Maize growth and yield as affected by wheat residues and irrigation management in a no-tillage system

Determining the proper rate of wheat residues incorporation into the soil under a wheat–maize double cropping system is an important issue in southern parts of Iran, where these two irrigated crops are consecutively grown. A 2-year experiment (2010–2011) was conducted to evaluate the effect of wheat residue incorporation rates (25%, 50% and 75%) and irrigation intervals (12, 16 and 20 days) on yield and growth of maize under no-tillage system compared to control without residue and under conventional tillage (CT) at the College of Agriculture, Shiraz University, Shiraz, Iran. The experiment was conducted as a split plot arranged in randomized complete block design with three replications. The results showed that increased irrigation intervals reduced the plant height (14.6%), leaf-area index (12.9%), rows (10.1%) and grains per ear (29.8%), thousand grain weight (6.9%), grain (33.8%) and biological yield (24.2) and harvest index (23.2%). Water deficit had no significant effect on soil organic matter and carbon-to-nitrogen ratio. Under 12 and 20 days irrigation intervals, the highest grain yields were obtained with 12.7 and 8.6 t ha^?1 in CT and 25% residue incorporation into soil, respectively. Therefore, according to the results of this 2-year study, realized incorporation of 25% wheat residue soil covering percentage is recommended for this area with limited water resources.     

Evapotranspiration model selection for estimation of actual evaporation from bare soil,as required in annual potential groundwater recharge studies of a semi-arid foothill region

Improved evapotranspiration estimation is instrumental in annual potential recharge (Re) evaluations of semi-arid regions, in the context of the water balance approach. Complementary relationship areal evapotranspiration (CRAE) and advection–aridity (AA) and a general combination equation proposed by Granger and Gray (GG) were evaluated for the estimation of actual evaporation (E_a) from bare soil under occurrence of Re. Model capability was evaluated by utilizing data from lysimeter measurements during the hydrological years [(2011–2012) and (2012–2013)]. Measured parameters included soil moisture (SM), rainfall and related meteorological data and Re (lysimeter output). All models with original parameters performed poorly during 2011–2012 and 2012–2013, underestimating annual Re values. The 2011–2012 data were used for model calibration, considering annual E_a [criterion (I)] and cumulative E_a during the occurrence period of Re [criterion(II)]. The calibrated CRAE model [criterion (II)] produced the best simulation for E_a (NRMSE < 30%). The 2012–2013 data were used to validate the models, and the calibrated CRAE model produced acceptable results (NRMSE < 10%) in SM simulation (both criteria). But calibrated CRAE under criterion (II) provided the best estimation of annual Re (ΔQ < 6%). According to the results, CR models can produce acceptable estimation of annual Re, if initially calibrated utilizing criterion (II).     

EFFECTS OF CALCIUM/MAGNESIUM QUOTIENTS AND NICKEL IN THE GROWTH MEDIUM ON GROWTH AND NICKEL ACCUMULATION IN PISTACIA ATLANTICA

We selected two serpentine (ultramafic) and non-serpentine populations of P. atlantica and a cultivar of P. vera cv. ‘Badami’, to compare their responses to two growth limiting factors of serpentine soils: low calcium (Ca)/ magnesium (Mg) quotients and high concentrations of nickel (Ni). A solution culture system using perlite as a neutral substrate was used for growing the plants. Growth and elemental composition of plants then were analyzed. All populations/species proved to be excluders of Ni but, interestingly the excluding ability of P. vera to prevent translocation of Ni from root to shoot was higher than that of both populations of P. atlantica. The plants of serpentine population of P. atlantica were more resistant to lower Ca/Mg quotients and higher concentrations of Ni. We suggest that the growth and exclusion responses of the tested plants to Ca/Mg quotients and Ni result from adaptations to their natural substrates, ultramafic or saline soils.     

