Assessing L2 vocabulary depth with word associates format tests: issues, findings, and suggestions

Word Associates Format (WAF) tests are often used to measure second language learners’ vocabulary depth with a focus on their network knowledge. Yet, there were often many variations in the specific forms of the tests and the ways they were used, which tended to have an impact on learners’ response behaviors and, more importantly, the psychometric properties of the tests. This paper reviews the general practices, key issues, and research findings that pertain to WAF tests in four major areas, including the design features of WAF tests, conditions for test administration, scoring methods, and test-taker characteristics. In each area, a set of variables is identified and described with relevant research findings also presented and discussed. Around eight topics, the General Discussion section provides some suggestions and directions for the development of WAF tests and the use of them as research tools in the future. This paper is hoped to help researchers become better aware that the results generated by a WAF test may vary depending on what specific design the test has, how it is administered and scored, and who the learners are, and consequently, make better decisions in their research that involves a WAF test

Effects of Salinity and Plant Growth Promoting Rhizobacteria on Some Physiological Traits and Grain Yield of Hulled Wheat Compared to Durum Wheat

Scientific data on the hulled wheats is scarce. Therefore, changes in some physiological attributes including carotenoids concentration, antioxidant enzymes activity, malondialdehyde content (MDA), cell membrane stability index (MSI) and grain yield in a hulled tetraploid wheat (i.e. "Joneghan") and  a durum wheat cultivar (i.e. "Yavaroos") in response to salinity and plant growth promoting rhizobacteria (PGPR) were studied using a split-factorial based on randomized complete block design at Research Farm, Isfahan University of Technology, Isfahan, Iran in 2013. Three levels of irrigation water salinity (control, 100 and 200 mM of NaCl) were chosen as main plots and the two tetraploid wheat genotypes and three PGPR strains (550, 57 and UW3) and bacteria-free control were considered as subplots. Salinity led to significant decreases in grain yield/m2 (nearly 30%), activity of the antioxidative enzymes of catalase (CAT), peroxidase (POX) and ascorbate peroxidase (APOX) and carotenoids concentration. Salinity led to a decrease in MSI and an increase in MDA content, indicating salt-induced damages to the cells. Bacterial strains left different effects on the above-mentioned traits. Strain 550 led to 44% increase in grain yield of the two genotypes at the absence of salt, though strain UW3 led to 24% increase in grain yield of the genotypes, when grown at the presence of 200 mM of NaCl. Though, the bacterial strains led to increase in MSI of the salt-treated plants. From the data obtained in the present field study we can conclude that the PGPR efficacy in the mitigating salt stress in tetraploid wheat is genotype-, salt level- and strain-specific. The "Joneghan" hulled tetraploid wheat was out-performed by the "Yavaroos" durum wheat, though its yield penalty due to saline water did not appear to differ from that of the latter genotype

Evidence for differential lipid peroxidation and antioxidant enzyme activities in Sesamum indicum L. genotypes under NaCl salinity

As sesame is a somewhat neglected crop, information concerning its response to salinity is lacking. The effects of NaCl stress were studied on seven genotypes of Sesamum indicum L. The 6-weeks-old sesame seedlings were treated with different NaCl concentrations (0, 30, and 60 mM). The NaCl caused significant decreases in fresh and dry mass of all genotypes; however responses of genotypes to the salt were significantly different. Based on the data obtained for fresh and dry mass accumulation, the genotypes were divided into two groups: i.e. salt-tolerant (Ardestan, Varamin, and Darab) and salt-sensitive (Naz-Takshakheh, Naz-Chandshakheh, Yekta and Oltan). Lipid peroxidation was recorded to be the lowest in cv. 'Varamin', 'Darab', and 'Ardestan' (tolerant group), whereas it was recorded to be maximum in genotypes 'Naz-Takshakhe', 'Naz-Chandshakhe', 'Oltan' and 'Yekta' (sensitive group) in the 60 mM NaCl treatment. In both 30 and 60 mM NaCl treatments, the activities of SuperOxide Dismutase (SOD), Catalase (CAT), Ascorbate Peroxidase (APX) and Glutathione Reductase (GR) were found to be higher in the tolerant group, compared to the sensitive group of genotypes. The accumulation of proline in the sesame leaves under saline conditions was higher in tolerant group, compared to the sensitive genotypes. It seems that in the salt-tolerant genotypes of sesame, increases in antioxidant enzymes activities and proline accumulation, along with a lower lipid peroxidation at cellular membranes, led to a higher level of tolerance to the salt

