As a result of the favourable summer in the Netherlands, with many hours of sun and relatively high temperatures, in early October this year the chicory roots are already better developed and in general have a higher level of ripeness than in other years. The figures for dry matter already average 26-27%, the figures for nitrogen average between 0.6 and 0.9%, and the K/Ca ratio averages between 8 and 10.

More ripeness this year

In addition to the necessary pre-cooling, these lots will also require higher initial temperatures to provide for further activation of the pith, as is usual for new roots. This temperature is required at the beginning of the forcing period - also for somewhat riper roots - in order to develop the pith. Initial water temperatures of between 20-21°C are customary. The air temperature is usually about 2-3°C lower. It may be necessary to maintain a higher air temperature during the first few days, since the growing point responds primarily to the air temperature at the beginning of the forcing period. Begin the nutrient schedule with about 2.2 mmol/L ammonium.

Lower the temperature on time

In order to achieve a well-developed ripeness, the temperature should be lowered on time during the second half of the forcing period so as to maintain control of the pith. If the temperature remains too high for too long, it is possible that the head will reopen. In the second half of the forcing period, use a lower level of ammonium (around 1.5 mmol/L) in the nutrient solution.

Be careful of temperature surges after 10 days. If the pith is activated too late, it will often "push open" the heads.