IMPROVEMENT OF STORAGE ABILITY IN CABBAGE
Selection pressures on storage ability and seed cabbage quality, in addition to the consumers' demands for cabbage during various seasons, have been the main forces behind the development of the variety groups. Early cabbage, that in this country is harvested 50 to 80 days after planting, seems to have lost its ability to be stored as an edible produce for more than a few weeks. Even autumn cabbage, with a growing season of 80–110 days is suitable only for short-term storage.
Only some winter varieties will keep from October to May. The question then arises how to improve the storage ability in material based on crossbreeds between good keeping varieties and more or less easily perishable individuals. Literature contains little information on this point.
We have carried out a series of such crossings in our efforts to incorporate resistance against the fungus Plasmodiophora brassicae. Original sources of resistance were only found in primitive, easily perishable rural varieties as Böhmerwald. Their rhythm of development was rather unsuited for Norwegian conditions. The plants were easily vernalized, and considering their size the heads were loose and light. In September-October the heads tended to develop glassy infiltrations owing to frost damages, while Norwegian varieties, growing alongside, were left undamaged. After harvesting, the heads decreased rapidly in weight due to loss of water. The leaves were light green and were almost completely lacking wax coating.