THE INFLUENCE OF SOME FACTORS ON THE KEEPING QUALITY OF ONIONS

For several years the storing of onions has been the topic of our investigations at Skierniewice. Different conditions of storing and keeping quality of various cultivars of onions have been studied (Chroboczek, 1936), then chemical treatment (MH or other substances), and irradiation have been tested to prevent sprouting of the bulbs during storage (Kepka, 1966; Kepka and Majlert, 1961).

In the last three or four years special attention was paid to the conditions of onion growing, as well as the methods of curing onions after harvest, in order to find in that field the methods of improving the keeping quality of onions by natural means. Several experiments have been conducted in the Institute of Vegetable Crops at Skierniewice. The following factors which may influence the yield, the keeping quality of the onions in storage, and their marketable value (especially resistance to cracking of the skin) were studied: fertiliz tion (various doses of N), irrigation, the time and methods of harvest (mechanical or hand), and methods of curing onions after harvest.

On the basis of these experiments the conclusion can be drawn that the adequate stage of maturity of onions at the time of harvest is the most important factor among those mentioned above.