http://www.trakya.edu.tr/Enstituler/FenBilimleri/Dergi/net/index.htm Trakya Univ J Sci, 4(2): 187-194, 2003 ISSN 1302 647X DIC: 90LATT410312030104 INVESTIGATIONS ON YIELD AND QUALITY OF KOHLRABI (Brassica oleraceae var. gongylodes L.) IN THE TRAKYA REGION of TURKEY Levent ARIN, Ahmet SALK, Murat DEVECI, Serdar POLAT Department of Horticulture, University of Trakya, 59030 Tekirdağ, Turkey, e-mail: arinlevent@hotmail.com Received : 09.04.2003 Accepted : 28.07.2003 Abstract: This research was carried out to determine the possibility of growing kohlrabi (Brassica oleraceae var. gongylodes L.) under Trakya (Turkey) conditions during the spring and fall growing periods in the year of 2000. In each period, three kohlrabi cultivars (Express Forcer, Neckar, Lahn), two seedling ages (four or six weeks old) and three planting dates (at two week intervals in April, May for spring and in September, October for fall), with respect to yield and quality characteristics, were evaluated. Cultivars Neckar and Express Forcer had higher yield and quality than Lahn in both seasons. Higher yield was obtained from six weeks old seedlings in the spring, while a period of four weeks was sufficient for growing seedlings in fall. Key words : cultivars, kohlrabi, planting date, seedling age, yield Trakya Bölgesi'nde Alabaş (Brassica oleraceae var. gongylodes L.) Verim ve Kalitesi Üzerine Araştırmalar Özet: Bu araştırma 2000 yılı ilkbahar ve sonbahar döneminde Trakya koşullarında alabaş (Brassica oleraceae var. gongylodes L.) yetiştirme olanağını belirlemek amacıyla yürütülmüştür. Her bir periyotta üç alabaş çeşidi (Express Forcer, Neckar, Lahn), iki fide yaşı (dört ve altı haftalık) ve üç dikim zamanı (iki hafta aralıklarla ve ilkbaharda Nisan ve Mayısta, sonbaharda Eylül ve Ekimde) verim ve kalite özellikleri bakımından değerlendirilmiştir. Neckar ve Exp- ress Forcer çeşitleri her iki sezonda da Lahn'dan daha yüksek verim ve kalite vermiştir. Sonbaharda dört haftalık süre fide yetiştirme süresi yeterliyken, ilkbaharda altı haftalık fidelerden daha yüksek verim elde edilmiştir. Anahtar kelimeler : alabaş, çeşit, dikim zamanı, fide yaşı, verim Introduction Turkey has 79 million hectares area with a wide variety at soil and climate. A large range of crops spe- cies including many horticultural crops are grown in approximately 36% of this land area. In Turkey, pro- duction of horticultural crops is around 29 million tons and approximately 70% of this production is vegetable crops. The country is among the top five vegetable producing countries in the world in term of production and area. Vegetable crops are commonly grown in Mediterranean (south), Aegean (west) and Marmara (northern-west) regions. Tomatoes, water melons, on- ions melons and cucumbers are the most commonly grown vegetable crops in Turkey. Cabbage, belonging to Cruciferae family, ranks among the top eight with a total production of approximately 577 000 tons. Vege- table crops also have a significant place in the agricul- tural exports of the country. For instance, Turkey ex- ported 370 000 tons of fresh vegetables in 1999, which corresponds to 19 million US$. Export of fresh as well as processed vegetables, is a rapidly growing agro-industry sector in Turkey. Russian Federation, Germany, Saudi Arabia are the biggest importing countries of Turkish vegetables, although Turkish vegetal products (including vegetables) are exported to 50 countries, (Anonymous a, 2000; Anonymous b, 2000; Vural et al., 2000). Trakya which is located in north-west of the coun- try has a wide range of climates and soil conditions and therefore almost all vegetables can be grown. But, the greater part of agricultural land is being used to produce the field crops such as wheat and sunflower. The gross income value of vegetables is over 4.5%, while vegetables utilize 1.03% of the total agricultural area of the province. The demand for vegetables is on the rise due to in- creasing population, changing food habits, realization of high the nutritional value of vegetable crops and Original Article/Orijinal Makale