Browsing by Author "Mendes, Mehmet"

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Multidimensional Scaling Analysis of Morphological Spike Traits in Local Wheat Genotypes from the Van Lake Basin
(MDPI, 2025) Altuner, Fevzi; Jamal-Salih, Sana; Ozdemir, Burak; Oral, Erol; Mendes, Mehmet; Ulker, Mehmet; Pace, Loretta
Wheat landraces are considered a valuable resource of potential phenotypic variation that could be used in germplasm improvement. Here, we examined 588 local wheat genotypes collected from farmers' fields at 127 locations around Van Lake Basin and evaluated the morphological diversity and trait associations using Multidimensional Scaling Analysis. Spike and yield traits were measured and scored according to the UPOV and ICARDA phenotypic characterization criteria. Multidimensional Scaling Analysis divided the wheat samples into four main groups based on the number of spikelets (NOS), number of fertile spikelets (NFS), thousand-grain weight (TGW), and number of seeds per spike (NSS) and indicated a strong correlation between NOS and NFS. Furthermore, the analysis revealed that the glume and awn color of most of the genotypes was black, and they were within the locally known Karak & imath;l & ccedil;& imath;k group. Only two genotypes were excluded from the Karak & imath;l & ccedil;& imath;k group; No. 231 was within the Geverik local wheat group, and genotype No. 579 was found to be Tir. The Hevidik and Kirik groups had the same spike color, but the Hevidik group had spikes similar to compactum wheat, whereas the Kirik group had larger spikes. Finally, genotype No. 57 varied from all other genotypes when all the measured traits were taken into consideration. Overall, the Van Lake Basin landraces combine broad similarity with meaningful phenotypic heterogeneity shaped by local environments and traditional on-farm selection. These findings provide practical cues for conservation efforts and for the use of landraces as valuable resources in future wheat breeding programs.
A Study on the Effects of Wood Vinegar on Weeds and Cultivated Plants in the Wheat Agro-Ecosystems
(Parlar Scientific Publications (p S P), 2019) Koc, Ibrahim; Namli, Ayten; Mendes, Mehmet; Pinar, Suleyman Mesut; Cig, Fatih; Yardim, Erdal Necip
This study was conducted to determine the effects on the weeds and cultivated plants in the wheat agro-ecosystems of the wood vinegar in the biopesticide potential obtained from hazelnut shells on certain growth and yield parameters. The study was conducted based on the Randomized Blocks Testing Design with repeated four times. In the experiment, treatments of 0.5%, 1.0%, 2.0%, 3.0%, 4.0%, and 5.0% mL doses of wood vinegar were administered, and only tap water was given to the control group. It was found that the 4% mL dose had positive effects on cultivated plant height and that the 1% mL dose had positive effects on thousand kernel weight and seed per spike compared with the control. It was seen that its effect on weeds dry weight is changed according to the years (P=0.011). In 2015-2016, it was found that 3% mL increased and 0.5%, 1% and %5 mL decreased the weight of dry grass. In the test field; weeds determination is made from 12 families. In 2014-2015, Polygonum bellardii, Eremopoa altaica and Microthlaspi perfoliatum; and in 2015-2016, Eremopoa altaica, Erodium absinthoides, Lactuca serriola and Polygonum bellardii was seen most.
Type I Error Rates and Test Power for Some Outlier Detecting Tests
(Pushpa Publishing House, 2011) Yigit, Soner; Mendes, Mehmet; Mirtagioglu, Hamit
This study is conducted to compare some outlier detection tests such as Grubbs, Dixon, Chauvenet criterion and Weisberg t-test with respect to Type I error rate and test power. For this purpose, random numbers from normal population are generated by Monte Carlo simulation technique. Results of 50,000 simulation trials showed that the Weisberg t-test gave the most reliable results with respect to the others. Chauvenet criterion has followed this test. Dixon and Grubbs tests have not displayed reliable results except for studying with small sample sizes. As a result, regardless of the sample size being studied, Weisberg t-test should be used as detecting whether there is an outlier in the data set or not.