Comparison of various weed control programs for potatoes

All weed control programs resulted in satisfactory weed control. Costs of controlling weeds ranged from $10 to $93/ha. Cultivation alone was the cheapest method of controlling weeds. Controlling weeds by using herbicides alone with no cultivation resulted in the highest weed control costs but tended to give the best weed control at harvest. Herbicides saved one to two cultivations. EPTC (S-ethyl dipropylthiocarbamate) gave slightly better control of green foxtail [Setaria viridis (L.) Beauv.] and slightly poorer control of broadleaf weeds than trifluralin (α,α,α,-trifluoro-2,6-dinitro-N, N-dipropyl-p-toluidine). Cultivation helped control weeds but had no other apparent beneficial or adverse effect on potatoes. The correlation coefficient between total tuber yield and dry weight of weeds was ?0.97 at Grand Forks, North Dakota and ?0.85 at Casselton, North Dakota.     

Phosphorus Fractionation Affected by Root Induced Changes of Two Canola Cultivars

Eurasian Soil Science - In order to study the root-induced changes on behavior of phosphorus in the rhizosphere of two canola cultivars in order to better management of P fertilization this...     

Mechanical properties and in vitro degradation of PLGA suture manufactured via electrospinning

The current research discusses the efforts to achieve a Poly(lactide-co-glycolide)(PLGA) nanofiber yarn using two differently charged nozzles with potential application as surgery suture. First, electrospinning parameters such as solution concentration, applied voltage, feed rate were optimized to produce yarn with smooth nanofibers. In order to improve the properties of produced suture, heat setting setup was developed. Two heat setting techniques, including hot water and dry heat were applied, and the influence of the heat setting process on the mechanical properties of yarn was studied. The results showed that heat setting with boiling water was the best method. At first strength, E-modulus and extension of prepared suture were 36.6 MPa, 0.9 GPa and 68.8 % respectively. After improvement with heat setting, strength and E-modulus increased to 63.7 MPa, 2.7 GPa respectively and extension decreased to 29.7 %. Finally, in order to analyze knot performance, two types of surgical knot (square and surgeon) were used, and mechanical properties were investigated. The presence of knot lessens mechanical properties for each two type. Square knot showed better mechanical properties than surgeon’s knot. With square knot strength, E-modulus and extension were 62.1 MPa, 2.1 GPa, 28.6 %, respectively. In vitro study of nanofiber yarn degradation behavior showed that the mechanical properties were decreased. This could be due to greater surface area of nanofibers exposed to surrounding environment.     

Indirect Organogenesis through Seedling-Derived Leaf Segments of <Emphasis Type="Italic">Ficus Religiosa</Emphasis> - a Multipurpose Woody Medicinal Plant

The aim of this study is to introduce the suitable protocol for indirect regeneration from seedling-derived leaf segment of Ficus religiosa. The leaf explant successfully produced callus on MS medium containing various concentrations of auxin in combination with BAP. The maximum callus induction (100%) was achieved in MS medium containing 0.5 mg/l 2,4-D plus 0.05 mg/l BAP and MS medium containing 1.5 mg/l NAA plus 0.15 mg/l BAP as well. MS medium consisting of 2,4-D produced yellow-brownish and friable callus (type I) while the yellowish and compact calli (type II) were obtained in MS medium consisting of NAA. On the other hand, MS medium supplemented with IBA formed greenish and compact calli (type Ш). The regeneration rate in type II callus was less than the type I, and there was no shoot induction observed on type Ш calli. MS medium supplemented with 1.5 mg/l BAP in combination with 0.15 mg/l IBA had the highest regeneration frequency (100%) and maximum shoot numbers (5.16) as well as shoot length (2.56 cm) in type I callus. A maximum of 93.33% root induction was observed in MS medium supplemented with 2.0 mg/l IBA plus 0.1mg/l NAA. The plantlets were successfully transferred to the greenhouse. This system could be utilized for large-scale multiplication of Ficus religiosa.     

