Phytosanitary conditions of the organic field and boundary

D. Atanasova1*, V. Maneva1, N. Grozeva2

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

(Manuscript received 1 July 2016; accepted for publication 11 August 2016)

Abstract. In the field and boundary of certificated field for organic farming in the Institute of Agriculture – Karnobat have been observed and described diseases, pests and weeds in wild and cultivated plants and dependencies between them are reported. The cultural plant diversity at the certified field for organic farming is significant and amounts to 32 species and varieties of cereals. The weeds in crops and in the free areas significantly differed. In crops, the annual broadleaf weeds had greater diversity of species (Anthemis arvensis L., Lathyrus aphaca L., Papaver phoeas L., Polygonum aviculare L., Polygonum convolvulus L.) and at the boundaries – the cereal weeds (Аpera spica-venti L., Hordeum murinum L., Bromus tectorum L., Poa pratensis L.). At the adjacent areas the perennial broadleaf weeds – Cirsium arvense (L.) Scop. and Convolvulus arvensis L. were not found. At the boundaries less pest species and types of diseases were registered than in the crop fields. In cereals the most common pests are Sitobion avenae L., Aelia acuminate L., Eurygaster austriaca Schr. Beneficial insects are Coccinella septempunctata L. The most common diseases are Erysiphe graminis and Rhynchosporium secalis (Oudem.) Davis.


Effect of some soil herbicides on vegetative habits of almond trees of ‘Nonpareil’ cultivar grown in a second-year nursery field

Z. Rankova1*, M. Tityanov2

1Fruit Growing Institute, 4004 Plovdiv, 12 Ostromila, Bulgaria 2University of Forestry, 10 Kliment Ohridski, 1756 Sofia, Bulgaria

(Manuscript received 31 May 2016; accepted for publication 26 July 2016)

Abstract. The study was carried out in the period 2010 – 2012 in a nursery field established on the territory of the Fruit-Growing Institute, Plovdiv. The effect of the combined soil-applied herbicide metolachlor + oxyfluorfen (Metofen) and the contact soil herbicide with foliar activity flumioxazine (Pledge 50 WP) on the vegetative habits of ‘Nonpareil’ almond cultivar grafted on almond seedling rootstock was evaluated. In the period 15-25 March, before beginning of vegetation, soil herbicides were applied in the row strip in the second-year nursery field. The following variants were included in the study: 1. Control (untreated, hand- weeded); 2. Metofen – 120 ml/da; 3. Metofen – 240 ml/da; 4. Pledge 50 WP – 8.0 g/da; 5. Pledge 50 WP – 20.0 g/da. The effect of the herbicides on weed infestation and on the vegetative habits of the cultivar/rootstock combination ‘Nonpareil’/almond seedling rootstock was followed up. The results showed that the herbicides applied at the tested rates had a good control on weed infestation and the herbicide activity continued for 3.5-4 months. That makes it possible to eliminate the competitive impact of weeds on the development of the grafted trees for 4-5 months after beginning of vegetation. Visual symptoms of phytotoxicity (chlorosis or necrosis in the leaves and shoots) or an obvious suppression of the development of the grafted trees in the treated variants were not established. A depressing effect on growth of the grafted trees was reported after treatment with Metofen. The contact herbicide with soil and foliar activity Pledge 50 WP – 8.0 g/da can be applied for weed control in a second-year nursery field of almond trees grafted on bitter almond seedling rootstock.


Selectivity and stability of herbicides and herbicide combinations for the grain yield of maize (Zea Mays L.)

G. Delchev1*, T. Barakova2

1Department of Plant Production, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria 2Field Crops Institute, 6200 Chirpan, Bulgaria

(Manuscript received 16 May 2016; accepted for publication 9 August 2016)

Abstract. The research was conducted during 2012 – 2014 on pellic vertisol soil type. Under investigation was cycloxydim tolerant maize hybrid Ultrafox duo (Zea mays L.). Factor A included the years of investigation. Factor B included no treated check and 3 soil-applied herbicides – Adengo 465 SC (isoxaflutol + tiencarbazon) – 440 ml/ha, Wing P (pendimethalin + dimethenamid) – 4 l/ha and Lumax 538 SC (S-metolachlor + terbuthylazine + mesotrione) – 4 l/ha. Factor C included no treated check and 5 foliar-applied herbicides – Stellar 210 SL (topramezon + dicamba) – 1 l/ha, Principal plus (nicosulfuron + rimsulfuron + dicamba) – 380 g/ha, Ventum WG (foramsulfuron + iodosulfuron) – 150 g/ha, Monsun active OD (foramsulfuron + tiencarbazon) – 1.5 l/ha and Laudis OD (tembotrione) – 2 l/ha. In addition to these variants by conventional technology for maize growing one variant by Duo system technology is also included in the experiment. It includes soil-applied herbicide Merlin flex 480 SC (isoxaflutole) – 420 g/ha and tank mixture of antigraminaceous herbicide Focus ultra (cycloxydim) – 2 l/ha + antibroadleaved herbicide Kalam (tritosulfuron + dicamba) – 300 g/ha. It is found that herbicide combination of soil-applied herbicide Merlin flex with tank mixture Focus ultra + Kalam by Duo system technology leads to obtaining high grain yield. High yields of maize grain are also obtained by herbicide combinations Lumax + Principal plus, Lumax + Laudis and Wing + Principal plus. The most unstable are the non-treated check and single use of soil- applied herbicides Adengo, Wing and Lumax. Technologically the most valuable are herbicide combination Merlin flex + Focus ultra + Kalam by Duo system technology, followed by combinations of foliar-applied herbicides Principal plus and Laudis with soil-applied herbicides Adengo, Wing and Lumax by conventional technology. Single use of herbicides has low estimate due to must to combine soil-applied with foliar-applied herbicides for full control of weeds in maize crops


