Annals of Agrarian Science最新文献

Christ's thorn formation (Paliureta spina-christi) of Tbilisi environs is studied. This formation is one of the typical representatives of hemixerophilous shrubberies of shibliak type in the Caucasus region and one of the characteristic for vegetation cover of Tbilisi surroundings. Plant communities of Christ's thorn formation with different plots area are fragmentary spread almost all over the territory of Tbilisi environs from 400 to 800 (900) m above s.l.. Plant communities are developed on slopes and plane place with various exposure and inclination, mainly on the grey-cinnamonic and cinnamonic soils. The most xerophilous variants are developed on the erosive bare mother rocks as well. In Tbilisi environs the Christ-thorn's plant communities are either primary or secondary origin. Formation is characterized by rich typological and floristic composition. We identified 6 plant communities: (1) Paliureto-mixtofruticetum gramino-mixtoherbosum, (2) Paliureto-Rhmanetum gramino-mixtoherbosum, (3) Paliureto gramino-mixtoherbosum, (4) Paliureto bothriochlooso gramino-mixtoherbosum, (5) Paliuretum festuceto-bothriochloosum, (6) Paliureto-Astragaleto-Rhamnetum. For each separated plant communities the basic structural characteristics (general projective coverage, projective coverage, distribution and height of layers, sodding degree, dominant-edificator plants, characteristic species, number of species, moss cover, litter, species richness, spectrum of life forms), distribution area in the Tbilisi environs and main physical-geographical conditions (topography, altitude, exposure, inclination, soil type) are given. 190 species of vascular plants, which belong to 40 families and 132 genera, were recorded. In the floristic spectrum leading families are: 1. Poaceae – 27 species (14,2%), 2. Asteraceae – 25 species (13,2%), 3. Fabaceae – 17 species (8,9%), 4-5. Lamiaceae and Rosaceae – 15-15 species (7,9-7,9%), 6-8. Apiaceae, Caryophyllaceae and Rubiaceae – 8-8 species (4,2-4,2%), 9. Brassicaceae – 7 species (3,7%), 10-11. Caprifoliaceae and Rhamnaceae – 4-4 species (2,1-2,1%). The life form spectrum is as follows: hemicryptophytes (including biennials) – 91 (47,9%), therophytes – 58 species (30,5%), phanerophytes – 21 (11,1%), chamaephytes – 7 (3,7%), geophytes – 13 (6,8%). The article is attached full list of recorded plants.

This work was aimed to explore rhamnolipid production under solid state fermentation using a potential substrate mahua oil cake and to evaluate the biocontrol efficacy of rhamnolipid against Fusarium wilt of eggplant. The combination of Response Surface Methodology and Central Composite Design was employed to optimize higher biosurfactant production. Therefore, four factors viz., substrate concentration, inoculum size, pH and temperature were selected for optimization of rhamnolipid production. The results revealed that the optimum conditions for reduction of surface tension were mahua oil cake 7.78 g, 2.4 ml inoculum size (1 × 10⁸ cells/ml), pH 7 and 30° C temperature. To evaluate the biocontrol efficacy the application of rhamnolipid at various concentrations (0, 100, 250 and 500 μg/ml) by soil and foliar application were employed in the pot culture assay. In vitro study indicated that rhamnolipid producing strain SNAU02 was the most effective antagonist against Fusarium oxysporum f. sp. melongenae and used for pot culture study. On the basis of economic analysis, treatment T₉ (Fusarium oxysporum f. sp. Melongenae ( × 10⁶ spores/ml) + 50 ml of 250 μg biosurfactant/ml to soil + foliar spraying of biosurfactant (250 μg/ml) ranked among the efficacious treatments and was just as effective as a synthetic fungicide. In control treatment, occurrence of disease severity and disease incidence was observed from early stage of crop growth until harvest stage. The pot experiment results indicated that SNAU02 rhamnolipid could be a promising agent in the biocontrol of Fusarium wilt of eggplant, which might help to minimize the yield loss of eggplant.

