Özet Bu araştırma, farklı dikim zamanı ile bitki sıklığının Erzurum koşullarında yetiştirilen lahanada gövde uzunluğuna, açık yaprak adedine, açık yaprak ağırlığına, baş tutma oranına, baş çapma, baş yüksekliğine, baş ağırlığına ve verime etkilerini tespit etmek için yürütülmüştür. Araştırma sonunda elde edilen sonuçlar şu şekilde özetlenebilir. (1) pazarlanabüir en yüksek ürün I. dikim zamanında ve 15x15 cm*lik bitki sıklığında meydana gelmiştir; (2) baş tutma oranı, baş çapı ve baş ağırlığı I. dikim zamanında ve 1 00x75 cm lik bitki sıklığında en fazla olmuştur; (3) açık yaprak saıyısı III. dikim zamanında ve 75.x*50 cm lik bitki sıklığında; açık yaprak ağırlığı ise /. dikim zamanında ve 50x50 cm lik bitki sıklığında en az olmuştur. Summary   The Effects of Planting Time and Spacing on Growth and Yield of Cabbage in Erzurum Conditions   This study was carried out to determine the effects of planting times and spacing on plant growth and yield in Erzurum conditions. Plants were grown at the Agricultural Experiment Station No 6 in Erzurum, Turkey. Cabbage cultivar named Zöhrap locally, was grown in the field conditions. Three different planting time, May 13, May 23, and June 3; and four different spacing, 50 by 50 cm, 75 by 50 cm, 75 by 75 and 100 by 75 cm were used. At the end of the harvest, total yield and percent of heading were determined. Diameter, height of heads, height of stem; number and weight of open leaves were determined, too. Data obtained in this study were analyzed statistically and Duncan's Multiple Range Test was applied. The following results were obtained: 1- The highest yield was obtained in the earliest planting with 75 by 75 cm spacing, and the lowest yield in the last planting with 50 by 50 cm spacing. 2- Low plant density increased head diameter but delayed planting time decreased. 3- The highest and lowest head-heights were obtaineden the first planting with 100 by 75 cm and the last planting with 50 by 50 cm, respectively. 4- Percent of heading increased with decreasing of plant density in the first planting. The highest percentage of heading in cabbage is obtained in the last planting time with 75 by 75 cm spacing. 5- The highest and lowest marketable head weights were obtained in the first planting with 100 by 75 cm and in the last planting with 50 by 50 cm, respectively. 6- The height of stems was greatest in 2 nd planting with 75 by 50 cm. 7- The number and weight of open leaves were highest in 3 rd planting time with 100 by 74 cm spacing.