Central Balkan Mountains Research Articles

INFLUENCE OF SOWING PERIOD ON THE FORAGE PRODUCTIVITY AND WEED INFESTATION OF ANNUAL WINTER CEREAL AND LEGUME CROP

During the 2011–2012 period in the Research Institute of Mountain Stockbreeding and Agriculture (RIMSA) in Troyan (Bulgaria) the effect of sowing time on some bio–productive indicators (green mass and dry matter yields, weed infestation) of the forage from annual winter cereal and legume mixture of winter barley and winter pea was performed. As variants the following sowing periods carried out during 10 days were studied: 1. 20–30 September (Standard); 2. 1– 10 October; 3. 11–20 October; 4. 21–30 October. It was established that the most optimal time for sowing of mixed crop grown under foothill conditions of the Central Balkan Mountains (Troyan region) is the period from 1 to 20 October. The received forage amounted to 2.38 t.ha green mass and 0.59 t.ha dry mass, which exceeded the standard sowing period (20–30 September) with 25.26% and 59.46%, respectively. Irrespective of the autumn sowing period, weed infestation of the crop of winter cereal–legume mixture was comparatively low, ranging from 0.74 to 4.88%.

CHANGES OF SOME FORAGE INDICATORS DEPENDING ON SOWING PERIOD OF ANNUAL LATE–SPRING CEREAL AND LEGUME CROP

During the 2010–2012 period in the Research Institute of Mountain Stockbreeding and Agriculture (RIMSA) in Troyan (Bulgaria) the effect of sowing time on some bio–productive indicators (green mass and dry matter yields, weed infestation) of the forage from annual late– spring cereal and legume mixture from maize and white lupine was performed. As variants the following periods of sowing (during 10 days) were studied: 1. 10–20 April (Standard); 2. 21–30 April; 3. 1–10 May; 4. 11–20 May. The most optimal sowing time of annual late–spring mixed crop from maize and white lupine grown under foothill conditions of the Central Balkan Mountains (Troyan region) is the period from 10 to 20 April. The received forage amounted to 2.53 t.ha green mass and 0.39 t.ha dry matter; while in the others later periods the yields were relatively low. A less weed infestation of the mixed crop was reported at the earlier periods of sowing.

Variation of some chemical indicators in forage of annual winter pure and mixed crops cultivated in Central Balkan Mountains (Bulgaria)

Abstract The aim of this experiment was to determine the variations in some important chemical indicators of annual winter cereal and legume pure and mixed crops for green forage production under the conditions of the fore-mountain regions of the Central Northern Bulgaria (Troyan region). In pure crops the crude protein content had fewer values compared to mixed crops. The cereals accumulated less crude fat in comparison with legumes. In mixed crops the crude fat was from 1.99 to 2.82%, with a relatively lower coefficient of variation in comparison with pure crops. More crude fibre was indicated in winter barley, triticale and winter vetch. All pure crops displayed a low coefficient of variation (from 7.21% to 10.26%). The lowest values of crude fibre were in the mixed crops with winter pea and they had a lower coefficient of variation compared to pure crops. In regard to crude ash content the legumes exceeded the cereals. In the legume pure crops a low coefficient of variation was established, while in cereals it was a medial value. On the whole all mixed crops had a low coefficient of variation. In legumes the calcium content was higher but with a low coefficient of variation than cereals. In mixed crops irrespective of whether it had a cereal or legume component the calcium content in forage varied from 0.530 to 0.870%. In mixtures the calcium variation was mostly with a medial value. The phosphorus content had lower values in forage of pure and mixed crops. The least variation (as a medial value) was observed in winter vetch and winter barley. In mixed crops with winter barley this indicator had a low coefficient of variation. The most favorable proportion between calcium and phosphorus for pure crops was found in cereals (triticale and winter barley) - respectively 2.46 and 2.23 and for mixed crops - in Winter barley+winter pea and Winter barley+winter vetch - from 1.76 to 2.57.

POSSIBILITIES FOR ORGANIC PRODUCTION OF PLUM FRUITS FROM THE 'CACANSKA LEPOTICA' CULTIVAR BY APPLYING TRENCH PLANTING

The experiment was carried out in the region of the Central Balkan Mountains of Bulgaria during the 1998-2007 period. Possibilities for the use of organic fertilizers applied at the time of tree planting, in previously made trenches, were studied. The used fertilizers were obtained by composting manure and an apple waste product from apple processing. Mineralization of some major nutrients was observed and it was found that during 10 years, optimum levels of nitrogen, phosphorus, potassium and content of humus were maintained in the root system zone without need for corrections, by applying mineral fertilizers. The trees in all three treatments showed normal development and fruit-bearing.