In this study, LULC changes are investigated by using Remote Sensing (RS) and Geographic Information Systems (GIS) in Tbilisi, capital of Georgia. A number of factors contribute to the changes in the LULC. Rapid urbanisation has led to dramatic changes in land use practice. The expansion of the population of Tbilisi peaked in the 1970s. This resulted in a high demand for living space and an active phase of urbanisation of the outskirts of Tbilisi begun, ending with the collapse of most social systems after the dissolution of the USSR in 1991. A new wave of urbanisation hit the city in the beginning of the 2000s. This process was accelerated by the incorporation of nearby recreational zones into the city's administrative area in 2007. In this study, digital image processing was used in the analysis and assessment of the land use changes since 1987 throughout 2016. After the classification of the Landsat 5 and Landsat 8 OLI it became apparent that there were 5 different classes of LULCs. The change in the size of the surface area of each class during the previous 29 years was also determined. Sharp rise in the built-up area was discovered after the change detection. Built-up area increased 13.9% in 2016 compare with 1987. Therefore, available data on LULC changes can provide critical input to decision-making of environmental management and planning the future.

Soil cultivation, seed sowing, crop care and harvesting - these are the main technological processes in the field – husbandry of mechanized agriculture, the qualitative and effective performing of that depends on highly professional, organized and modern service backup, determined by its main result - to obtain a high-quality harvest. The service of agricultural technological processes in the first line provides their provision with the corresponding necessary and serviceable technical means, both in power generating and technology systems [1,2]. In addition, to carry out these processes in a strictly defined agro technical terms, their continuous provision with material and technical means (fuel and lubricants, spare parts, etc.) and professional engineering and technical departments is necessary.

Soil erosion is a very complicated process. Rainfall erosivity is one of the main factors affecting on soil erosion. The erosive power of precipitation is accounted for by the rainfall erosivity factor (R-factor). Rainfall erosivity (R-factor) itself is a very important factor in soil erosion modeling. R-factor is a product of rainfall kinetic energy and rainfall intensity. Rainfall intensity change is one of the main indicators of climate change. It has a great influence on agriculture as one of the main factors causing soil erosion. Information of rainfall erosivity is rarely available with good spatial and temporal coverage. Accurate estimation of rainfall erosivity requires continuous rainfall data. Because many parts of the world still do not have detailed rainfall intensity data available, many studies have been performed to estimate R-factor based on available rainfall data. There are several alternative methods cited in science literature. This study aims to evaluate the temporal as well as the spatial distribution of rainfall erosivity and to calculate average annual rainfall erosivity for three study periods (1936–1962; 1963–1989; 1990–2016) in Kakheti, east Georgia. As far as Kakheti is the agrarian region, frequency and intensity of the rain are very important factors in agriculture point of view. Our study provides the assessment of rainfall erosivity potential with use of modern research methods for five weather stations (Telavi, Gurjaani, Sagarejo, Dedoplistskaro and Lagodekhi) in Kakheti. Rainfall erosivity potential was determined for every weather stations in Kakheti region from literature and records from meteorological stations. Then the same factor was determined by the selected methods (for each method separately), and the outcomes was compared, which allows us to determine the validity of a particular method for the study area. From the three methods used in the study process, method by Loureiro & Cautinho was finally used for the assessment rainfall erosivity during three study periods.

Indoor air heating and cooling is responsible for a large fraction of energy use in Georgia. Heating and cooling degree days are measures that reflect the amount of energy needed to heat or cool a building to a comfortable temperature, considering how cold or hot it is outside.

The purpose of the presented research is to estimate and study variations and trends of heating and cooling degree days for different locations in Georgia for the base period defined by the World Meteorological Organization (1961–1990). To achieve this goal, air temperature daily values were used for fourteen different locations within Georgia, covering 1961–1990 year period. The daily, monthly and annual numbers of cooling and heating degree days have been estimated for various locations and also their spatial distribution have been studied. Heating degree days were calculated at a base temperature of 18 °C and cooling degree days at a base temperature of 26 °C.

The obtained results are significant to study energy demand and resolve environmental issues associated with energy consumption in Georgia.