Japanese Bulb Onion: Production, Consumption, and Cultivars

Bulb onion is an ancient vegetable crop that has been cultivated for at least 5,000 years. In Japan, this cultivation has only 150 years of history, but nowadays, it ranks fourth in total production, fourth in cropping acreage, and second in consumption among vegetables grown domestically. Until the 1970s, open-pollinated onion cultivars were predominantly cultivated throughout the country; they were selected mainly from old US cultivars. Over the past three decades, these open-pollinated cultivars have been replaced with F1 hybrid cultivars that offer higher yield, better disease resistance, uniformity at maturity, and high bulb quality. In this review, an attempt is made to characterize the commercial production and consumption of Japanese bulb onion as well as agronomic characteristics of representative cultivars.