Boistimulator effect of stress tolerant rhizobacteria on horticultural models

The tolerant bacteria for abiotic stresses such salinity, drought, and different pH have been used as a good tool to improve plant growth in sustainable agriculture. A pot experiment was conducted to evaluate the potential of isolated stresstolerant bacteria for red mud-polluted soil on growth performance of giant reed plants with increasing concentrations of NaCl 0.0; 0.1; 0.2; 0.3; 0.5; 1.0% under gnotobiotic conditions. At the same time biostimulator potential of isolated bacteria was observed in case of radish in vitro germination experiment under salt stress. It was found that the observed bacterial strain can tolerate the salt and pH moderately however it is resistant against hydrogen-peroxide caused oxidative stress in high concentration (up to 2640 mM). Molecular identification, basis on 16S rDNA showed 98% similarity to the Bacillus aryabhattai bacterial strain. The isolated strain alleviated the negative effect of salt (0.05%) for the radish seed germination. However in higher salt concentration (≥0.1%) the bacterial mitigating effect vanished. The inhibition of increasing salt concentration for giant reed plantlets was also alleviated by halotolerant bacteria treatment (≥0.5%)

Significance of nutrient and water sustainability: Effect of land leveling, cut off irrigation and N- fertilization on maize yield

A wide variety of soil, nutrient, and irrigation management practices are available to farmers, most of them concerned with the basic building block of agriculture, the soil. Soil management practices include the tillage and cropping systems and crop rotations used on a farm. Therefore, sustainable crop production should be managed to enhance soil ecosystems, improving soil health and fertility and reversing degradation and pollution of land. As well as, it should be contributed to maintaining and improving, and efficiently utilizing, water resources (quantity, access, stability and quality), especially promoting practices that minimize risks of water pollution from agrochemicals and save water. It is well documented that fertilizer N is the most costly input in maize production and its effective management is a major challenge for improving productivity and environmental sustainability. In present study, the effect of land leveling, cut off irrigation and N- fertilizer on yield and yield components of maize have been studied. The results showed that the highest yield of grain and straw of maize was obtained with using N-fertilization rate 288 kg N ha-1, land levelling rate 0.01 % of surface slope and cut off stream of irrigation rate 75%. The results of this study suggest that, irrigation application efficiency (%) increased from 71 % (for control) to 80 % for cut off 75 % of stream irrigation and land leveling with 0.01 % slope. Thus, about 20 % from the applied water for irrigation is saved by the previous treatments

In vitro comparative study of two Arundo donax L. ecotypes’ selenium tolerance

Selenium tolerance of two somatic embryo-derived Arundo donax L. ecotypes (Blossom, 20SZ) were compared in in vitro culture. Sodium-selenate (1 – 100 mg L-1) as known the most phytoavailable selenium form and the less studied red elemental nanoselenium (100 mg L-1) were applied as selenium treatments. Basis on the results Blossom ecotype seemed to be more sensitive to the sodium-selenate than 20SZ. Inhibiting effect of selenate was effectuated above 10 mg L-1 in case of Blossom, which was manifested in decreased survival rate and growing parameters. Contrast to this 20SZ could tolerate the selenate ≤ 20 mg L-1 without any toxic symptoms. Lower selenate tolerance of Blossom could be explained with higher selenium accumulation. Both of two ecotypes could also uptake and accumulate the red elemental nanoselenium however in much less extent compared to selenate

Advances in Understanding Environmental Risks of Red Mud After the Ajka Spill, Hungary

In the 5 years since the 2010 Ajka red mud spill (Hungary), there have been 46 scientific studies assessing the key risks and impacts associated with the largest single release of bauxite-processing residue (red mud) to the environment. These studies have provided insight into the main environmental concerns, as well as the effectiveness of remedial efforts that can inform future management of red mud elsewhere. The key immediate risks after the spill were associated with the highly caustic nature of the red mud slurry and fine particle size, which once desiccated, could generate fugitive dust. Studies on affected populations showed no major hazards identified beyond caustic exposure, while red mud dust risks were considered equal to or lesser than those provided by urban dusts of similar particle size distribution. The longer-term environmental risks were related to the saline nature of the spill material (salinization of inundated soils) and the release and the potential cycling of oxyanion-forming metals and metalloids (e.g., Al, As, Cr, Mo, and V) in the soil–water environment. Of these, those that are soluble at high pH, inefficiently removed from solution during dilution and likely to be exchangeable at ambient pH are of chief concern (e.g., Mo and V). Various ecotoxicological studies have identified negative impacts of red mud-amended soils and sediments at high volumes (typically [5 %) on different test organisms, with some evidence of molecularlevel impacts at high dose (e.g., genotoxic effects on plants and mice). These data provide a valuable database to inform future toxicological studies for red mud. However, extensive management efforts in the aftermath of the spill greatly limited these exposure risks through leachate neutralization and red mud recovery from the affected land. Monitoring of affected soils, stream sediments, waters and aquatic biota (fungi, invertebrates and fish) have all shown a very rapid recovery toward prespill conditions. The accident also prompted research that has also highlighted potential benefits of red mud use for critical raw material recovery (e.g., Ga, Co, V, rare earths, inform), carbon sequestration, biofuel crop production, and use as a soil ameliorant

In vitro regeneration of parsley and coriander plants: uptake, translocation and accumulation of nicotine

