Effect of Foliar Application of Humic and Fulvic Acids on Yield and its Components of Some Carrot (Daucus carota L.) Cultivars
This investigation was conducted at the Experiment Station of the Faculty of Agriculture, Cairo University on 14 and 16 November in winter seasons of 2015-2016 and 2016-2017 to study the effect of growth stimulants (humic acid and fulvic acid ) as foliar spray on some carrot cultivars. The experimental units were arranged in a split plot design with three replications. The growth stimulants were in main plot whereas the cultivars were assigned in sub-plots. The experiment includes 12 treatments which were the combination of control (without spray), humic acid (HA) (1g/l) and fulvic acid (FA) (0.5g/l) as foliar spray and four cultivars; viz Corall, Terracotta (Takii seeds), Siroco and Exelso (Semences seeds).all of tested cultivars follow chantenay type. The foliar application, were applied after month of sowing and then repeated at 45, 60 and 75 days from sowing. Results show that the HA at 1g/l treatment increased significantly average root weight, yield/plot, economic yield and harvest index. While, FA at 0.5g/l treatment improved significantly leaves chlorophyll content, roots dry matter, carbohydrates, carotenoids, nitrogen and phosphorus. Siroco cultivar gave the highest values of average root weight and yield/plot. Exelso cultivar had the greatest dry matter and harvest index. The maximum values of chlorophyll in leaves and carbohydrates in roots were observed in Terracotta cultivar.