Annals of Agrarian Science最新文献

Endophytic actinomycetes were isolated from 6 different plants collected from Uttarakhand, India. Actinomycetes isolates were screened for their herbicidal activity against Parthenium hysterophorus, Ageratum conyzoides and Bidens biternata. These isolates belong to the seven different genera. None of the isolate showed herbicidal activity on SCN agar plates. Therefore, direct fermentation method was used for the phytotoxin production in the submerged culture to study the herbicidal activity against different test weeds. The significant differences were observed in the production of phytoxin in SCN and GS medium. In the case of Ageratum conyzoides (billygoat weed), the culture filtrate of Nocardiodes sp. 1, Nocardiodes sp.2 and Actinomadura sp. showed 60% reduction in seed germination. However, culture filtrate of endophytic actinomycetes was ineffective on seed of Bidens biternata in the pre-emergence condition. In Parthenium hysterophorus, the highest seed germination reduction was observed with the culture filtrate (in SCN) of Nocardiodes sp.1 (80%). While in GS medium, maximum inhibition was observed in culture filtrate of Saccharopolyspora sp. (80%). The culture filtrates exhibited phytotoxic activity towards the germinated seedlings of Ageratum conyzoides, Bidens biternata, and Parthenium hysterophorus showing effects like leaf curling, wilting and burning. In post-emergence condition, reduction in shoot-root length was observed with the culture filtrate of Actinomadura sp.1, Nocardiodes sp.1, Streptomyces sp.1, Saccharopolyspora sp. and Microbispora sp. These findings suggest that endophytic actinomycetes are rich source of herbicidal metabolites. Further studies are required to isolate, purify and structure elucidation of the metabolites.

The difficulties of isolation of phenoloxidases with hydroxylase activity from different plants have been discussed. Phenoloxidase with high hydroxylase activity has been isolated from tea and kivi leaves, apple (Kekhura) fruits, walnut husks and vine stems. The tea leaf phenoloxidase has been shown to be able to catalyze the hydoxylation of the natural substrate p-coumaric acid. The step in the secondary metabolism in which phenoloxidase hydroxylase activity may be included in the plant lignification process has been shown. It has been supposed that masking of hydroxylase activity of phenoloxidase might be connected with the difficulties and peculiarities of the enzyme isolation and perhaps, hydroxylase activity of perennial plant phenoloxidase is included in the process of lignin formation.

Agriculture has long been recognized as the main field of production in Egypt, Babylon, China, India … It is not accidental that we still have the most precious materials on the issues of management of this sphere, which have not lost their sensitivity to the present day. The study analyzes the individual aspects of the problem mainly on the example of ancient countries, particularly Rome. Based on the conclusion: For Platon the main thing is: The existence of natural farmland where everything is made according to demand; The land is the main sign - “mother”, which is the property of the “ideal state”. About the role of farming, Xenophon had a similar view, who first used the term “economics” and Aristotle, whose ownership is the term “economic science”; The issues of Latifundian agrarian farming research gained particular attention to Antiquity in Rome, where the specialists of Roman thinkers clearly outlined that the main field of agriculture, and the income derived from it - is the most sacred; The most effective product is near the selling markets; The importance of livestock, viticulture and gardening took place in the foreground; The objective of the science of farming is to study soil composition, selection of favorable time for land-processing tools and land cultivation; Additional work used in land cultivation ensures receiving of surplus product … Despite the experience of history, unfortunately, in post-Soviet Georgia does not pay much attention to the development of real economy, including agriculture sector.

In order to visualize the negative consequences of soil erosion processes running in Georgia, namely in the Gldaniskhevi ravine within the territory of Tbilisi, research field integrated polygon has been arranged on the eroded slope chosen beforehand.

At the control area of polygon 24 field experiments have been carried out to study the dynamics of the formed erosion processes under the different intensity precipitation conditions, whereby scour parameters were being measured (average depth – h, average width – b, B).

For estimating the exactness of calculations done on the results of measurings accomplished with the purpose to definite the intensity of soil erosion processes, the method of least squares have been used, on the base of which contour dependence between investigated parameters and therefore validity of the accomplished researches have been ascertained.

Simulative modeling of the soil erosion processes has been accomplished by means of special computer programs, which has shown, that during 167 days at the control area of the field polygon the eroded slope gulleying processes have been significantly strengthened, that nowadays can be also noticed on the slopes outside the polygon, on account of which can be concluded, that in order, to prevent expected landslide and debris flow phenomena in the river Gldaniskhevi ravine, implementation of urgent effective anti-erosive measures is needed.

Wine phenolics are important quality components that contribute to the color, taste and feel of wines. The majority of the phenolic constituents found in wine are grape-derived. In red wine, tannins and anthocyanins are the most important phenolic classes. Tannins contribute to the mouth feel of wines but they also form pigmented polymers in association with the anthocyanins to provide the stable pigments required to give red wine its long-term color stability [1,2]. Moreover, polyphenols also exert many favorable effects on human health, such as the inhibition of atherosclerosis, coronary heart disease and various cancer types [3]. By focusing on the above, our goal was to produce rose and red dry wines from Karmrahyut grape variety, which is a hybrid variety and is very little studied, and to investigate the content of anthocyanins, total phenols and monomer index in them.

Tangerine (Citrus Unshiu) is one of important agricultural crops in Georgia. As the statistical data for year 2016 manifest, the total harvest exceeds 100 thousand tons. Tangerine peel, agro-industrial waste of production of juice concentrates and jams present rich sources of valuable bioactive compounds. Due to their high bioactive compound content, tangerine peels could be applied by both pharmaceutical and food industries. In spite of this, citrus peel is usually treated as by-products or waste, resulting in environmental pollution. Citrus peels are promising source of essential oil, carotenes, natural flavanones such as hesperidin and pectin. Stepwise, sequential utilization of tangerine peel, which provides an opportunity for selective extraction of the aforementioned bioactive compounds and allows one to manage nonstandard tangerine (amounting to a third of the harvest) in a rational manner. Hence, the present study is undertaken to elaborate a feasible and effective method of sequential extraction of above mentioned bioactive compounds from tangerine peel. The first step is supercritical CO₂ extraction of essential oil. Optimal conditions for β-carotene free tangerine oil are 100 atm pressure, 35C⁰ temperature, and 15 min equilibrium time. The principal compound in Citrus Unshiu peel essential oil is d-limonene. Stepwise extraction requares correct extraction sequence of target products. Acetone (7%) was used as co-solvent in the second step of extraction. The β-carotene is soluble in acetone, whereas hesperidin is not. Optimal parameters are 150 atm, 40 °C and 1 h equilibrium, and 1 h extraction time in dynamic conditions. Methanol (7%) was used in the third step of extraction. Optimal parameters were: 250 atm pressure, 60 °C temperature, 1 h equilibrium and 30 min dynamic extraction time. At least pectin was extracted from residue of tangerin. Stepwise supercritical fluid extraction of bioactive compounds from agro-industrial waste materials is simple, effective, eco friendly separation method, which provides high quality of target products and needs one standard technological equipment.