Chinese Cabbage Brassica Rapa Vars Pekinensis And Chinensis

Chinese cabbage responds to inductive temperatures from germination; apparently there is no juvenile stage, with flower initials forming when 'vernalization' is completed. Minimum plant raising temperatures of 18°C are required in order to reduce bolting in the field. The growing point height is determined at or before transplanting. A linear model incorporating temperature and solar radiation describes subsequent extension of the growing point.

The processes of 'vernalization' and growing point extension are controlled separately. It is known that stem elongation can occur without flower formation. The influence of solar radiation varies with genotype, for example being greater in the bolting-susceptible cv. Jade Pagoda and less in cv. Kasumi, although temperature has similar effects on both cultivars. Bolting is encouraged by long days. Head development and flower stalk extension appear to be separate processes. The former is driven predominantly by temperature and the latter by temperature subject to an upper maximum and solar radiation (Wurr et al., 1996).

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