Abstract
Cichorium intybus is a valuable crop due to its high nutritional and pharmaceutical value. In this work, the study of the effect of harvesting time on the biometric and biochemical properties of Cichorium intybus L. var. foliosum (chicory salad witloof) was carried out on five varieties. The period of vegetation affects rosette diameter, number of leaves and root weight. A strong correlation between the weight of roots before laying for forcing and the weight of forcing heads (r = 0.79) was revealed. The roots of variety Conus, managed to accumulate a sufficient amount of nutrients for the formation of heads in a 98 days. The accumulation of sugars in forcing heads depended on their initial content in roots with a 75% reliability (r = 0.75). The results showed that in the northern latitudes the forcing can be carried out in winter in any room without light at a temperature of 10 to 17°C. In addition, subsurface heating of the substrate or maintaining water in the containers with roots provided a larger yield of heads obtained in a shorter time.