ethyl benxothiazoline-6-sulphonic acid (ABTS) cation decolorization activity and the ferric reducing antioxidant potential method (FRAP) were carried out in order to evaluate the antioxidant capacity of the different extracts. The results of all extracts varied significantly before and after storing the plant samplefor twelve months. The total phenolic content of the dried leaves was established to be in range of 7.63 ± 0.066 –11.87 ± 0.064 mg GAE/g PW of the stored leaves. Based on the results this less explored in Bulgaria plant could be used as apotential source of biologically active substances with beneficial effect.


Mixed viral infections in tomato as a precondition for economic loss

N. Petrov*

Institute of Soil Science, Agro Technologies and Plant Protection Nikola Pushkarov, 7 Shosse Bankya, 1331 Sofia, Bulgaria

Abstract. Tomato is one of the economically important crops in Bulgaria. Low tomato yields in the country are mostly due to lack of knowledge on sustainable agronomic practices, lack of improved varieties, which are well suited for high yield and resistance to diseases, and also due to damage caused by pests and diseases. Many viruses infect the tomato crop. The object of this research was to identify viruses infecting tomato crops in Bulgaria. The presence or absence of a viral infection in tomato plants was carried out with DAS-ELISA serologic assays with specific polyclonal immunoglobulin G for the relevant plant virus. Most of the tomato plants were infected with one or two viruses and in rare cases with more than two viruses. We found that mixed viral infections caused more severe necrotic damages in the tomato fruits and increased the economic loss compared with mono infections.


Bioconversion of nitrogen in an eco-technical system for egg production

A. Gencheva*

Nature Sciences Department, New Bulgarian University, 21 Montevideo, 1618 Sofia, Bulgaria

Abstract. The present paper aims to assess nitrogen circulation in an eco-technical system for egg production. The experiments were conducted in modelled conditions in an anthropogenic ecosystem of the “mesocosm” type, in which the unit of the bio-consumers and three eco-technological chains modelling the unit of the bio-decomposers are modelled: manure storing for decontamination /a recommendation on good farming practices/, composting and anaerobic decomposition in an installation for biogas production. A new criterion was implemented for the assessment of the chemical heterogeneity in the biogenic nitrogen cycle in the modified trophic chain – retention coefficient /k/, which is defined as the ratio of nitrogen introduced into the system / nitrogen content in the feed: its quantity in the secondary biological production x 100. The chemical heterogeneity at the level of organisms /differences in the individual components of eggs/ and at the biocenotic level is established. The biogenic nitrogen cycle in the eco-technical chain for egg production is characterized by an uneven distribution in both products of the outflow. The largest amount of nitrogen is found in the egg whites (k = 0.45), while it decreases significantly in egg yolks (k = 0.17) and reaches k = 0.03 in the egg shell, a.k.a. heterogeneity on the level of organisms is established. The nitrogen compounds introduced through the feed ration are concentrated in manure (k = 25.33). Losses of nitrogen are established in two of the manure utilization technologies. The quantity of /k/ in the compost is 20.32, a.k.a. the loss of nitrogen compounds is 19.8%. The biggest losses are found in manure storage; according to the recommendations on good farming practices (k = 18.82) or the reduction of nitrogen is 25.7% compared with fresh manure. Due to redistribution of the chemical elements /a significant part of C, H and O are included in biogas/, there is nitrogen concentration in bio slime – k = 35.85 or 41.5% more than in fresh manure. When separated nitrogen is concentrated in the liquid fraction (k = 31.19), while in the solid phase k = 4.67 is established.


Contemporary state of macrophytobenthos along the Bulgarian coast of the Black Sea

D. Petrova*, V. Vachkova, D. Gerdzhikov

Institute of Fish Resources, 4 Primorski, 9000 Varna, Bulgaria

Abstract. The contemporary assessment of macroalgal species distribution is based on qualitative and quantitative parameters (taxonomy, abundance, biomass, seasonal dynamics, habitat description, etc.) and indices of phytobenthos diversity. The analyses made in the period 2011 – 2012 allowed to define the ecological status of coastal water bodies (one-mile zone) as a dynamic variation from “very poor” to “very good”. An improvement was established from north to south, explainable by the prevailing anthropogenic pollution in the northern Bulgarian coastal zone – active recreational activities, industry and impact of transformed waters from the Danube. The aim was to carry out an ecological assessment of the Bulgarian coastal waters of the Black sea using the biological quality element (BQE) – macrophytobenthos according to the requirements of the Water Framework Directive (WFD 2000/EC).


