Oral Duzdemir

Single and double inoculation with Azospirillum/Trichoderma: the effects on dry bean and wheat

A plant growth-promoting rhizobacterium (Azospirillum brasilense Sp7) and a bio-control fungus, which can solubilize insoluble phosphorus (Trichoderma harzianum Rifai 1295-22), were evaluated for their single and combined effects on dry bean (Phaseolus vulgaris) and wheat (Triticum aestivum L.) grown in soil. A pot experiment with bean and a field experiment with both bean and wheat were established. In contrast to single inoculation of Trichoderma, the single inoculation of Azospirillum and the double inoculation did not significantly (P >0.05) increase nodule numbers and nodule mass at 45 days after planting in pot grown beans. However, the Azospirillum inoculation with supplementary phosphorus significantly (P <0.05) increased nodule mass. There were no significant (P >0.05) differences among the inoculation treatments for plant dry weight, total plant nitrogen, and total plant phosphorus at 45 days after planting in both pot and field experiments with bean. However, the combined inoculation and rock phosphate application at 1 Mg ha−1 significantly (P <0.05) increased bean seed yield, total seed nitrogen and phosphorus in the bean field trial. This treatment more than doubled the mentioned properties compared to the control. The microbial inoculations, with the exception of the combined inoculation, significantly (P <0.05) increased total seed nitrogen, but never affected seed yield in the wheat field trial (P >0.05). The combined inoculation improves many plant and yield parameters and, therefore, has some advantages over single inoculation provided that rock phosphate was supplied at an amount not exceeding 1 Mg ha−1. Higher rock phosphate application rates decreased many plant and yield parameters in our study.

Alterations in antioxidant enzyme activities and proline content in pea leaves under long-term drought stress

The effects of long-term drought stress on chlorophyll, proline, protein and hydrogen peroxide (H2O2) contents, malondialdehyde (MDA) in terms of lipid peroxidation and on the changes in the activities of antioxidant enzymes such as superoxide dismutase (SOD, EC 1.15.1.1), ascorbate peroxidase (APX, EC 1.11.1.11), catalase (CAT, EC 1.11.1.6) and peroxidase (POX; EC 1.11.1.7) in the leaves of pea (Pisum sativum L.) were studied in field conditions. Chlorophyll and protein contents in leaves decreased significantly with increased drought stress. The proline content increased markedly under water deficit. MDA amounts were elevated as a result of water shortage, whereas H2O2 content changed slightly in pea leaves exposed to drought stress. Drought stress markedly enhanced the activities of SOD, CAT and POX but slightly changed the activity of APX. We conclude that in field conditions, long-term water shortage increased the susceptibility to drought in peas.

Assessment of genotype x environment interaction on yield and yield components of durum wheat genotypes by multivariate analyses

Wheat breeders have to determine the new cultivars and lines responsive to the environmental changes for grain yield and yield components. Therefore, this study was conducted to evaluate 25 durum wheat (Triticum turgidum spp. durum ) genotypes including 12 registered cultivars and 13 advanced breeding lines for their stability grown in three different locations (Tokat-Kazova, Diyarbakir and Sivas-Ulas) of Turkey for two growing seasons (2005-2006 and 2006-2007), and to select genotypes having desirable traits to be used in future durum wheat breeding program. Field trials were conducted in a randomized complete block design with three replications at each location. Days to heading, plant height, number of spikes per square meter, number of kernels per spike, spike weight, 1000 kernel weight and grain yield of the genotypes were evaluated in each location. The regression coefficient ( bi) of Finlay and Wilkinson (1963) and mean square of deviation from regression (S 2 d) of Eberhart and Russell (1966) were used as the stability parameters. The results of combined analysis of variance showed a strong influence of the locations on plant height, number of spikes per square meter, number of kernels per spike, spike weight, 1000 kernel weight and grain yield. Genotypic effects were mainly observed for spike length and test weight. Year had strong impact only on the days to heading. Ecological conditions of Diyarbakir among locations offer the better opportunity for production of durum wheat. Line 5 and cultivar Gidara were both stable in yield ability and also appeared the stable group based on the cluster analysis. In the first principal component days to heading, number of spikes per square meter and spike length were the most important traits contributing to variation that obtained about 44.3%. There was a positive relationship between grain yield and number of spikes per square meter together test weight, whereas days to heading and spike length were negatively correlated to grain yield. The results of this study also imply that Line-5 and cultivar Gidara among genotypes were the most stable cultivars and can be used as breeding materials. The days to heading, number of spikes per square meter and spike length could be adequate to introduce the differences among genotypes.