THE PLUM CULTIVAR 'JOJO' GROWN UNDER THE CONDITIONS OF THE CENTRAL BALKAN MOUNTAINS IN BULGARIA

The region of the Central Balkan Mountains is characterized by a high density of Plum pox virus. Therefore, plum producers have been using tolerant cultivars, mainly 'Stanley', on a large scale. As an alternative, in 2003 the Plum pox resistant cultivar 'Jojo' was introduced into the region of Troyan and subjected to evaluation. 'Jojo' was grafted on rootstocks 'Saint Julien A' and 'Fereley-Jaspi'. Without irrigation, until the age of five years the trees on rootstock 'Fereley' showed moderate to strong growth, with compact crowns and with abundant flower buds. Those on 'Saint Julien A' had weaker growth and 50% of them died by 2006. First fruit was registered in the second year after planting (2004) and a real yield of 3-5 kg per tree was obtained in 2005. The fruits were dark-blue colored, ripened at almost the same time as cultivar 'Stanley', and had, on average, 8-10 g more weight and a larger stone. The fruit flesh was very thick, with a sweet-acid taste and was freestone. They are suitable for fresh consumption and for processing. During a 5-year period, under conditions of very high PPV infection background, the aphids on 8% of the trees on rootstock 'Fereley' became infected. No presence of the virus in trees of 'Jojo' was detected, however.

Late Alpine deformations, Neotectonic evolution and Active tectonics of the southern border of Central Balkan Mountain: a new contribution

The published till now data and interpretations show the dominant role of the active faults in the structures of Karlovo and Sheynovo grabens and along the southern slope of the Central Balkan Mountain. The new investigations along the southern border of the Balkan Mountain included studies of faulting and fracturing at micro and mezzo-levels. A quantity of striae on slickensides and shear joints were measured. Thin sections have been prepared from five samples collected from outcrops of the surface of thrusting of the big granite over-thrust. The microscope analyses have shown that the process of thrusting was in low-temperature conditions. The secondary deformations at micro-level are reflections of the next tectonic impacts. Geophysical information has been also analysed (data from the seismic profiling, as well as reinterpretations of the gravity field). The tectonic stress fields from the Early-Alpine time till now have been reconstructed. For the first time it has been proved the existence of deformations from the Atean phase (Late Miocene) along the southern slope of the Balkan Mountains. This stress field is characterised by sub-horizontal and NE—SW directed axis s3 and axis s1 varying from subvertical to NW—SE direction. The youngest tectonic stress field has dominant N—S extension. The main conclusion of the study is that it was not possible to find proves for the existence of significant fault extended along the southern slope of the Balkan Mountains. A combination of fault structures is present, some of them being old surfaces of over-thrusting. No traits of recent active tectonic were found, and the seismicity is very low. It can be assumed that the recent movements are facilitated by listric-type faults, and this is related to the change of the bedding angle of the sediments filling the adjacent young basins.

Productive indices of sheep breeds and varieties reared in the conditions of Central Balkan mountains

Main productive indicators (live weight, wool-yield, wool length, economic fertility, biological fertility) at different ages of sheep from Karakachanska breed and Local Sredno Staroplaninsko and Tetevensko varieties were examined. The results showed that the sheep from Tetevensko variety indicated the highest values of live weight from the birth to 3.5 years of age, and the lowest - those from Karakachanska breed. The highest value of mean daily growth was examined from the birth to 3-months age in all groups of the study. It was highest for Tetevensko variety - 0.240 kg and for Karakachanska breed - the lowest, 0.217 kg, respectively. The highest wool-yield in all groups was at 18-months age - Karakachanska breed - 3.65 kg, Sredno Staroplaninsko variety - 3.42 kg, Tetevensko variety - 3.75 kg and with age it decreased. The sheep from Karakachanska breed at 18-months age were with the longest wool - 28.15 cm, and with the shortest one from Tetevensko variety at 4.5-years of age- 13.03 cm. With age it decreased insignificantly in all groups. The sheep from Tetevensko variety, followed by those from Local Sredno Staroplaninsko variety, indicated the highest values of economic and biological fertility.