Evaluation on reaction of late maturing maize hybrids and lines to Fusarium ear rot.

M. Haddadi1*, M. Zamani2

1Agricultural and Natural Resources Research Center of Mazandran, Sari, Iran
2Maize and Forage Crops Research Department, Seed and Plant Improvement Institute, Karaj, Iran

Abstract.InordertoevaluateanddetermineresistanceratesofdifferentcorngenotypestoFusariumearrot,22inbredlinesand19 lateandmediummaturity hybrids in 2009 and 17 inbred lines and 14 late and medium maturity hybrids were planted in Qarakheil Agricultural Research Station in 2010. Each line and hybrid were planted separately. For each experiment a randomized complete block design with three replications was used. Plant ears were inoculated by Nail Punch method at the 10th day after anthesis. When the disease symptoms were observed, evaluation of each line and genotype was done based on percentage and severity of the disease symptom. The result in 2009 showed that 14 hybrids were tolerant. Hybrids of K3640/3 X MO17, K166B X K18, K166B X K19/1 and K3547/4 X MO17 were resistant. One hybrid was susceptible. Pure lines of K18 and K LM77007/7-2-6-3-1-2-1 were resistant. 14 tolerance lines and 6 susceptible lines were shown. In 2010 hybrids of K166B X K18 and K3653/2 X K18 were resistant. The other hybrids were tolerant. Pure lines of K3547/3 and K18 were resistant. Five tolerance lines were also shown.


Assessment of Bulgarian Black Sea coastal water using the biological quality element phytoplankton

D. Petrova*, D. Gerdzhikov

Institute of Fish Resources, 4 Primorski, 9000 Varna, Bulgaria

Abstract. The aim of this paper was to study and assess the quality of Bulgarian Black Sea coastal water using the biological quality element phytoplankton communities, according to the requirements of the Water Framework Directive (WFD EU, 2000) and the developed reference values. A total of 134 species of microalgae were identified among which dominated the complex Bacillariophyceae/Dinophyceae (72.39 %). There was an improvement of the ecological status in three to six points from September to November 2011 (Krapetz, Shabla, Kamchiya, Dvoynitsa, Nessebar, Sozopol). This was due to the better characteristics of the phytoplankton community referring to Shannon index, number of species, Sheldon index, %MEC, DE% and Chl-a. Phytoplankton blooms were recorded in Krapetz, Varvara and Nessebar in September and in Albena, Varna-North, Sarafovo and Rosenets in November. Studies conducted have contributed to contemporary assessment of the water status in the one-mile area within the National Environmental Monitoring System (NEMS).



Species composition and density of weeds in a wheat crop depending on the soil tillage system in crop rotation

P. Yankov1*, M. Nankova2, M. Drumeva1, D. Plamenov1, B. Klochkov2

1Department of Plant Production, Faculty of Marine Sciences and Ecology, Technical University Varna, 1 Studentska, 9010 Varna, Bulgaria 2Dobrudzha Agricultural Institute, 9520 General Toshevo, Bulgaria

Abstract. The investigation was carried out in the trial field of Dobrudzha Agricultural Institute, General Toshevo on slightly leached chernozem soil type. For the purposes of this investigation, variants from a stationary field experiment initiated in 1987 and based on various soil tillage tools and operations were analyzed. The species composition and density of weeds were followed in a wheat crop grown after grain maize using the following soil tillage systems: plowing at24–26cm(formaize)–diskingat10–12cm(forwheat);cuttingat24–26cm(formaize)–cuttingat8–10cm(forwheat);diskingat10–12cm(formaize)– disking at 10 – 12 cm (for wheat); no-tillage (for maize) – no-tillage (for wheat).Weed infestation was read at the fourth rotation since the initiation of the trial. The observations were made in spring before treatment of the crop with herbicides. The soil tillage system had a significant effect on the species composition and density of weeds in the field with wheat grown after previous crop maize. The long-term alternation of plowing with disking in parallel with the usage of chemicals for weed control lead to lower weed infestation of the weed crop. The lower weed density after this soil tillage system was not related to changes in the species composition and the relative percent of the individual species in the total weed infestation. The long-term application in crop rotation of systems without turning of the soil layer and of minimal and no-tillage increased the amount of weeds. The reason is the greater variability of weed species which typically occur after shallow soil tillage.