Influence of foliar herbicides treatment on malting barley (Hordeum vulgare L.) productivity of Emon, Vanessa and Vicky varieties

D. Atanasova*, V. Maneva

Institute of Agriculture, 8400 Karnobat, Bulgaria
(Manuscript received 1 July 2016; accepted for publication 26 August 2016)

Abstract. During the period 2012 – 2014 in the Institute of Agriculture, Karnobat a field experiment was conducted with winter malting barley varieties Emon, Vanessa and Vicky. The influence of broadleaf (dicotyledonous) herbicides alone and in their combination with wild oat (monocotyledonous) in tillering stage of the crop was studied in optimal and double doses. The herbicide selectiveness was assessed according to the EWRS scale. Yields were reported after harvest. In variety Vanessa during the treatment with Derby Super, Granstar Super, Sekator OD and combination of Puma Super 7.5 EW + Sekator OD in optimal doses, the yield does not differ from the weed control. Variety Vicky endures well the treatment with optimal doses in all of the tested herbicides, except Husar Max. In treatment with double doses, only Granstar Super does not affect negatively the yield of grain. Comparing the data from ANOVA about the role of herbicides and year conditions on the malting barley varieties it can be concluded that the yield of variety Emon is the most stable in regard to herbicides applied in optimal doses (5%), followed by Vanessa (17%) and Vicky (18%). At application of the herbicides in double doses, their influence is increased – in variety Emon up to 15%, and in varieties Vanessa and Vicky – up to 23%.


Effect of some herbicides on weeds and vines in mother plantation of Cabernet sauvignon

N. Prodanova – Marinova*

Institute of Viticulture and Enology, 5800 Pleven, Bulgaria
(Manuscript received 1630 May 2016; accepted for publication 17 August 2016)

Abstract. To maintain soil surface clean of weeds in the parent vineyard for producing cuttings for scions, the efficiency and selectivity of Gardoprim plus Gold (312.5 g/l s-metolachlor + 187.5 g/l terbuthylazine), Wing P (pendimethalin 250 g/l + dimethenamid P 212.5 g/l) and Lumax 538 SC (375 g/l s-metolachlor + 125 g/l terbuthylazine + 337.5 g/l mesotrione) at doses of 0.4 and 0.6 l/da was studied. Lumax 538 SC, Wing P and Gardoprim Plus Gold controlling efficiently annual weeds established in parent vineyard, except Xanthium strumarium L.. Lumax 538 SC and Gardoprim plus Gold showed long-term (90 days) activity. Wing P activity decreases after the thirtieth day. The tested herbicides do not damage the buds and do not lead to a reduction of shoots developed from them. Lumax 538 SC and Gardoprim plus Gold at doses of 0.4 and 0.6 l/da and Wing P at dose of 0.4 l/da do not inhibit the growth of shoots. The largest number of cuttings for scions were obtained after treatment with Lumax 538 SC.


Stone marten (Martes foina, Erxl., 1777) and villagers: human-wildlife social conflict

S. Peeva* , E. Raichev

Department of Animal Production, Monogastric and Other Animals, Faculty of Agriculture, Trakia University 6000 Stara Zagora, Bulgaria
(Manuscript received 16 May 2016; accepted for publication 8 June 2016)

Abstract. The “Human-wildlife conflict” refers to the interaction between wild animals and humans and the negative impact on their resources or wildlife and their habitats. One of the reasons for its occurrence is the entry of wild animals in urban environment. Stone marten often enters into settlements and its activity provokes conflict with humans. To clarify the attitude towards coexistence with this species a survey among 132 residents of villages in the region of Sarnena Sredna Gora Mountain was conducted in the period 01.12.2015-31.03.2016. The opinion of people familiar with stone marten’s biology (hunters) and other people (retired and active) was explored. The differences between men and women were examined. In settlements stone marten is considered to be a pest, attacking smaller livestock. Its presence disturbs humans by- displacing tiles on the roofs, noise, faeces etc., and consequently Human-wildlife conflict emerges. More than half of people are not convinced to take ultimate measures against martens. Human-stone marten conflict in Bulgarian villages is still at the tolerance level.