Influence of Salinity on Chlorophyll,Leaf Water Potential,Total Soluble Sugars,and Mineral Nutrients in Two Young Olive Cultivars

The effect of salinity (NaCl) on chlorophyll, leaf water potential, total soluble sugars, and mineral nutrients in two young Iranian commercial olive cultivars (‘Zard’ and ‘Roghani’) was studied. One-year-old trees of these cultivars were planted in 10-L plastic pots containing equal ratio of sand-perlite mixture (1:1). Sodium chloride at concentrations of 0, 40, 80, 120, or 160 mM plus Hoagland's solution were applied to these pots for 150 days. The results showed that chlorophylls (a), (b), and (a+b) reduced with increasing of salinity up to 40 mM. There was no difference between cultivars for chlorophylls (b) and (a+b) while ‘Roghani’ showed more decreased in content of chlorophyll (a) than did ‘Zard’. Total soluble sugars in leaves increased with an increase in salinity up to 80 mM but decreased with additional increase in salinity. Salinity stress reduced water potential equally in both cultivars. The concentrations of sodium (Na) and chloride (Cl) and Na/potassium (K) ratio were increased and K decreased with increasing of salinity up to 80 mM in leaves and roots. Concentrations of K, magnesium (Mg), calcium (Ca), phosphorus (P), and nitrogen (N) reduced significantly in leaves, shoots and roots with increasing salinity.     

Phenotypic diversity and relationships of fruit quality traits in inter-specific almond × peach backcrosses breeding progenies

Nineteen agrochemical traits of 20 almond inter-specific backcrosses progenies were evaluated and compared for three consequence years to find out their phenotypic diversity and determine the relationships of fruit quality traits in almond × peach backcrosses breeding progenies. The variation was observed for traits of phenology parameters (blooming time, ripening time), Physical parameters (fruit weight, width, height, shape, thickness, skin pubescences, colour and flower type), chemical parameters (total sugar content, soluble solids content and acidity) and sensory parameters (attractiveness, taste, and flavor) and yield. Many fruit characteristics that are important to breeders are present in this collection. A high variability was found in the evaluated almond progenies and significant differences were found among them in all studied quality attributes. Year-by-year variations were observed for majority of traits. A significant correlation was found among the fruit height, fruit width, skin pubescences and yield. Fruit height showed a significant positive correlation with fruit weight and fruit thickness and some other traits and a negative correlation with the titratable acidity, skin pubescences and fruit flavour. A high negative correlation was found between the fruit weight and titratable acidity (?0.8). Low coefficients were got between the flower colour and skin pubescences. In addition, principal component analysis it possible to established similar groups of genotypes depending on their quality characteristics and to study relationships among pomological traits in almond progenies evaluated.     

Leaf macro- and micro-morphological altitudinal variability of Carpinus betulus in the Hyrcanian forest (Iran)

We investigated the altitudinal variation of Carpinus betulus L. in the Hyrcanian forest using leaf macro-morphological and micro-morphological traits. We collected a total of 1600 leaves from two locations. In each location, we sampled six populations along an altitudinal gradient ranging from 100 m to 1,150 m. We found that trees in the higher elevations have smaller leaf lamina than those in the lower elevations. In contrast, leaf mass per area was high at low altitudes and increased newly at the higher ones. Stomatal dimension was negatively correlated with elevation, while stomatal density was positively correlated with elevation. We also found that two transects showed the same plasticity trend. Leaf area showed the highest plasticity, while the number of veins showed the lowest plasticity. This study shows that altitude, and related temperature and rainfall, represents an important driving force in Carpinus betulus leaf morphological variation. Moreover, our results suggest that leaf area, leaf mass per area and stomatal density could influence the species responses to different ecological conditions.     

