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The field study was carried out between 2000 and 2003. The plants of Sparaxis tricolor were sprayed twice prior to flowering with a fertilizer called titanium (0.8% Ti) in three concentrations: 0.02, 0.04 and 0.08%. Application of titanium in the concentration of 0.04% increases the total yield of corms by 20% on average and the commercial yield by 7%. Spraying the plants with titanium in the concentration of 0.02% increased the share of corms with > 5cm circumference in total yield and improved yield structure of corms of the first selection. A higher concentration of the preparation (0.08%) had unfavorable effect on the commercial yield of corms. In 2001 titanium applied in the concentration of 0.02% increased the nitrogen content in offspring corms and decreased content of other macro-elements. In 2003 offspring corms of plants treated with titanium in the concentration of 0.02–0.04% had more dry weight, N, P, K, Ca, Mg and Na.
Permanent grassland is a valuable source of valuable natural raw material for production of fodders. The fodder value of sward depends on the grass yield volume, agricultural value (UVN), content of minerals, etc. The present paper discusses the results of a study conducted in 2009-2011, on permanent grassland situated in the valley of the Por River. Samples of the plant material were taken before the first cut from selected, representative areas. They were used to assess, with basic analytical and statistical methods, the yielding, agricultural value (UVN) and chemical composition of hay. The content of P, K, Ca and Mg was determined in the dry weight of the sward by Flame Atomic Absorption Spectroscopy (FAAS), while the total content of N was established by the Kjeldahl’s method. For easier interpretation of the results, the classified syntaxons (Matuszkiewicz 2006) were ranked into higher syntaxonomic units. The present research showed a fairly good content of P, Mg and Ca in the analyzed dry weight of plants, enough to satisfy the nutritional demand of ruminants. However, the total content of N and K in the plant samples was insufficient. The agricultural value (UVN) of the dry weight of plants and the yield volume of the examined phytocenoses were varied, which was statistically verified. The high value of variability coefficients also testifies to the considerable differentiation of all the analyzed features within particular syntaxonomic units.
This study investigates the influence of extraction system on the extractability of polyphenol compounds and antioxidant activity of various medicinal plants. Oxygen radical absorbance capacity (ORAC) and total polyphenol content of 25 Bulgarian medicinal plants subjected to water or 80 % acetone extractions were investigated and compared. The type of extragent significantly influenced the efficiency of the polyphenol extraction and the antioxidant activity. In all cases ORAC results and total polyphenol content were higher for acetone extraction than for water extraction. The acetone extract of peppermint had the highest ORAC value - 2917 μmol Trolox equivalent (TE)/g dry weight (DW) and polyphenol content - 20216 mg/100 g DW. For water extraction thyme exhibited the highest ORAC antioxidant activity - 1434 μmol TE/g DW. There was a significant linear correlation between the concentration of total polyphenols and ORAC in the investigated medicinal plants. It can be concluded that the solvent used affects significantly the polyphenol content and the antioxidant activity of the extract and therefore it is recommended to use more than one extraction system for better assessment of the antioxidant activity of natural products. Several of the investigated herbs contain substantial amounts of free radical scavengers and can serve as a potential source of natural antioxidants for medicinal and commercial uses.
Fertilization of plants with silicon is particularly justified in soilless culture in which the roots of plants cannot use silicon resources in the soil. Silicon is the only element that does not harm plants when taken up in excessive amounts and its use in plant fertilization improves the yielding ability of plants and their resistance to various stress factors. The effectiveness of silicon application in growing plants is strictly dependent on both the source of this element, plant species and cultivars. The aim of this study was to determine the effect of root application of colloidal silicon as well as of three types of growing media of different silica content and varying ability to release orthosilicate monomers (rockwool, sand, straw) on yield and chemical composition of greenhouse tomato. The research was conducted in greenhouse in the period 2008–2009. Tomato was grown in an extended growth cycle (22 clusters) using a drip irrigation and fertilization system with closed nutrient solution circulation. Tomato plants fertigated with the nutrient solution enriched with silicon showed significantly higher total fruit yield (15.98 kg·plant-1) compare to plant grown in control treatments. In the studies not found significant differences in total and marketable yield as well as in mean fruit weight between plants grown in rockwool and straw mediums. The total fruit yield of tomato plants grown in sand was lower compared to rockwool-grown plants. The fruit of tomato grown in sand was shown to have more dry matter (5.52%), total sugars (2.58% FR.W.) and potassium (4.19% DW) compared to rockwool culture as well as significantly the highest amount of silicon. The leaves of tomato fertilized with the silicon-enriched nutrient solution contained more silicon as well as less manganese and zinc compared to control plants. Fertilization of plants with silicon is particularly justified in soilless culture in which the roots of plants cannot use silicon resources in the soil. Silicon is the only element that does not harm plants when taken up in excessive amounts and its use in plant fertilization improves the yielding ability of plants and their resistance to various stress factors. The effectiveness of silicon application in growing plants is strictly dependent on both the source of this element, plant species and cultivars. The aim of this study was to determine the effect of root application of colloidal silicon as well as of three types of growing media of different silica content and varying ability to release orthosilicate monomers (rockwool, sand, straw) on yield and chemical composition of greenhouse tomato. The research was conducted in greenhouse in the period 2008–2009. Tomato was grown in an extended growth cycle (22 clusters) using a drip irrigation and fertilization system with closed nutrient solution circulation. Tomato plants fertigated with the nutrient solution enriched with silicon showed significantly higher total fruit yield (15.98 kg·plant-1) compare to plant grown in control treatments. In the studies not found significant differences in total and marketable yield as well as in mean fruit weight between plants grown in rockwool and straw mediums. The total fruit yield of tomato plants grown in sand was lower compared to rockwool-grown plants. The fruit of tomato grown in sand was shown to have more dry matter (5.52%), total sugars (2.58% FR.W.) and potassium (4.19% DW) compared to rockwool culture as well as significantly the highest amount of silicon. The leaves of tomato fertilized with the silicon-enriched nutrient solution contained more silicon as well as less manganese and zinc compared to control plants.