Effects of Salinity and Plant Growth Promoting Rhizobacteria on Some Physiological Traits and Grain Yield of Hulled Wheat Compared to Durum Wheat

Scientific data on the hulled wheats is scarce. Therefore, changes in some physiological attributes including carotenoids concentration, antioxidant enzymes activity, malondialdehyde content (MDA), cell membrane stability index (MSI) and grain yield in a hulled tetraploid wheat (i.e. "Joneghan") and  a durum wheat cultivar (i.e. "Yavaroos") in response to salinity and plant growth promoting rhizobacteria (PGPR) were studied using a split-factorial based on randomized complete block design at Research Farm, Isfahan University of Technology, Isfahan, Iran in 2013. Three levels of irrigation water salinity (control, 100 and 200 mM of NaCl) were chosen as main plots and the two tetraploid wheat genotypes and three PGPR strains (550, 57 and UW3) and bacteria-free control were considered as subplots. Salinity led to significant decreases in grain yield/m2 (nearly 30%), activity of the antioxidative enzymes of catalase (CAT), peroxidase (POX) and ascorbate peroxidase (APOX) and carotenoids concentration. Salinity led to a decrease in MSI and an increase in MDA content, indicating salt-induced damages to the cells. Bacterial strains left different effects on the above-mentioned traits. Strain 550 led to 44% increase in grain yield of the two genotypes at the absence of salt, though strain UW3 led to 24% increase in grain yield of the genotypes, when grown at the presence of 200 mM of NaCl. Though, the bacterial strains led to increase in MSI of the salt-treated plants. From the data obtained in the present field study we can conclude that the PGPR efficacy in the mitigating salt stress in tetraploid wheat is genotype-, salt level- and strain-specific. The "Joneghan" hulled tetraploid wheat was out-performed by the "Yavaroos" durum wheat, though its yield penalty due to saline water did not appear to differ from that of the latter genotype

Evaluation of Some Physiological and Grain Yield Responses of Chickpea (Cicer arietinum L.) Cultivars to Irrigation Regimes and Salinity

In order to investigate some physiological responses and grain yield of five chickpea cultivars under different levels of moisture and salinity, two experiments (i.e. a pot and a field experiment) were conducted in 2012. In the pot experiment, effects of four salt levels (i.e. control, 50, 75 and 100 mM of NaCl) on five chickpea cultivars, i.e. Arman, Azad, Hashem, ILC-482 and Noorabad were studied in a 3-replicate factorial completely random design experiment. In the field experiment, responses of the latter cultivars to four moisture regimes (i.e. no irrigation, irrigation after 75, 100 and 150 mm of evaporation) based on evaporation from a Class-A Standard Pan were evaluated in a 3-replicate split-plot randomized complete block experiment. Data obtained from the pot experiment indicated that proline accumulation, Na+ concentration and Na+/K+ were increased, but K+ concentration, relative water content and plant dry mass were decreased with increase in salt level. Since cultivar ILC-482 tended to indicate a greater proline concentration, in contrary to a smaller Na+ concentration and plant dry mass, compared to the remaining cultivars, it seemed to be more tolerant to the salinity. Data from the field experiment confirmed that delayed irrigation leads to increase in proline accumulation and decreases in leaf area index, plant dry mass and grain yield. Irrigating chickpea after 75, 100 and 150 mm evaporation resulted in 1964, 1675 and 1503 kg/ha of grain yield, leading to 114%, 84% and 64% increases in grain yield, respectively, compared to the no irrigation control. Cultivars Noorabad and Hashem produced the greatest (i.e. 1610 kg/ha) and smallest (i.e. 1361 kg/ha) grain yields, respectively. According to the findings of this one-year field study, seeding cultivar Noorabad concomitant to irrigation after 150 mm evaporation could, perhaps, lead to a substantial increase in grain yield in Noorabad region of the Lorestan Province in Iran. Though, cultivar ILC482 tended to indicate a more stable plant dry mass, when subjected to different irrigation regimes and different levels of saline water