Runoff and sediment concentration of different parts of a road in Hyrcanian forests

Road prisms, such as cutslopes, fillslopes and road surfaces, can be important contributors of sediment to streams in forested watersheds. In this study rainfall simulations were carried out on cutslopes, fillslopes, road surfaces and forest grounds in hardwood forests of Lolet and Lat Talar, Iran. Water at intensity of 32.4 mm·h 1 was sprayed from a nozzle onto a square area of 0.48 m 2 . Runoff was collected by water gauge every 4 min and then runoff and sediment parameters were measured in each plot. Results indicated that on road surfaces, the runoff coefficient was 63.28%. On the cutslopes and fillslopes, the runoff coefficients were 35.14% and 10.23%, respectively. On the forest ground as a control, the runoff coefficient was 5.90%. Runoff volume was 2.73 mL·s-1 on the road surfaces and 1.52 mL·s-1 on cutslopes. On fillslopes the runoff volume was 0.44 mL·s-1 and on the forest ground 0.25 mL·s-1 . The greatest rate of soil loss was found on the cutslope (280.79 g·m-2·h-1). The total soil loss from the cutslopes was two times higher than that from the road surfaces and six times higher than that from the fillslopes. We conclude that cutslopes can be considered the main source of sediments in our study sites, but the function of road surface as a source of runoff generation is more important.     

Antiemetic efficacy of promethazine on xylazine-induced emesis in cats

The prophylactic antiemetic effect of 3 dosages of promethazine injected into cats 1 h before administration of xylazine was compared with that of a saline solution. Prior treatment with 2 and 4 mg/kg of promethazine significantly reduced the frequency of emetic episodes. Promethazine may be used as a prophylactic antiemetic in cats treated with xylazine.     

Evolutionary characterization of hemagglutinin gene of H9N2 influenza viruses isolated from Asia

The full length hemagglutinin (HA) genes of 287 H9N2 AI strains isolated from chickens in Asia during the period 1994-2009 were genetically analyzed. Phylogenetic analysis showed that G1-like viruses circulated in the Middle East and Indian sub-continent countries, whereas other sublineages existed in Far East countries. It also revealed G1-like viruses with an average 96.7% identity clustered into two subgroups largely based on their time of isolation. The Ka/Ks ratio was calculated 0.34 for subgroup 1 and 0.57 for subgroup 2 indicates purifying/stabilizing selection, but despite this there is evidence of localized positive selection when comparing the subgroups 1 and 2 protein sequences. Five sites in HA H9N2 viruses had a posterior probability >0.5 using the Bayesian method, indicating these sites were under positive selection. These sites were found to be associated with the globular head region of HA. To identify sites under positive selection; amino acid substitution classified depends on their radicalism and neutrality. The results indicate that, although most positions in HAs were under purifying selection and can be eliminated, a few positions located in the antigenic regions and receptor binding sites were subject to positive selection.     

Partial replacement of fishmeal with corn protein concentrate in diets for rainbow trout (Oncorhynchus mykiss): Effects on growth performance,physiometabolic responses,and fillet quality

An 8‐week feeding trial was run to investigate the replacement of fishmeal with corn protein concentrate (CPC; Empyreal^®) in rainbow trou (100.5 ± 2.3 g) diet. Fishmeal was increasingly replaced with 0 (Control), 30 (CPC₃), 60 (CPC₆), 90 (CPC₉) and 120 (CPC₁₂) g/kg CPC. The results showed that the substitution of fishmeal with CPC up to 90 g/kg did not cause significant differences in the growth indices as compared to the control group, while further replacement resulted in the reduction of the growth performance. The fillet crude protein showed no significant difference between the control diet and diets containing up to 90 g/kg CPC (p > .05). Serum biochemical parameters such as albumin and glucose did not change notably, while the highest levels of alanine aminotransferase and lactate dehydrogenase were seen in the CPC₁₂ group (p < .05). Also, serum lysozyme activity was increased with the elevation of dietary CPC up to 90 g/kg (p < .05). The redness and yellowness of the fillet were markedly elevated with the dietary incorporation of CPC (p < .05). Taken together, the optimum range of fishmeal substitution with CPC was 81.0–82.2 g/kg CPC in rainbow diet based on the broken‐line regression analysis.