Maize (Zea mays L.) occupies one of the important cereal crops all over the world. It serves as food and oil for human, feed for livestock and as raw material for industry [1], [2]. It is widely grown in various soil and climatic conditions due to its contribution among cereals in the world. It can play a glorious role in economy of the country by feeding malnourished people as well as solving food problems. Therefore, maize should get priority considering the protein malnourishment of the people, because it encompasses more digestible protein than the other cereals [3]. Furthermore, due to the rising poultry industry in Bangladesh, the need for maize is increasing very sharply as maize is an important component of poultry feed. In Bangladesh, total land area and production of maize are 395500 ha and 279500 m tons respectively [4]. The world agriculture faced lots of problems due to soil salinity as its damage the various cellular function of plant. The land is becoming non-productive due to accumulation of salt in fresh soil through tidal flow close proximity to sea level in each year. About 300 million ha of irrigated farmland is estimated to be affected by salinity. Four countries viz. China, India, Pakistan and United States provided more than half of all salt-affected irrigated farmlands in the world [5]. The most severe difficulties for crop production in the dry regions are high concentration of toxic ions especially NaCl either in soil or in irrigation water [6]. Plant growth and productivity drastically restricted by salinity that is of the major environmental factors [7]. The salt stress could be lead to a decrease in the growth and productivity of various crops in the world [8-16]. The disruption of intracellular ionic concentration and osmotic gradients inhibiting a number of vital physiological functions reduced by salinity resulting malfunctioning of plant morpho-physiological characters i.e photosynthesis [17], reduction of protein synthesis and activities of enzyme [18], poor nutritional balance (lowering N, P, K⁺, Ca²⁺ unbalanced carbon metabolism) [19], and stunted stem length, stem width, stempith diameter, leaf blade thickness, leaf vascular bundle length and leaf xylem vessels [20], [21]. Reduction of nutrient uptake capacity often accompanied by mineral toxicity leading to nutritional imbalance [22]. Soil reclamation and/or improved irrigation techniques (generally expensive) could be a systematic tactics for the management of problematic soils/salt affected soil in the arid and semi-arid tropics of this universe. The most inexpensive and more sustainable solution for using these problematic soils is the crop improvement through genetically or agronomical management. So, improvement of new methods to introduce salt stress resistance and tolerance varieties is so important. By cultivating the tolerant genotype that may sustain a reasonable yield on salt affected soil [23]. The germination and tolerance mechanism greatly varied in crop to crop at growth and seedling stage [24]. The selection criterion for screening salt tolerant individual and increasing salt tolerance in many species is the vigorous growth at the seedling stage [25]. Among all of the life cycle of plant, the germination and seedling stage is the sensitive to salinity than the adult stage [26]. The greater reduction of early seedling and growth stage was observed in wheat and sorghum with increasing salinity [27]. Therefore, the present experiment was carried to evaluate salt tolerance of four maize varieties at germination and seedling growth under saline stress environment.
The matter of soil pollution by heavy metals caused to increase of concerns about environment. The present study has been done by the aim of investigation on zinc metal accumulation on cupressus arizonica. To achieving this goal the one-year Cupressus arizonica species seedlings were placed in vases. After the passage of each 55-day time periods from the growth of seedlings, the shoot, root and soil of seedlings were sampled. Results were studied using ANOVA test and Duncan test. The lowest concentration rate of zinc in Cupressus arizonica species organs in the first time period in the shoot and root was 5 g and 1.9 g, respectively and in the second time period in the shoot and root was 2 g and 1.6 g, respectively. Based on the researches, Cupressus arizonica species appropriate for refining zinc metal polluted soils.
To investigate whether the fungicide Azoxystrobin improves the potential to maintain physio-biochemical functions, tomato plants were grown under either well-watered and deficit irrigation conditions. Drought-stressed tomato plants showed significant reductions in cell membrane stability (CMS), relative water content (RWC), relative water loss (RWL) and chlorophylls, growth attributes and leaflet and main stem anatomical features, while exhibited increases in contents of proline and total phenols, activities of catalase (CAT), peroxidase (POD) and polyphenol oxidase (PPO), fresh (FW) and dry (DW) weights of roots, and leaflet spongy tissue thickness compared to well-watered control plants. Under full irrigation, Azoxystrobin treatment significantly increased RWC and chlorophyll content, POD and PPO activities, root DW, number of fruits per plant and many features of leaflet and main stem, while significantly decreased CMS and RWL, root, shoot and plant lengths, shoot and plant FW, and stem xylem tissue thickness compared to the control plants sprayed with water. However, Azoxystrobin treatment ameliorated drought stress in tomato plants and significantly increased CMS and free proline content, activities of CAT, POD and PPO, and contents of free and total phenols, and root DW and number of fruits per plant, in addition to spongy tissue thickness of leaflet, but not affected chlorophylls and carotenoids contents, root FW, plant DW and most of anatomical features compared to the stressed plants without Azoxystrobin treatment. These results support that Azoxystrobin foliar application may have a positive effect on well-watered and drought-stressed tomato plants.
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