Abstract
This study was conducted to establish standard fresh weight data about the minimum amount of occurred weeds at untreated paddy fields, upland fields and orchard fields (including non-cultivated land) in 10 areas. The amount of occurred weeds in each area was compared fresh weight with dry weight. The average percentage for ratio of dry weight to fresh weight in paddy fields was concluded to be 14.8% of Echinochola crus-galli, 12.5% of annual weeds (including Echinochola crus-galli), and 13.9% of perennial weeds. The average percentage for ratio of dry weight to fresh weight in upland fields was concluded to be 20.1% of annual weeds and in orchard fields was concluded to be 18.4% of annual and perennial weeds. According to the research, standard fresh weight about the minimum amount of occurred weeds at untreated paddy fields was proposed to 210 g m-2 of Echinochola crus-galli, 400 g m-2 of annual weeds (including Echinochola crus-galli), and 220 g m-2 of perennial weeds. Standard fresh weight about the minimum amount of occurred weeds at untreated upland fields was proposed to 250 g m-2 of annual weeds and at untreated orchard fields was proposed to 550 g m-2 of annual and perennial weeds.
Acknowledgements
This study was supported by joint research project from Herbicide Research Association (Bayer Crop Science, Farm Hannong, Sungbo Chemical Co. Ltd., Kyungnong Co. Ltd., Korea Bio-safety Institute Co. Ltd., Bio-Plant Environment Research Center Co. Ltd., Enbio Co. Ltd., Applied Biology Research Institute).
Figures & Tables
Fig. 1. Weeds sampled in paddy fields. A: Echinochola crus-galli; B: Monochoria vaginalis; C: Aneilema keisak; D: Aeschynomene indica; E: Cyperus difformis; F: Eleocharis kuroguwai; G: Scirpus juncoides; H: Sagittaria trifolia.
