بررسی تاثیر تاریخ کاشت و مقدار کود ازت بر روی صفات کمی و کیفی دو رقم اسفناج

A study was carried out to determine the best sowing date and nitrogen level, which has minimum N accumulation in two spinach varieties. This experiment was done in completely randomized blocks (split, split plots) with three replications. The factors were sowing date in 4 levels (23 rd September and 15 days interval between following dates) and spinach variety (German wide leaf Vt. and Viroflay) and nitrogen fertilizer in four levels (60,90,120/1 SOkg/haN). Each plot consisted of 3 planting rows with 3 meters distance between them which seeds planted by internal and middle distance of 40 and 25 cm respectively. Results showed no significant difference between nitrogen, fertilizers and spinach varieties whereas, effects of sowing date intraction between nitrogen fertilizer and sowing date and also triple interactions between N fertilizer, spinach variety and sowing date were proved to be significant at 1% level. The heighest yield (32-98 ton/ha) was obtained from treatment German wide leaf in the third sowing date (22nd October) and 150 Kg/ha nitrogen fertilizer.