Effect of Cultivation Methods and Drip Irrigation on the Yield of Roots and the Quality of Chicons of Witloof Chicory

In the years 2005-2007, a study was carried out to investigate the effect of surface and subsurface drip irrigation on the yield of witloof chicory in flatground and ridge cultivation. Irrigation began at a soil water potential of 30-40 kPa. Irrigation was found to have a beneficial effect on the yield and quality of the roots of witloof chicory. The largest increase in yield was obtained in the first year, in which there was a drought during sprouting and scarcity of rainfall during vegetative growth. In flat-ground cultivation, and in the year with insufficient soil humidity in ridge cultivation, surface irrigation was more beneficial in comparison with subsurface irrigation because it created better conditions in terms of moisture levels, particularly for the germinating seeds. In the years with sufficient rainfall during germination and sprouting no significant differences were found in the yield of chicory roots between surface and subsurface irrigation.

Chicory plants were forced hydroponically in water using a standard nutrient solution. The roots obtained from irrigated plots, as well as those from flatground cultivation, produced significantly longer and tighter chicons. Over the three years of the study, internal browning of the stem, which is a physiological disorder lowering the quality of chicons, occurred only in 2005. It might have been caused by high temperatures during sprouting and high moisture deficiency in the soil during vegetative growth. The use of irrigation significantly reduced the incidence of this phenomenon, especially in flat-ground cultivation.