Effects of Different Levels and Application Times of Humic Acid on Root and Leaf Yield and Yield Components of Forage Turnip ( Brassica rapa L.)

摘要

The effects of four humic acid levels (0, 600, 1200 and 1800 mL ha^-1) and three application times (after emergence onto leaves, after 1 month of sowing date onto leaves and after 2 month of sowing date onto leaves) on root and leaf yields and some yield components of forage turnip were evaluated under the Black Sea Coastal Area Conditions, Turkey in the 2003 and 2004 growing seasons. The root yield, root dry matter yield, root crude protein yield, root diameter, root length, leaf yield, leaf dry matter yield and leaf crude protein yield were determined. Humic acid significantly affected most of the yield components determined in forage turnip. Root and leaf yields and their yield components increased along with increase of humic acid . The highest root and leaf dry matter yields were obtained from the 1200 mL ha^-1 humic acid level and second application time. Forage turnip gave the greatest response to humic acid application in terms of yield and yield components under the Black Sea Coastal Area Conditions, Turkey.