Effect of nitrogen on thiocyanate content of Brassica oleracea var. acephala leaves

An experiment was carried out to study the effect of nitrogen fertilizer application levels (0, 47, 94 and 188 kg N/ha) on thiocyanate contents of petioles and lamina of two Brassica oleracea L. var. acephala varieties (Thousand-headed kale and Georgia collards).The results showed that N application significantly decreased thiocyanate contents of both laminae and petioles. Applying 47, 94, 188 kg N/ha reduced thiocyanate of laminae and petioles by 26, 41 and 52% and 2, 9 and 39%, respectively. The results also showed that thiocyanate of leaves from Thousand-headed kale was significantly higher than that of Georgia collards. Lamina and petiole thiocyanates of Georgia collards were 79% and 83% of those of Thousand-headed kale, respectively.