Investigation of a Suitable Seeding Method and Timing of Thinning to Shorten Thinning Labor on the Direct-Seeded Cabbage Production

Abstract

This study investigated a suitable seeding method and timing of thinning on direct-seeded cabbage cultivation, aiming to shorten thinning labor. We compared a seeding method of sowing two seeds per 10 cm with a conventional seeding method (sowing two seeds), and thinned at two-leaves stage and six-leaves stage, respectively. The thinning time was significantly shorter in 10-cm seeding (2.0–3.1 s/hill) than in conventional seeding (4.7–4.9 s/hill), suggesting that the proposed seeding method was suitable to save thinning labor. In 10-cm seeding, thinning time at six-leaves stage was 1.1 s/hill shorter than that at two-leaves stage. The cabbage growth (leaf area and cabbage head weight) was not significantly affected by the timing of thinning, but the growth tended to be better in 10-cm seeding than in 0-cm seeding. These indicated that 10-cm seeding with thinned at six-leaves stage would be suitable for saving thinning labor and achieving a robust direct-seeded cabbage production.