Chicory plants, cv. Amarela and Pão de Açúcar, were hidroponically grown to determine growth and yield under five ammonium and nitrate N concentrations in the nutrient solution. Sowing was made in rows placed 0.05m apart, over a 0.15m deep sand growing bed supported by fibber cement tiles. After emergency, plants were thinned to a plant density of 1,600plants m-2. A standard nutrient solution was used, with the composition of, in mmol L-1, 11.0 de NO3-; 1.5 H2PO4-; 6.5 SO4-2; 7.5 Ca+2; 10.0 K+ and 1.5 Mg+2, and, in mg L-1, 0.42 Mn; 0.26 Zn; 0.05 Cu; 0.50 B; 0.04 Mo, and 4.82 chelated Fe. Treatments were total N concentrations of 11.0; 16.0; 21.0; 26.0 and 31.0mmol L-1 in the nutrient solution, containing NH4+ concentrations of zero; 2.5; 5.0; 7.5 and 10.0mmol L-1, respectively. The nutrient solution was delivered to plants four times a day. A completely randomised split plot experimental design was used, with four replications. Plants were harvested at 35; 59; 76 and 97 days after sowing, by cutting the shoot at 0.02m height, and fresh and dry mass was determined. Maximum yield was reached using the nutrient solution with 16mmol L-1 of total N, containing 2.5mmol L-1 of NH4+.
Cichorium intybus; fertigation; hydroponics; ammonium