Investigation of the biota of Burgas Bay, Black Sea

D. Klisarova*, E. Petrova, D. Gerdzhikov, S. Stoykov

Institute of Fish Resources, 4 Primorski, 9000 Varna, Bulgaria
(Manuscript received 23 March 2016; accepted for publication 30 May 2016)

Abstract. Burgas Bay is the largest one on the Bulgarian Black Sea coast. Industrial plants along the coast as well as ports for liquid and solid cargoes create conditions of anthropogenic pressure on hydrobionts in that area. Macrozoobenthos and phytoplankton samples were collected under a specific scheme in connection with the construction of the Burgas-Alexandroupolis oil pipeline, at stations located around the designated places for unloading tankers. During the study period (2009 – 2010), 88 phytoplankton species distributed in 13 classes were identified and over 50 species of benthic species distributed in four main groups: Polychaeta, Mollusca, Crustacea and the mixed group Diversa.


Indicator polychlorinated biphenyl residues in muscle tissue of fish from Black Sea coast of Bulgaria

S. Georgieva*, M. Stancheva

Department of Chemistry, Medical University, Marin Drinov 55, 9002 Varna, Bulgaria
(Manuscript received 25 April 2016; accepted for publication 30 May 2016)

Abstract. Polychlorinated biphenyls (PCBs) are characterized by high lipophilicity and persistence in the environment and will therefore bioaccumulate and biomagnify in the food chain. PCBs were determined in muscle tissue of four fish species: goby (Neogobius melanostomus), horse mackerel (Trachurus Mediterraneus ponticus), shad (Alosa pontica pontica) and turbot (Psetta maxima maeotica). Samples were collected from Bulgarian Black Sea coast during 2007- 2011. The PCBs were analyzed in order to examine the time trends of PCB concentrations in fish from Black Sea. The six individual PCBs congeners were determined by capillary gas chromatography system with mass spectrometry detection. PCBs were found in all fish species at concentrations ranging between 2.32 ng/g ww (wet weight) and 32.87 ng/g ww in goby and shad, respectively. PCB profiles have been found to be similar in all the fish species tested. The most abundant PCB congeners in fish species were hexa- and heptachlorinated PCBs 138, 153 and 180. PCB 153 was the dominant congener in all fish studied and were found in the range from 0.95 ng/g ww (horse mackerel 2011) to 11.67 ng/g ww (shad 2010). The sum of six indicator PCBs in all fish species did not exceed the European maximum limit of 75 ng/g ww. The levels of PCBs in fish from Bulgarian Black Sea coast were found lower than in fish species from other seas – the Aegean Sea and the Mediterranean Sea.


Application of up-to-date environmental indices for assessment of seawater

D. Klisarova*, D. Gerdzhikov, E. Petrova

Institute of Fish Resources, 4 Primorski, 9000 Varna, Bulgaria
(Manuscript received 23 March 2016; accepted for publication 26 May 2016)

Abstract. The paper discusses the indices for assessment of the ecological status of seawater which are applied in the studies of algae and macrozoobenthic communities in the Bulgarian Black Sea territorial waters. They are applicable to contemporary environmental assessments in accordance with the European directives on environmental protection. Presented are also studies carried out in recent years on marine plants and bottom organisms and the resulting conclusions. The result was that we identified the ecological status of the marine ecosystem on BQE phytoplankton, macrophytobenthos and macrozoobentos from “moderate” to “good” in the period of investigation.


Productivity and quality of open field tomato after application of bio-fertilizers

H. Botеva*

Vegetable Crops Research Institute Maritsa, 32 Bezovsko shoose, 4003 Plovdiv, Bulgaria
(Manuscript received 27 April 2016; accepted for publication 31 May 2016)

Abstract. Field experiments for the effect of bio-fertilizers: Labin, Bio One, Tecamin, Agriful, Humustim and Biohumus on productivity and fruit quality of determinant tomato, variety Trapezitsa were performed on strongly leached meadow cinnamonic soil at the experimental field of the Vegetable Crops Research Institute Maritsa during the period 2008 – 2010. The fruit number per tomato plant increased up to 38.2% towards the control (without fertilization) by using bio-fertilizers Tecamin and Agriful. Similar were the results for the mass of fruits per plant, where the increase was up to 33.3% towards the control. After mineral fertilization the total tomato yield is the highest on average for the period of study. An increase of the yield in tomato with reduced mineral fertilization is established after application of bio-fertilizers 12.1% on average from 7.8% /after fertilization with Labin/ to 18.3% /after fertilization with Tecamin/ towards the control. A positive effect by fertilization with Tecamin (38.8%) and Agriful (36.3%) is established on early production. In mineral fertilization this index is lower (23.7%). Bio-fertilizers Tecamin and Agriful have a positive effect on the content of vitamin C and dry matter.