The Korean Journal of Crop Science ISSN:0252-9777(Print) 2287-8432(Online) 한국작물학회지

The purpose of this study was to establish the proper sowing time and planting density of cowpeas for labor-saving cultivation. Experiments were carried out in Naju, Jeonnam Province (Latitude 35° 04' N, Longitude 126° 54' E) during 2012 and 2013. The intermediate-erect type strains used in this study were Jeonnam1 and Jeonnam2. Sowing was performed five times between June 25 and August 5 at approximately 10-day intervals in order to establish proper sowing time, and sowed at 5,000, 10,000, 15,000, and 20,000 plants per 10a to establish proper planting density. The days from sowing to first flowering was shortest (32 days) in plants sowed on July 25 and became longer for plants sowed on or around July 25. The days from sowing to first flowering was longest (41 days) in plants sowed on June 25. The days from first flowering to first maturing was shortest (8 days) in plants sowed on June 25 and, became considerably longer at later sowing dates. The days from first maturing to first harvesting ranged from 8 to 10 days, with little difference among the sowing periods. Plants sowed on August 5 harvested at the same time, and plants sowed between June 25 and July 25 were harvested either three or two times. The yield was highest in plants sowed on July 25: 209 kg/10a was harvested for Jeonnam1 and 221 kg/10a for Jeonnam2. Furthermore, harvested at the same time enabled when the harvesting was delayed for around 15 days because the share of the seeds first harvested was highest (91%). The proper planting density was estimated to be 15,000 plants/10a, showing the highest yields of 199 kg/10a for Jeonnam1 and 224 kg/10a for Jeonnam2.