Modelling the spatial distribution of snake species in northwestern Tunisia using maximum entropy(Maxent) and Geographic Information System(GIS)

We used GIS and maximum entropy to predict the potential distribution of six snake species belong to three families in Kroumiria(Northwestern Tunisia): Natricidae(Natrix maura and Natrix astreptophora), Colubridae(Hemorrhois hippocrepis, Coronella girondica and Macroprotodon mauritanicus), and Lamprophiidae(Malpolon insignitus). The suitable habitat for each species was modelled using the maximum entropy algorithm, combining presence field data(collected during 16 years:2000–2015) with a set of seven environmental variables(mean annual precipitation, elevation, slope gradient,aspect, distance to watercourses, land surface temperature and normalized Differential Vegetation Index. The relative importance of these environmental variables was evaluated by jackknife tests and the predictive power of our models was assessed using the area under the receiver operating characteristic. The main explicative variables of the species distribution were distance from streams and elevation, with contributions ranging from 60 to 77 and from 10 to 25%,respectively. Our study provided the first habitat suitability models for snakes in Kroumiria and this information can be used by conservation biologists and land managers concerned with preserving snakes in Kroumiria.     

Differential Response to Salt Stress Within and Among Iranian Melilotus Species

This paper explores the salt-tolerance response of Melilotus species, a forage legume, based on tolerance/susceptibility indices, leaf water relations, leaf/root ion concentrations and multivariate (factor and function discriminate) analyses. In a greenhouse experiment, salinity-susceptibility of 12 accessions of Melilotus (M. albus, M. indicus, M. officinalis) in addition, two controls (alfalfa and Persian clover) were evaluated at 0 mM, 100 mM, 200 mM, and 300 mM of sodium chloride (NaCl). The experiment was conducted in a split plot design with two replications. Stress tolerance score (STS) was calculated based on tolerance/susceptibility indices. Salt-tolerant accessions were identified. An extracted bi-plot based on factor analysis confirmed the results of tolerance/susceptibility indices. There were significant correlations between STS and multivariate statistics. Root potassium cation (K⁺) concentration was higher in Melilotus species than the control species in all the salinity treatments. STS, root K⁺ concentration, leaf turgidity, and leaf succulence characteristics can be used for screening salinity-tolerance in Melilotus accessions. In all treatments, M. officinalis, M. indicus, and M. albus were salinity-tolerant species in descending order.

Abbreviations: Total biomass yield under control (Yp) and stress (Ys) mediums, geometric mean productivity (GMP), leaf area (LA), leaf tissue density (LTD), linear regression coefficient (b), mean productivity (MP), relative water content (RWC%), Succulence (S), specific leaf area (SLA), stress susceptibility index (SSI), stress tolerance index (STI), tolerance (TOL), water content at saturation (WCS), water saturation deficit (WSD), sodium chloride (NaCl), potassium cation (K⁺), sodium cation (Na⁺), analysis of variance (ANOVA), least significant difference (LSD), alfalfa control accession (CHA), Persian clover control accession (CHC), coefficient of variation (CV), statistics of factor (F) and discriminate function (D)     

Investigation on the Biodegradability and Antibacterial Properties of Nanohybrid Suture Based on Silver Incorporated PGA-PLGA Nanofibers

Polyglycolic acid-poly lactic glycolic acid (PGA-PLGA) electrospun nanofibers containing silver nanoparticles have been produced and twisted into the nanofibrous yarn. The morphology of nanofibers and produced yarns, as well as the mechanical properties of the yarns, were investigated. Furthermore, in vitro antibacterial properties and in vitro degradation behavior of yarns containing various silver nanoparticles were studied. SEM images confirmed that the addition of the silver nanoparticles into the polymer solution increases the fiber diameters. The result of the mechanical test of the yarns alone and used in two different forms of the knots was measured and results showed that the strength of the yarns without the knot was significantly more than that of others. The biodegradability test showed that the mechanical properties and the weight of the yarns were quickly reduced after subjecting to in vitro condition. The result of the antibacterial test indicated that the nanofiber yarns containing %3 silver nanoparticles were the most appropriate sample with a considerably antibacterial activity against both gram-positive bacterium Staphylococcus aureus and gram-negative bacterium Escherichia Coli with inhibition zones of 8.1 and 9.5 mm, respectively; which demonstrated that silver nanoparticles retained their effectiveness after the electrospinning process. Therefore the nanofibrous yarns containing silver nanoparticles could be successfully produced by the electrospinning process with the proper antibacterial property as a candidate for the surgical sutures.     

