Assaying the allelopathic effects of <Emphasis Type="Italic">Eucalyptus camaldulensis</Emphasis> in a nursery bed incorporated with leaf litter

Allelopathic effects of Eucalyptus camaldulensis Dehnh. were confirmed in Petri dish and pot experiments in our previous studies. However, the degree to which such effects under controlled experiments exist in more complex ecological settings remains to be tested. Thus, the present study was carried out by incorporating different proportions of ground litter of E. camaldulensis in soil. The growth of three agricultural crops: falen (Vigna unguiculata (L.) Walp.), chickpea (Cicer arietinum L.), and arhor (Cajanus cajan (L.) Millsp.), and two tree species, kala koroi (Albizia procera (Roxb.) Benth.) and ipil ipil (Leucaena leucocephala (Lam.) de Wit) were tested. There were inhibitory effects of leaf litter on germination, shoot and root growth, leaf number, and collar diameter as well as a reduction of nodulation by legume crops (25–80% reduction). The extent of the effects was dependent on the proportion of leaf litter, the species and the type of traits. In contrast to shoot growth, the effect on root growth was more severe. No effect on germination was found with the agriculture crops while the two tree species showed reduced germination. The effect was greater in the presence of higher proportions of leaf litter mixed in soil while in some cases lower proportions stimulated growth. Not all species were suppressed; A. procera, C. cajan, V. unguiculata showed compatible growth while C. arietinum and L. leucocephala were found incompatible. This study provides evidence that E. camaldulensis has allelopathic potential under field conditions and a careful selection of associated crops in agroforestry systems is highly recommended.     

Importance of transitional leaf states in canopy rainfall partitioning dynamics

The temporal dynamics of forest canopy rainfall partitioning are important to forest ecology and management as it influences all subsequent hydrological processes along the rainfall-to-discharge flow path. Despite a growing body of literature on the importance of coupled hydrological–ecological interactions during periodic forest life cycle events, little work has examined how canopy rainfall partitioning varies across transitional leaf states (between the leafed vs. leafless states). This study analyzed a 3 year field monitoring campaign for two tree species in semiarid Iran (Robinia pseudoacacia and Platanus orientalis) to describe rainfall partitioning dynamics across the full-leaf, senescence, leafless, and leafing states. Crown saturation point, canopy storage capacity, free throughfall coefficient and the ratio of wet canopy evaporation rate to mean rainfall intensity were related to decreases/increases in plant area index and canopy closure. The high variability of rainfall partitioning observed in this study highlights the importance of transitional leaf states in the temporal characterization of water inputs to forest surfaces and boundary layer.     

Effect of Fe-Glycine Aminochelate on Pod Quality and Iron Concentrations of Bean (Phaseolus vulgaris L.) Under Lime Soil Conditions

Iron (Fe) has very low solubility and plant availability in calcareous soils, and this generally results in restricted plant production and low quality. During last decades, various commercial chelated fertilizers have been used in agricultural systems to meet iron requirements of crops. However, despite extensive application of these commercial chelate fertilizers, there is real doubt and high concerns regarding many aspects of their action, dynamics, efficiency, and safety in plant-soil–environment systems. In the present study, growth and quality of green bean plants (Phaseolus vulgaris L.) were evaluated under foliar and soil applications of Fe-glycine chelate (iron glycine aminochelate) and commercial Fe-EDDHA chelate in a lime soil. The results showed that morphophysiological parameters were improved by the application of Fe-glycine and Fe-EDDHA treatments. Foliar application of Fe-glycine has significantly improved leaf area and Soil-Plant Analyses Development (SPAD) values compared to control and Fe-EDDHA treatments. Pod yield, shoot (but not root) dry weight, and iron concentrations in leaves and pods (but not in root) were significantly higher when plants were treated by Fe-glycine rather than Fe-EDDHA in both soil and foliar applications. Vitamin C and protein contents were significantly improved and phenolic compounds were reduced by foliar application of Fe-glycine and soil application of Fe-EDDHA. The results indicate that foliar application of Fe-glycine can significantly increase Fe concentrations and quality of beans under lime soils with restricted iron availability.     

