Browsing by Author "Yergin, Reyyan"

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Critical Period of Weed Control in Chickpea Under Non-Irrigated Conditions
(Tubitak Scientific & Technological Research Council Turkey, 2011) Tepe, Isik; Erman, Murat; Yergin, Reyyan; Bukun, Bekir
The present study was conducted during the growing seasons of 2005, 2006, and 2007 to determine the critical period of weed control (CPWC) in chickpea (cv. Aziziye 94). In order to evaluate the beginning of CPWC, weeds were allowed to compete at weekly intervals for 1 to 8 weeks after emergence (WAE) and, at the end of CPWC, plots were kept weed-free at weekly intervals for 1 to 8 WAE by periodic hand hoeing. The beginning and the end of CPWC were based on 5% acceptable yield loss (AYL) levels, which were determined by fitting logistic and Gompertz equations to relative yield data, representing increasing duration of weed-interference and weed-free period, estimated as growing degree days (GDDs). The major weed species were Centaurea depressa Bieb. and Bromus tectorum L. for the 1st year, Salsola ruthenica Iljin., Amaranthus sp. and Heliotropium europaeum L. for the 2nd year and Amaranthus spp., Salsola ruthenica Iljin., Sisymbrium septulatum DC. and Heliotropium europaeum L. for the 3rd year. Overall weed density was 190 plants m(-2) in 2005, 215 plants m(-2) in 2006, and 191 plants m(-2) in 2007. Yield losses were 26.4% in 2005, 31.5% in 2006, and 25.0% in 2007 when the crop was not weeded. It was found that at the 5% AYL level CPWC was 2.32 WAE to harvest in the 1st year, from emergence to harvest in the 2nd year, and from 0.34 WAE to harvest in the 3rd year. The present findings suggest that the determination of CPWC is crucial in chickpea production.
Critical Period of Weed Control in Winter Lentil Under Non-Irrigated Conditions in Turkey
(Academic Journals, 2008) Erman, Murat; Tepe, Isik; Bukun, Bekir; Yergin, Reyyan; Taskesen, Mehtap
This study was conducted during the growing seasons of 1998-1999 and 2003-2004 to determine the critical period of weed control (CPWC) in winter-lentil (cv. Sazak-91). The experiments were laid out in a randomised block design with four replications. The beginning and end of CPWC were based on 5% acceptable yield loss levels which were determined by fitting logistic and Gompertz equations to relative yield data, representing increasing duration of weed-interference and weed-free period, estimated as growing degree days (GDD). The results indicated that CPWC for seed yield was between 237 and 846 GDD in the first year and between 123 and 414 GDD in the second year, while CPWC for biomass was between 216 and 820 GDD in the first year and between 212 and 374 GDD in the second year. Thus weeds should be controlled from the first week after the onset of regrowing stage of the crop in spring up to 7th week for winter-lentil to avoid losses above 5%.
Determination of Some Emergence Characteristics and Germination Physiolgy of Great Bur Parsley (Turgenia latifolia (l.) Hoffm.)
(2007) Yergin, Reyyan; Tepe, Işık
Bu çalışmada, başta tahıllar olmak üzere birçok tarım alanında sorun oluşturan geniş yapraklı pıtrak (Turgenia latifolia (L.) Hoffm.) tohumlarının çimlenme sıcaklığının belirlenmesi, canlılık oranı, dormansiyi kırma çalışmalarının yanı sıra çimlenme üzerine tuzluluk ve pH gibi faktörlerin etkileri araştırılmıştır. Çalışmada kullanılacak olan geniş yapraklı pıtrak tohumları, Van merkezinden tarım alanlarından rasgele seçilen bölgelerden 2003-2004 yıllarında toplanmıştır. T. latifolia tohumlarının %98 oranında canlı olduğu, maksimum çimlenme sıcaklığı 2003 yılı için 25ºC, 2004 yılı için 20ºC, minimum çimlenme sıcaklığı ise her iki yıl için 5ºC olarak tespit edilmiştir. Optimum çimlenme sıcaklığı ise 15ºC olarak belirlenmiştir. pH'ın ve sülfürik asit uygulamasının çimlenme üzerine etkili olmadığı, tuzluluğun ise hem canlılık hem de çimlenme üzerine olumsuz etkiye sahip olduğu gözlenmiştir. HPLC yöntemi kullanılarak yapılan hormon analizi sonucu dışardan uygulanan GA3'in tohumlar tarafından alındığı ancak çimlenmeyen tohumlarda bazı metabolik faaliyetler gerçekleşmediği için birikmenin olduğu tahmin edilirken, GA3 uygulamasında en yüksek çimlenme oranı 2003 yılı için 150 ppm'de %9, 2004 yılı için 100 ppm'de %4.5 olarak tespit edilmiştir. 5ºC sıcaklıkta bekletildikten sonra farklı ortamlarda çimlendirilen tohumların toprak derinliğinde en iyi 0-2 cm derinlikte çıkış yapabildiği, soğukta bekletme süresi arttıkça çimlenme oranın arttığı ve bu bekletilme süresinden sonra en yüksek çimlenmenin 5ºC'de olduğu tespit edilmiştir. Çok güçlü dormansiye sahip olan tohumların bir kısmının dormansisinin kırılmasında meyve kabuğu ve soğukta bekletmenin önemli etkiye sahip olduğu sonucuna varılmıştır. Anahtar kelimeler: Yabancı ot, Turgenia latifolia, Tohum, Çimlenme fizyolojisi, Dormansi.
