This study was investigated to find the effects of sowing time on growth and yields of cowpea grown in a southern region of South Korea. Experiments were carried out in Naju, Jeonnam Province (Latitude 35° 04' N, Longitude 126° 54' E) during 2013 and 2014. The intermediate-erect type strains used in this study were Jeonnam1 and Jeonnam2 (Okdang). Sowing time was performed between middle-April and middle-August at intervals of one month. The days from sowing to emergence was significantly higher in the middle-April sowing (12 days) time but there was no significant differences other sowing dates (5 to 3 days). The days from sowing to first flowering were shorter for sowing dates between middle-April and middle-July because sowing time was delayed and then were lengthened again at middle-August sowing; the days were longest at middle-April sowing (around 62 days) and were shortest at middle-July sowing (35 days). The days from first flowering to harvesting were short for the sowing dates between middle-April and middle-July (17 to 15 days) but were relatively long for middle-August sowing date (24 days). Stem length was relatively long for the middle-May and middle-June sowing dates. Peduncle length was relatively long for the middle-April sowing date. Main-stem node number was highest for the middle-July sowing. Branch number per plant was highest in the middle-April sowing. Seed yields were highest for the middle-April sown Jeonnam1 and the Jeonnam2 (Okdang) strains showing, 199 and 211 kg/10a, respectively, and then followed by sowing in middle-July, 191 and 195 kg/10a, respectively.

본 연구는 하우스에서 반유한 직립형 동부 계통의 파종기 이동이 생태반응과 생육 및 수량성에 미치는 영향을 구명하 고자 전남 나주(위도 35° 04'N, 경도 126° 54'E)에서 2012 년과 2013년에 수행하였다. 시험계통으로 전남1호와 전남2 호를 이용하여 3월 중순부터 8월 중순까지 1개월 간격으로 6회 파종하였다. 1. 출현일수는 3월 중순 파종에서 12일로 길었고, 기타 파종기에서는 4~3일 이었다. 2. 개화일수는 3월 중순부터 7월 중순까지는 파종기가 지연됨에 따라 짧아지다 8월 중순 파종에서 길어졌다. 즉, 3월 중순 파종에서 75일 내외로 가장 길었고, 7월 중순 파종에서 30일로 가장 짧았다. 3. 개화시에서 수확기까지의 소요일수는 3월 중순부터 5 월 중순 파종에서 28~24일로 짧았으나, 이후 파종에서 는 38~35일로 긴 편이었다. 4. 경장과 화경장은 4월 중순과 8월 중순 파종에서 긴 편 이었고, 주경절수는 6월 중순 파종, 분지수는 3월 중순 파종에서 많았다. 5. 3월 중순 파종에서는 주당 꼬투리수가 많고 립중이 무 거워, 전남1호와 전남2호의 10a당 수량이 각각 340, 367kg로 가장 많았으며, 이후 파종이 지연됨에 따라 대체로 수량이 감소하는 경향이었다.

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.