Amino acid composition of milk from Tsigai and Karakachanska sheep breeds reared in the Central Balkan mountains region

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Some traces of interlinguistic contacts in the central Balkan mountains

The etymology of three Balkan tree names, S.-Cr. munika ‘Pinus leucodermis' molika ‘Pinus peuce' and omorika ‘Picea omorika' is discussed. The latter is supposed to go back, together with Bulg. morika ‘spruce', to Slavic *mъxorъ ‘fringe' describing here the hanging branches of spruce. The Bosnian pine munika, munjika growing in high and rocky places exposed to the thunder, the relation to S.-Cr. munja < Common Slavic *mъlnja seems probable, and molika may be explained as a re-borrowing from Alb. molikë traceable to the same Slavic prototype *mъlnika.

Grammoceras, Pseudogrammoceras et Podagrosites (Grammoceratinae, Ammonitina) du Toarcien supérieur dans la région du Balkan (Bulgarie). Taxonomie et biostratigraphie

This paper presents the results of taxonomic and biostratigraphic investigations on the Upper Toarcian ammonite genera Grammoceras, Pseudogrammoceras and Podagrosites, derived from the Ozirovo Formation in the Western and Central Balkan Mountains (Bulgaria). It is based on the re-examination of almost all of old Bulgarian material, collected from the middle of the 40s to the end of 60s of last century, as well as on the ammonites obtained by the author in some new localities in course of the last few years. 23 taxa of species group of these three genera are described and figured. The Grammoceras thouarsense, Pseudogrammoceras mediterraneum and Pseudogrammoceras fallaciosum ammonite Biozones are described and compared to their contemporaneous equivalents of the zonal scheme proposed for the Toarcian by French Jurassic Working Group (Elmi, Rulleau, Gabilly &amp; Mouterde, 1997).

Aalenian and Lowermost Bajocian ammonites (Hammatoceratinae and early Otoitidae) from the Western and Central Balkan Mountains (Bulgaria)

Five taxa of the species group, belonging to the subfamily Hammatoceratinae and one species ofthe family Otoitidae are described and figured in the present paper, for the first time in this country. From the subfamily Hammatoceratinae they are Pseudammatoceras subinsigne (Oppel, 1856), Pseudammatoceras cf. ornatum Elmi, 1963, Pseudammatoceras broilii (Renz, 1925), Planammatoceras planiforme Buckman, 1922 (Aalenian, Ludwigia murchisonae Zone) and Parammatoceras boyeri Elmi, 1963 (Aalenian, Graphoceras concavum Zone), and from the family Otoitidae - Docidoceras cf. cylindroides Buckman, 1919 (Lower Bajocian, Hyperlioceras discites Zone).

Jurassic stratigraphy and geodynamics in the eastern part of the Central Balkan Mountains (Gabrovo and Kazanluk Districts), Bulgaria

Seven instructive Jurassic sections in the Gabrovo and the Kazanluk Districts are described. It was established that in the Gabrovo District the lower part of the Ozirovo Formation belongs to the Lower Sinemurian, and the underlying Kostina Formation to the Hettangian. In the Kazanluk District (section in the locality Ikischa) the lower part of the Ozirovo Formation belongs to the Lower Pliensbachian, and the Kostina Formation to the Upper Sinemurian. The sections in the Gabrovo District are situated within the limits of the Kostina Step (second order block) of the Izdremets Complex Graben of the Moesian Early- Middle Jurassic Platform. The sections in the Kazanluk District are situated within the Neshkovtsi Step of the same graben. The marine ingression on the Moesian Early-Middle Jurassic Platform began during the Hettangian with the most descended Kostina Step. The sea advanced from the Toundzha Fault-Angle Valley. During the Sinemurian and the Early Pliensbachian the ingression expanded and covered all the rest, more uplifted steps of the Izdremets Graben. The sea gradually overflowed the Sevlievo Graben and the western part of the Veliko Turnovo Graben of the Moesian Early-Middle Jurassic Platform. At the initial stage of the marine ingression the supplying dryland was active, therefore quite shallow water terrigenousclastic sediments and very little amount of more or less sandy calcareous silts with bioclasts were deposited. Later on (at the end of the Sinemurian and in the beginning of the Pliensbachian) the calcareous silts began to prevail over the terrigenous sediments, the shallow-water environments having remained. More or less significant Middle Jurassic and Early Jurassic stratigraphic breaks were established in all of the described sections. They realized in marine conditions. Strong submarine currents led to a marine abrasion. As a result, condensed Middle-Upper Callovian limestones lie at present over Lower Bajocian or Lower Sinemurian sediments, or directly overlay Upper Triassic rocks. In the section near the Sokolski Monastery, Gabrovo District, Middle Kimmeridgian limy shales to marls and a quite limited amount of thin layered limy sandstone intercalations directly overlie Lower Sinemurian, sandy bioclastic limestones.