Preparation of Modified Magnetic Cobalt Nanoparticles as a New Magnetic Sorbent for the Preconcentration and Determination of Trace Amounts of Lead Ions in Environmental Water and Soil (Air-Dust) Samples

In this study, cobalt magnetic nanoparticles (MNPs) were synthesized and then modified by sodium dodecyl sulfate (SDS) and 2-(5-bromo-2-pyridylazo)-5-diethyl aminophenol ligand (5-Br-PADAP), through a chemical precipitation method. Characterization of the prepared MNP adsorbents was performed by Fourier transform infrared and transmission electron microscopy. Cobalt nanoparticles (NPs) surface modified with SDS and 5-Br-PADAP was evaluated as a nanoparticulate solid-phase extraction (SPE) absorbent for lead ions Pb(II) from water and standard samples, prior to its flame atomic absorption spectrometry determination. Effects of pH, amount of sorbent, desorption solvent, adsorption time, desorption time, and interfering ion concentration on extraction efficiency were investigated. Under optimal conditions, the calibration curve was linear in the range of 1.0–500 ng mL^?1of Pb(II) with R² = 0.998. Detection limit was 1.6 ng mL^?1 in the original solution (3S_b/m), and the relative standard deviation for replicate determination of 0.5 μg mL^?1 Pb(II) was ±2.7%.     

Interactive effects of saline irrigation water and genotypes on nutrient composition of chamomile (Matricaria Recutita L.)

This study was conducted to elucidate the effect of salinity (2, 6, 9, and 12 dS m^?1 sodium chloride (NaCl)) on three Iranian German chamomile genotypes (Shiraz, Ahvaz, and Isfahan). The Shiraz and Ahvaz genotypes, respectively, had the highest productivity and tolerance level, while the Isfahan was the less salt-tolerant genotype. In contrast to quantitative traits, the Isfahan genotype exhibited superior qualitative traits in terms of essential oil and chamazulene percentage. The differential responses to productivity and salt-resistance were attributed to the genetic variation, higher root to shoot ratios, and compartmentalization of sodium in roots of the Shiraz and Ahvaz genotypes, leading to better nutrient uptake and balance. While the nutrient composition was relatively in the same range for all genotypes, the higher accumulation of phosphorus in root and anthodia of the Shiraz genotype was evident. In addition, anthodia of the Ahvaz and root of the Shiraz genotype stored more nitrogen nutrient element.     

Effect of Nanoclinoptilolite/Nanohydroxyapatite mixtures on phosphorus solubility in soil

Phosphorus (P) is a vital element for plant growth and maturity, yet most soils have low P availability. The aim of the present study was to synthesize a mixture of nanohydroxyapatite (nHA) and saturated nanoclinoptilolite (nCp) and compare its ability to improve the P solubility with that of a natural system (Cp/rock phosphate). Consequently, as nCp were saturated with different salt solutions, the P solution concentration decreased in the following order: ((NH₄)₂SO₄) NH₄–nCp > (NH₄Cl) NH₄–nCp > (KCl) K–nCp > (K₂SO₄) K–nCp. Higher P availability was achieved at higher ratios of nCp/nHA. The nCp/nHA appear twice more effective in P released than Cp/PR (42.73% vs 19.23%). The greatest increase (5 mg/L) in the quantity of P released was at a nCp/nHA ratio of 15. Parabolic diffusion and power function equations fitted best to the data. This work demonstrates that nCp/nHA can act as an effective P fertilizer in calcareous soils.     

