Abstract
The weed survey for rice cultivation types was conducted to take the basic information of weed control in Honam rice cultivation area of southwest Korea. Twenty-four weed species of 14 families occurred after basic weed control in the machine transplanting rice paddy fields. The highest emergent frequency species was Monochoria vaginalis (Burm. f.) Presl var. plantaginea (Roxb.) of 21.5 percent, and Eleocharis kuroguwai Ohwi, Echinochloa crus-galli and Sagittaria trifolia L. in order was shown high emergent frequency. The ratio of emergent frequency for annual and perennial weeds was about 60 and 40 percent. Fifty-six weed species of 23 families in water seeded rice fields were emerged, the emergent frequency were high with Aneilema keisak Hasskal (10.5 %), Echinochloa crus-galli, Monochoria vaginalis (Burm. f.) Presl var. plantaginea (Roxb.), Lemna aequinoctialisos Hegelm. and Lindernia procumbens (Knock.) Borb. in order. The emergent frequency ratio of annual and perennial weeds was about 87 and 13 percent. Fifty-four weed species of 19 families occurred in direct seeding on dry paddy fields. The highest emergent frequency weed was Echinochloa crus-galli of 10.4 percent and the weeds of high emergent frequency were Eclipta prostrata (L.) L., Ludwigia prostrata Roxb. and Aneilema keisak Hasskal in order. The emergent frequency of annual and perennial weeds was 88 and 12 percent. Weeds occurred in double cropping machine-transplanting paddy fields were thirty-four species of 17 families, and Lindernia procumbens (Knock.) Borb., Monochoria vaginalis (Burm. f.) Presl var. plantaginea (Roxb.), Echinochloa crus-galli, Ludwigia prostrata Roxb., Eleocharis kuroguwai Ohwi and Sagittaria trifolia L. in order were shown high emergent frequency. The ratio of emergent frequency for annual and perennial weeds was 81 and 19 percent