SELECTION OF ASPARAGUS CULTIVARS FOR COLD AREAS OF JAPAN

The aim of this research was to select asparagus (Asparagus officinalis L.) cultivars with high quality, high yield, good day's elongation of spear, high tolerance to diseases, spear head tightness and a good adaptation to cold areas of Japan. The comparative trial, established at Nagano Vegetable and Ornamental Crops Experimental Station, included 17 green cultivars. On a yearly basis the following traits were scored: spear yield, spear head tightness and commercial characteristics of the spear; number, height and size of the stem, weight of the canopy, a day’s elongation of spears, disease tolerance, earliness of spear emergence in the spring. Based on three years of spear yield data and plant characteristics and disease tolerance, the cultivars 'Grande', 'Jersey Giant', 'NJ953', 'Gijnlim' and the Japanese experimental hybrid '0008G2' were considered to be the most promising. 'Gijnlim' showed problems with spear head tightness for summer and autumn harvests.