Effect of day and night temperature at different stages of growth on bolting in Chinese cabbage

Abstract

The effect of different temperature conditions in the raising period and after the transplanting stage on bolting in Chinese cabbage has been investigated. It was found that the daily mean temperature in the raising period should, in the case of heat-sensitive cultivars, be above 18°C in order to avoid premature bolting. Energy consumption during the raising period may be reduced by using high day temperatures in combination with low night temperatures. Covering the plants with plastic after transplanting in the field reduced the risk of premature bolting. With the heat-sensitive ‘Nagaoka 50’, a raising period of 4 weeks at 18°C was sufficient to prevent premature bolting under normal field conditions in April–May. The optimal raising temperature is above 24°C for the heat-tolerant ‘Saladeer’. The development of the flower stalk after the transplanting stage is dependent on factors such as daily mean temperature, stage of growth and cultivar.