It is well known that, nicotine is a type of alkaloids found in some plants of family Solanaceae but some other plants can produce it under different stresses. Medicinal and spice plants cannot synthesize nicotine under normal growth conditions as well as the fate and behavior of nicotine in plant tissues are not understood totally. Many medicinal plants and plant derived products as spices may be contaminated by nicotine from different sources. This contamination could be considered the main problem facing the exportation of these plant products. On the other hand, determining of nicotine putative sources and detecting its uptake from nicotine contaminated soils and tobacco smoke using peppermint plants have been already studied under greenhouse conditions in Germany. These results from pot experiments demonstrated that, peppermint had the ability to uptake and metabolize nicotine endogenously. So, some plants including parsley and coriander were selected to investigate the nicotine uptake mechanism from culture media supplemented with different nicotine concentrations, which extracted from cigarette tobacco (Matosian Egyptian Spirit) comparing with nicotinic acid (as a pure chemical of nicotine) in Egypt. Moreover, this in vitro study aimed to focus on the translocation and accumulation of nicotine in plant tissues. Hence, in virto research has been already begun using parsley and coriander plants. The preliminary results indicated that, regenerated plants of parsley and coriander were successfully obtained on MS medium supplemented with 1 mg L-1 benzyl adenine + 0.01 mg L-1 naphthalene acetic acid. Furthermore, callus cultures have been initiated on MS medium fortified with 1 mg L-1 benzyl adenine + 1 mg L-1 naphthalene acetic acid. Regenerated plants and obtained callus of these plants will be transferred onto MS media supplemented with different concentrations of nicotine and nicotinic acid as mentioned above. In parallel, some field experiments in Egypt have been conducted to get a holistic overview for the object under investigation. Therefore, different experiments including field, pots and in vitro experiments have been conducted in order to reduce the contamination of plants with nicotine

Ecotoxicology of Copper in Horticultural Soils: A Review

Nowadays, the world is facing the problem of environmental pollution because of the increase of man’s needs requires development in life activities, progress industrialization, transportation tools, enhancement of agriculture and exploitation of natural resources. Soil and water resources are extremely exposed to pollution from different aspects. Agrochemicals in particular, have created severe problems, since they release thousands of chemicals to the environment. Several studies on the effect of environmental pollutants on agroecosystem have been carried out. On the other hand, the importance of trace elements as environmental pollutants is well known and well documented in literature. Cu contamination to agricultural soils has been accelerated due to its wide and repeated use in agriculture and horticulture as fertilizers or fungicides to protect vines, citrus trees, and other fruit crops against fungus diseases. Applied Cu from different agrochemical sources to agroenvironment may be adsorbed and are transported to the groundwater table and pollute it besides polluting the soils. The use of Cu-based fungicides in vineyard soils is widely documented worldwide. It has been found that many countries contain concentrations in excess of 100 mg kg−1. Importance of study of transport of Cu arises due to the fact that Cu is absorbed in soils and also reaches the groundwater table, thus polluting both soil and ground water. It is often more important to be able to estimate the mobile fraction, the readily soluble fraction, the exchangeable fraction, or the plant available fraction of Cu content of a soil as a more direct indication of the likelihood of deleterious or toxic effects on soils and groundwater. Therefore, the aim of present work was to highlight the behavior and ecotoxicological effects of copper on horticultural soils

Foliar Nutrition and Post-Harvest of Onion Seed: Effects of storage temperatures, storage period and foliar nutrition

The aim of onion bulb storage is to meet consumer demand for extended availability of onions whilst maintaining product quality. The principal biological factors leading to onion bulb deterioration are respiration, resumption of growth and pathogen attack. In onion bulbs a dormant period, when sprouting and rooting cannot be induced, is followed by a period of internal changes that prepare the bulb for breaking of dormancy and subsequent growth. Out of storage, the bulb then proceeds towards flowering and seed production. Two successive winter seasons of 2008/2009 and 2009/2010 were conducted under sandy soil conditions to study the effect of spraying with 12 commercial compounds on yield and yield components of onion seeds and storage The seed yield of each commercial compounds plot from previous experiment was divided into two groups, storage under room temperature and 5°C. Seeds transferred immediately after drying to Increasing Export Competition of Some Vegetable Crops Project Laboratory located in Faculty of Agriculture, Cairo University. The effects of storage temperature, storage period and foliar with some commercial compounds on onion seed quality were considered. Storage in 5°C had the higher germination percentage than storage in room temperature. Results indicated that as storage period increased the germination percent decreased. The treatment with boron or amica in the first season had the highest germination percentage. While, the treatment with union Zn, union feer, union Mn, boron, elga 600, caboron, amica, hummer or amino X had the highest germination percentage in the second season. Storage in 5°C resulted in higher moisture content than storage in room temperature. Regarding the effect of storage period on moisture content, the water content was significantly increased with prolongation of storage period. The lowest values of water content were recorded for treatments with union feer, shams K or boron in the first season, and union feer, shams K, boron, magnesium, shetocare or hummer in the second one. Catalase activity was significantly decreased as storage period increased. The treatment with shams K, boron, shetocare or amino X had the highest catalase activity in both seasons. Peroxidase activity was significantly decreased as storage period increased. Foliar application with boron had the highest peroxidase activity in both seasons. Seed stored in room temperature had the higher malondialdehyde content than those stored in 5°C in the second season. The malondialdehyde content increased as storage period increased. The treatment with magnesium, caboron and the control in the first season, and the treatment with magnesium and the control in the second season had the highest malondialdehyde content