Quality characteristics of registered cultivars and advanced lines of durum wheats grown in different ecological regions of Turkey

Sakin, M. A., Sayaslan, A., Duzdemir, O. and Yuksel, F. 2011. Quality characteristics of registered cultivars and advanced lines of durum wheats grown in different ecological regions of Turkey. Can. J. Plant Sci. 91: 261-271. In this study, pasta-quality-associated characteristics of 25 durum wheat genotypes were investigated. Durum wheat genotypes consisted of 13 advanced experimental lines and 12 registered cultivars that were grown in three different locations of Turkey for 2 yr. Genotype, location, year and their interactions were found to be statistically significant in terms of all investigated quality characteristics. Mean quality parameters for the genotypes varied as follows: yellowberry kernel 1.7-6.1%, pigment content 3.67-8.31 mg kg-1, lipoxygenase (LOX) activity 12.9-27.9 EU g-1, protein content 10.8-11.8% (14% mb), gluten index (GI) 12-61, sodium dodecyl sulphate-sedimentation volume 17.3-28.7 mL, specific sedimentation volume 1.60-2.52 mL. Of the genotypes, 10 contained γ-gliadin 45 and six γ-gliadin 42 proteins. Except for Zenit, none of the registered cultivars and advanced experimental lines investigated in this study were able to meet simultaneously the requirements for high-quality pasta products; yet certain experimental lines prevailing in specific quality characteristics, such as Line-Gdem-2, Line-Gdem-12 and Line-20, may be used for further breeding purposes. The results of this study also imply that grain yield and quality should be taken collectively into consideration in wheat breeding programs.

Response of cowpea (Vigna unguiculata) to salinity and irrigation regimes.

Abstract The effects of salinity and irrigation regimes on yield, growth, and water consumption of cowpea (Vigna unguiculata) were determined in two different experiments. The first experiment focused on cowpea responses to irrigation water with six different levels of salinity (0.7, 2.0, 3.0, 4.0, 5.0, and 7.0 dS m−1). In the second experiment four different amounts of water (1.43, 1.0, 0.75, and 0.50 times of depleted water) were applied to cowpea plants. Seed and pod yields of cowpea decreased significantly for the soil salinity values higher than 9.0 dS m−1. As soil salinity increased, water consumption of cowpea decreased. Therefore, the effect of salinity in lowering evapotranspiration should be considered in irrigation planning and scheduling of cowpea. Either excessive or limited water applications caused decreases in seed and pod yields of cowpea. Yield response factor (Ky), from the relationships between relative evapotranspiration and relative yield decrease, were 0.98 and 0.92 for pod and seed yields, respectively. It is concluded that cowpea is tolerant to water stress in terms of seed and pod yields.

Functional analysis of fertiliser use on chickpea (Cicer arietinum) farms: A case study from Turkey

Abstract Fertiliser use in chickpea (Cicer arietinum) grown under dry conditions was analysed from an economic point of view. In addition, a simple relationship between output (amount of chickpea) and inputs (fertiliser cost, pesticides cost, chickpea production area, labour, and amount of seed) was determined. The Tokat province of Turkey was chosen as the research area because it was the main chickpea production area. To study the effects of fertiliser use on chickpea production, 74 farmers were randomly selected and surveyed. Research findings were as follows: (1) gross and net profit was negative for the fertiliser user group and non‐fertiliser user group; (2) lack of technical knowledge and high input prices were the main reasons for unbalanced fertiliser use by farmers; (3) chickpea production area and fertiliser cost were the most important factors affecting chickpea production; (4) chickpea production was little effected by labour; (5) amount of seed and total pesticide cost were not significant in the model; (6) farmers should increase average chickpea production area to use resources efficiently.

Factors affecting fertiliser use in chickpea (Cicer arietinum) growing: A case from Turkey

Abstract A farmer survey was carried out in Tokat Province, Turkey to determine the relationship between fertiliser use in chickpea (Cicer arietinum) crops and grower profile (age, education level, land ownership, etc) and other physical factors (farm size, soil analysis, chickpea production area). The chi‐square (χ2) test was used to determine the relationship. There was a statistically significant relationship between fertiliser use and chickpea production area. There was no significant relationship between farm size and decision making, the amount and type of fertiliser, between farmer education level and fertiliser use, between farmer age and fertiliser use, and between decision making and the amount and type of agro‐chemicals and land ownership. in addition, the response of farmers to different questions (whether they used fertiliser to grow chickpea or not, where they purchased fertiliser, and their criteria for deciding the amount and type of fertiliser used in chickpea cultivation, whether they made soil and leaf analyses and the reasons for not using soil and leaf analyses for the use of chemical fertiliser) were analysed.