ISSN:
1365-3180
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
In a collaborative study by 12 laboratories the reproducibility of bioassay techniques was analysed by comparison and statistical treatment of the ED50-values (μg herbicide/g soil). Commonlyused bioassay techniques were investigated; two direct seeding methods, a transplanting method and a shoot extension method. The herbicides studied were two photosynthesis inhibitors, atrazine and metribuzin using Lepidium sativum and Brassica rapa as test plants; two germination inhibitors, tri-allate and trifluralin using Avena sativa as test plant. The mean ED50-value of atrazine in the direct seeding method was 0.18 with a variation from 0.12 to 0.29 and 0.12 (0.07–0.68) in the transplanting method. The values of metribuzin were 0.05 (0.02–0.11) and 0.03 (0.01–0.15) respectively. The values for triallate were 1.15 (0.50–2.60) in the direct seeding method and 1.10 (0.54–2.53) in the shoot extension method and for trifluralin 3.11 (0.72–18.31) and 1.33 (0.48–2.94) respectively. The reproducibility was best in the shoot extension method. No outliers (confidence intervals lying entirely outside the confidence interval of the overall mean) in the ED50-values were observed with atrazine and metribuzin when using the direct seeding method, whereas with the germination inhibitors a high number of results (four with tri-allate, six with trifluralin) could be considered as outliers. A comparison of the use of fresh weight and dry matter showed good agreement between the ED50-values they gave, with similar reproducibility.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-3180.1982.tb00166.x
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