Farklı Tarihlerde Ekilen Buğday (Triticum ssp.) Genotiplerinde Bazı Gelişme Dönemleri İçin Gerekli GDD (Growing Degree Days) Değerlerinin Belirlenmesi / Determination of Some Growth Stages Growing Degree Days (GDD) Values of Wheat (Triticum ssp.) Genotype

Abstract

Ozet : Bu calisma, 2000-2001 ve 2001-2002 yetisme sezonlarinda Harran Universitesi Ziraat Fakultesi deneme alaninda ilave sulanan kosullarda yurutulmustur. Calismada, farkli tarihlerde ekilen bugday cesitlerinin bazi gelisme donemleri icin gerekli GDD (Growing Degree Days) degerleri belirlenmistir. Denemede 5 ekim–18 ocak tarihleri arasinda 7’ser gun araliklarla, 16 farkli ekim tarihi kullanilmistir. Iki yillik sonuclarin ortalamasina gore; en yuksek sapa kalkma GDD degeri 19 ekim (824.2 0C), en dusuk GDD degeri ise 18 ocak (424.2 0C) ekim tarihinde belirlenmistir. En yuksek basaklanma GDD degerlerine 12 ekim (1651.1°C) ve 19 ekim (1649 °C), en dusuk degere ise 18 ocak (948.0 °C) tarihli ekimde ulasilmistir. Erken ekimden gec ekime dogru basaklanma GDD degeri azalmistir. Olgunlasma suresi GDD degeri 1814.8 °C ile (18 ocak ekim tarihi) 2988.5 °C (5 ekim ekim tarihi) arasinda degismistir. Ekim zamani geciktikce olgunlasma icin gereken GDD degeri azalmistir. Anahtar Kelimeler: bugday, ekim tarihi, GDD (Growing Degree Days) Determination of Some Growth Stages Growing Degree Days (GDD) Values of Wheat (Triticum ssp.) Genotypes at Different Sowing Times Abstract : This study aimed to determination of some growth stages Growing Degree Days (GDD) values in wheat on different sowing times. Sowing dates were between 5 October to 18 January with 7-days intervals. Field trials were carried out in the experimental area of Agriculture Faculty of Harran University in the growing seasons of 2000-2001 and 2001-2002 under the irrigated conditions. According to average of two years, the highest stem elongation stage GDD value was found at 19 October sowing date (824.2 0C), the lowest value was determined as a 424.2 0C at 18 January sowing date. The highest heading stage GDD value was found at 12 October (1651.1°C) and 19 October (1649 °C) sowing dates wheras the lowest value was 948.0 °C at 18 January sowing date. Heading stage GDD values decreased from erly to late sowing times. Maturation stage GDD values varied from 1814.8 °C (18 January sowing date) to 2988.5°C (5 October sowing date). When the sowing time delay, necessary maturation stage GDD values decreased. Key Words: wheat, sowing date, GDD (Growing Degree Days)