Effects of melatonin on oocyte maturation in PCOS mouse model

The purpose of oocyte in vitro maturation is generation of mature oocytes that could support future development. Efforts have been made to enhance oocyte developmental competence by developing optimal culture conditions. The present study is conducted to determine melatonin effects on quality of polycystic ovarian syndrome (PCOS) oocytes when it has been added during in vitro maturation, and immature oocytes were cultured in defined conditioned medium with and without different melatonin concentrations. Melatonin could significantly improve nuclear maturation of PCOS oocytes (81.1% vs. 56.3%, P < 0.05 were achieved with 10^?6 mol/L concentration). Cleavage rate was significantly higher in 10^?5 mol/L concentration compared to untreated oocytes in PCOS (54% vs. 35%, respectively) and it was significantly higher with 10^?6 mol/L concentration in the control group, 55% versus 38%, compared to untreated oocytes. This study showed that melatonin has the potential to induce oocyte nuclear maturation and guarantee fertilization potential. © 2016 Japanese Society of Animal Science     

Estimating Cape hare occupancy and abundance in southern Tunisia using spotlighting data

This study outlines the importance of integrating spotlighting data and occupancy modelling to estimate the spatial occupancy, abundance and habitat preferences of Cape hares Lepus capensis in southern Tunisia. Exploring the spatial distribution pattern of this species is problematic because of its nocturnal and secretive behaviour. In order to overcome these constraints, we used spotlight surveys on equidistant points along tracks to collect presence/absence data. Using a likelihood-based approach, we estimated occupancy and relative abundance of Cape hare populations in three national parks: Sidi Toui, Bouhedma and Jbil. We also combined the three parks in a single area to represent ‘southern Tunisia’ for investigating the factors affecting its distribution pattern. Sidi Toui showed the highest occupancy and relative abundance values (88.84 ± 10.95% and 7.97 hares km^?2, respectively). Bouhedma was also recognised as high-quality hare habitat with occupancy and relative abundance values of 61.70 ± 11.70% and 2.85 hares km^?2, respectively. The lowest occupancy (49.65 ± 26.25%) and relative abundance (2.10 hares km^?2) estimates were encountered in Jbil. The combined parks model suggested that part of the distribution pattern of Cape hares can be explained by habitat quality. Spatial occupancy over southern Tunisia showed a positive relationship between its occurrence and the availability of Poaceae and Plantaginaceae.     

Cross-resistance patterns of winter wild oat (<Emphasis Type="Italic">Avena ludoviciana</Emphasis>) populations to ACCase inhibitor herbicides

The level of resistance and patterns of cross-resistance to clodinafop, sethoxydim, and pinoxaden were examined in 12 putative resistant and one susceptible populations of winter wild oat (Avena ludoviciana) collected from Fars Province, in the southwest of Iran. The responses of biomass and length of coleoptiles to the increasing dosages of the three herbicides were determined in both whole-plant and seed bioassays. In the whole-plant bioassay, all 12 putative resistant populations were found to be resistant to clodinafop with resistance ratios (R/S) ranging from 1.76 to >47.04. Most clodinafop-resistant populations exhibited low levels of cross-resistance to sethoxydim. Three highly sethoxydim-resistant populations, F2, S2, and ES4, were slightly resistant to clodinafop. Six populations (M1, M2, F2, S2, S4, and ES4) showed high cross-resistance to pinoxaden with R/S values as large as 10.73 to 40.29. A highly clodinafop-resistant population, M2, was more sensitive to pinoxaden than the susceptible population. The results of the seed bioassay resembled those obtained from the whole-plant experiment suggesting seed bioassay as an inexpensive, rapid method for screening-resistant genotypes.