EFFECT OF PLANTING TIME ON THE GROWTH AND QUALITY OF JAPANESE WHITE RADISH (DAIKON; RAPHANUS SATIVUS L.) GROWN ON THE CENTRAL COAST OF NEW SOUTH WALES, AUSTRALIA

Abstract

Among the Asian vegetables, white radish (Raphanus sativus L.) has become one of the most popular in Australia. With increased interest in exporting produce to Asia, there exists a need for knowledge of growth, postharvest performance and processing technology of this root vegetable. This is a result of one part of a series of research in which the growth and root quality of seven Japanese white radish cultivars were studied in a replicated trial, paying special attention to the development of shoot, root, pithiness, pungency and bolting of the processing cultivars in four different growing seasons (spring, summer, late-summer and autumn) to determine optimum maturity for harvest targets for the dried and pickling industries. Results have shown that the processing cultivars have always achieved a root standard size of 1,000 g at about 5-10 days later than those of fresh market cultivars. The occurrence of pithiness varied among cultivars but was not significantly different between processing and fresh market types. Daikon tended to develop pithiness early in summer and late in autumn. Development of pungency varied among cultivars. Generally, processing cultivars showed a significantly higher level of pungency than those of fresh market cultivars. Flower bud formation (bolting) varied among cultivars but spring and summer plantings showed the highest risk of bolting while the autumn planting showed the least.