Distribution of Cr,Ni and Co in soils and rocks of Neyriz area (Iran): the influence of ophiolitic formations

Neyriz area, on south of Neyriz ophiolite complex, is one of the most important areas in fruit production. However, no study has been yet performed to assess the contamination status of soils in this region. The objective of the present study was to explore soil pollution by Cr, Ni and Co. Three landforms (ophiolite hills, alluvial fan and playa) were selected along a transect. Seven pedons were excavated and soil and rock samples were obtained. The total concentration of Cr, Ni and Co, Enrichment Factor (EF) and Geo-accumulation index (I_geo) were determined. Results showed that soils over ophiolite hills and alluvial fan were extremely polluted by Cr and Ni (I_geo=3–6). The EF Index confirmed that heavy metals originated from ophiolite rocks in the region. Both indices showed a descending trend from ophiolite hills to playa that related to deposit transportation processes during landforms evolution. It was also observed a decreasing vertical trend in metal contents in the soils over alluvial fan which can be attributed to the long-time irrigation and plant uptake as affected by land use. Further investigation is needed to understand the contamination status of ground-water and orchards of the region to achieve sustainable management.     

Growth performance,survival, body composition,hematological parameters,intestinal histomorphology,and digestive enzymes’ activity in juvenile rainbow trout (Oncorhynchus mykiss) fed dietary Immunogen®

The aim of present study was to evaluate the effects of dietary Immunogen® supplementation on juvenile rainbow trout, where 120 fish (81.7 ± 2.23 g) were fed diets supplemented with either 0.0 (control) or 2 g Immunogen® kg^?1 for 7 weeks. The fish fed the Immunogen®-supplemented diet showed an improvement in growth performance, feed utilization, and protein efficiency ratio and a decrease in feed conversion ratio. The fish fed the Immunogen®-supplemented diet showed higher body protein content. There were no significant differences in red blood cell count, eosinophil, or lymphocyte between the treatments. However, white blood cells, neutrophil, and monocyte were higher in the fish fed fish with the Immunogen®-supplemented diet. Supplementation of Immunogen® has increased villi height and tunica muscularis thickness as well as gut protease and lipase activities. The present study revealed that supplementation of Immunogen® can improve intestinal morphology and increase digestive enzyme activity and consequently increase trout growth and feed efficiency.     

<Emphasis Type="Italic">Bacillus</Emphasis> species as the most promising bacterial biocontrol agents in rhizosphere and endorhiza of plants grown in rotation with each other

In this study, a total of 550 cultivable bacterial isolates were isolated from rhizosphere and endorhiza of rice, Berseem clover, and oilseed rape grown in rotation with each other. The potential of antifungal activity of all isolates against five rice pathogenic fungi was investigated under in vitro conditions. Of 550 isolates, 139 inhibited the mycelial growth of at least one fungal rice pathogen. The results also showed that rhizosphere and endorhiza of every third plant (three studied plants) harbored the bacteria (139 isolates) with good potential for inhibiting fungal rice pathogens in vitro. Based on biochemical tests and by comparison of 16S rDNA sequences, of the superiors six endophytic and rhizosphere isolates, which showed strong inhibitory effects against the mycelial growth of all the five fungal rice pathogens (Magnaporthe oryzae, M. salvinii, Fusarium verticillioides, F. fujikuroi, and F. proliferum), were identified. Two isolates REN₄ and CEN₂, isolate CEN₆, isolate CEN₃, and two isolates REN₃ and CEN₅ were closely related to Bacillus mojavensis, B. amyloliquefaciens, B. subtilis, and B. cereus respectively. Strains REN₄ and REN₃ were obtained from rhizosphere and endorhiza of rice, while strains CEN₆ and CEN₂, and strains CEN₅ and CEN₃ were isolated from rhizosphere and endorhiza of clover and oilseed rape respectively. Therefore, it can be concluded that plants cultivated in rotation with rice and grown on the same soil harbor protective bacteria such as genus Bacillus and that may be potential reservoirs of bio-control agents for control of the rice pathogenic fungi tested in this study.