1 Contribution from the All India Coordinated Research Programme on Weed Control, Directorate of Research, University of Agricultural Sciences, GKVK Campus, Bangalere-560 065.
Cucumber root growth bioassay was used for detecting the concentrations of glyphosate (0–4.0 ppm) and butachlor (0–1000 ppm). The reduction in root growth was concentration dependent in both herbicides and it varied from 12. 5′A at 0.5 ppm to 87.5% at 4 ppm in glyphosate and 27.3% at 1 ppm to 40.7% at 1000 ppm in butachlor (48 h after incubation). For detecting the concentration of dicamba (0–10 ppm), root, shoot and hypocotyl growth bioassay of cucumber, greengram and blackgram were used. The presence of dicamba even in low concentration of 0.1 ppm can be detected by using pre-germinated cucumber and blackgram root growth bioassay. Further, hypocotyl radial expansion bioassay of cucumber can be used for detecting the preser.ee of dicamba. The growth suppression was concentration dependent in all the crops. The regression formula and correlation coeffeicients have been worked out.
