Tohoku Agricultural Research Center, NARO

Leaf and Root Vegetable Production Group

The Leaf and Root Vegetable Production Group focuses on the development of new cultivation systems of open-field vegetables adaptable to the climate condition in the Tohoku region such as a low cost and high quality vegetable production system for commercial and processing uses that can be introduced into large-scale paddy farming system.

There is an increasing demand for introduction of highly profitable vegetable production for land-extensive farming in the Tohoku region particularly for cultivation of onion and cabbage. These vegetables have high demands throughout the year and the production is more mechanized than other vegetables. In Japan, the lean season for fresh onions is from July to August, after the harvesting period in the Kyushu region before that in the Hokkaido region, two major onion-producing areas in Japan. This period actually overlaps with the harvesting period of fresh onions sown in the early spring in the Tohoku region, when the onion price stays stable and relatively high. On the other hand, onion seeds in the standard cultivation system in the Tohoku region are sown in the fall and the fresh onions are harvested in the spring, in spite of the unstable productivity caused by the fluctuating winter survival rate to be overcome. The use of both cultivation systems is expected to decrease the running cost of equipments. Thus, we are pursuing research for spreading spring-sowing onion cultivation in the Tohoku region, collaborating with public agricultural research centers, university and seed companies, with which we also investigate the way to control onion bulb rot disease. In addition to the cultivation systems, we investigate the effect of environmental factors on bulb enlargement from early development to maturity to help establish the dual cultivation system in the Tohoku region.

In our cabbage studies, we are developing the cultivation system to ship the products from autumn to winter taking full advantage of the mild climate in winter in the Pacific Ocean coastal areas of the Tohoku region, harvesting by machine with the suitable cultivars. The main stem inclination decreases the machine harvest efficiency of cabbage heads. As the inclination appears to depend on the cultivar and the planing depth, we elucidate the mechanism by comparing cultivars planted at different soil depth.

The application of phosphate solution before planting, whichever by immersing or spraying, is a useful cultivation technique for the low-cost and high-quality production of bunching onions. Because phosphate rock resources for fertilizers will be exhaustible, cultivation systems with reduced phosphate consumption is required urgently. We revealed that an application of 1% phosphate potash liquid fertilizer to the seedlings before planting is capable of 25-50% reduction. From now on, we are trying to apply this technique for onion production.

Peak growth period of spring sown onion

Group Leader

MURO Takato

Group Members

Centers・Institutes