벼 낙수시기 기준 자운영 파종적기 구명

An Optimum Seed Planting Time of Chinese Milk Vetch (Astragalus sinicus L.) for Stable Seedling Establishment and Dry Matter Production in Paddy Field

Sufficient seedling establishment of Chinese milk vetch (CMV) is the most important factor in the CMV cultivation. In order to obtain sufficient seedling stand, CMV seed should be planted at right seed planting date. An opti-mum CMV seed planting time for stable seedling establish-ment was determined based on the final water drainage time for rice harvest in fall. Five planting times from 10 days before water drainage (DBWD) to 15 days after water drainage (DAWD) at five day interval were evaluated during the period of 2006-2007 and 2007-2008 and the optimum CMV seed planting time was determined based on seedling stand, winter survival rate, and dry matter production. CMV seedling stand before winter was high with 575~1,050 plants/m2 regardless of seed planting times but after overwintering, it was greater in seed planting date between 5 DBWD to 5 DAWD than that of 10 to 15 DAWD treatments. Winter survival rate, dry matter production and seed production yield also showed similar trend to the seedling establish-ment. On the other hand, when CMV seeds were sowed early at 10 DBWD, seedling stand and winter survival rate were lower than that of 5 DBWD to 5 DAWD. This result in-dicates that an optimum CMV seed planting time based on the final water drainage could be between 5 DBWD (September 20) to 5 DAWD (September 30).