Effect of different irrigation levels on quality and storability of kohlrabi (Brassica oleracea var. gongylodes,L.)

This investigation was conducted at the Faculty of Agriculture, AL-Azhar University, Nasr City, Cairo, Egypt during the two winter seasons of 2012-2013 and 2013-2014 to study the effect of different irrigation levels (100,75and 50% from crop evapotranspiration) on quality of the kohlrabi tuber of the hybrid Grand Duke and its behavior during cold storage at 5c° and 90-95% RH or under the conditions of room temperature at ± 2 c° and 55-58%RH. The results indicated that the highest significant tuber fresh weight, size, diameter and total yield resulted from the irrigation with the level of 100% from Etc and the greatest significant solidness was obtained from the level 50%. From the chemical point of view, the tuber contents of total soluble solids, ascorbic acid and total acidity increased with the decrease in the irrigation levels up to 50% as compared with the level 100%. On the other hand, storage of the kohlrabi tubers showed that the minimum loss in weight and the unmarketable percentage were found in the irrigation level of 100% from Etc during the final storage periods of cold and room temperature storage at the same time irrigation of 50% hold the higher concentrations of T.S.S, ascorbic acid and total acidity in the stored tubers during storage periods in the two sort of storage with the prevalence of cold storage. Therefore, cold storage was the most obvious in retaining tuber quality much better than those stored under room temperature.