Effect of Atrazine Applications on Weed Growth and Yield at Different Irrigation Levels in Corn (Zea Mays L.) Growth
(Academic Journals, 2010) Kaya, Ilhan; Celebi, Seyda Zorer; Yergin, Reyyan; Yilmaz, Ibrahim Hakki
Corn (Zea mays L.), for silage, is very important in animal feeding because winter seasonal conditions last longer in Eastern Turkey. Corn yield components were investigated in plots, in which herbicide had been applied and also not applied at different irrigation levels in this study. The study lasted for two years and soil-water content was kept at five different levels [96% (I-1), 63% (I-2), 32% (I-3), 15% (I-4) and 4% (I-5)]. The species and intensities of the weeds at the irrigation levels were determined in the study. Plant length, green and dry herbage yields, leaf, stem and ear ratios were studied as criteria for corn yield. At the same irrigation levels, higher efficiency values were determined according to non applied plots in the atrazine applied plots. In both years, the lowest green herbage and dry herbage yields were determined at I-4 and I-5 irrigation levels. The weeds that are mostly seen on the plots, in which atrazine had not been applied are Alopecurus myosuroides Huds. and Sinapis arvensis L, respectively. Similarly, for both years, high densities of weeds were observed in the highly moisturized lands. The atrazine activities increased at the I-1 and I-2 irrigation levels in which water content of the soil is high.
Effects of Sowing Methods and Rates on Weeds, Grain Yield and Some Yield Components of Wheat
(Ankara Univ, Fac Agr, 2011) Kaydan, Digdem; Tepe, Isik; Yagmur, Mehmet; Yergin, Reyyan
This research was conducted to determine the effects of different sowing rates (450, 550 and 650 seed m(-2)) and sowing methods (sowing to the rows, broadcasting to seeding depth and contrary rows with 90 degrees) on weeds, grain yield and some yield components of wheat local "Tir" variety (Triticum aestivum L. ssp vulgare Vill. v. leucospermum Korn) under dryland condition of Van in 2006-07 and 2008-09 winter growing seasons. It was found that contrary rows with 90 degrees unaffected to reduce weeds density but it was highly effective sowing methods to decrease weeds biomass. However, higher seeding rates, in the current study, reduced insignificantly weeds density, but it reduced weed biomass. In the current study, sowing methods and seeding rates significantly affected grain yields and yields components. The highest grain yield was obtained 650 seed m(-2) and sowing to contrary rows with 90 degrees.
Effects of the Weed Density on Grass Yield of Alfalfa (Medicago Sativa L.) in Different Row Spacing Applications
(Academic Journals, 2010) Celebi, Seyda Zorer; Kaya, Llhan; Sahar, A. Korhan; Yergin, Reyyan
This study, in which the effects of different row spacing applications on weed density and on grass yield of Medicago sativa L. were investigated, was carried out in Van-Turkey from 2006 - 2008. Randomized blocks design was adopted with three replications. Row spacing applications of 20, 30, 40, 50, 60 and 70 cm were tested. The alfalfa plant height, yield of green herbage yield, dry matter yield, crude protein rate and crude protein yield were investigated. In addition, the weed densities at different row spacing distances were determined. The highest plant heights were obtained in 40 cm row spacing application in the first year and in 20 cm row spacing application in the second year. The highest dry matter and crude protein yields were obtained in 20, 30 and 40 cm row spacings in the first year and in 20 cm row spacing applications in the second year. The most intense weed was Alopecurus myosuroides Huds in 2007 and Amaranthus retroflexus L. in 2008. The least weed density was found in 20 cm row spacing during all three before cutting periods in the first year of study and this was found in 30 cm row spacing application in first before cutting period and in 20 cm row spacing application in the second and third before cutting periods in the second year.