Comment on “Effects of 60 Hz electromagnetic fields on early growth in three plant species and a replication of previous results” by Mark S. Davies
✍ Scribed by W.C. Parkinson
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 24 KB
- Volume
- 18
- Category
- Article
- ISSN
- 0197-8462
No coin nor oath required. For personal study only.
✦ Synopsis
In a recent paper Davies [1996] offers data that have a value less than 133 for RE1 and RE2, and less than 181 for RE3 to obtain a P-value ú 0.05. indicate that 60 Hz EMF tuned to the calcium reso-Fourth, in RE2 seven of the ten parameters have nance enhances the growth of Raphanus sativus, and control values larger than the exposed values. In anaappear to replicate the results of Smith et al. [1993].
lysing his data (using the two-tailed t-test for lack of The purpose of this note is to comment both on his sufficient data to do a non-parametric test) six of the data and on his conclusions.
ten parameters in RE1 have P-values less than 0.02, First, this is a surprisingly ''noisy'' experiment.
while for RE2 only two of the ten have values less The ratio of the standard deviations of the mean to the than 0.02, and RE3 five of the ten parameters have Pmeans is large, varying up to 1.52. The mean values values less than 0.02. of the ratio together with their standard deviations for
In view of the ''noisy'' experiment, the fact that the ten parameters in each of runs RE1, RE2, and RE3
for eight of the parameters the control value is larger are 0.55 { 0.42, 0.33 { 0.08, and 0.42 { 0.28 for the than the exposed and that less than half of the P-values exposed plants and 0.37 { 0.10, 0.39 { 0.13, and 0.39 show a significant difference at the 0.02 confidence { 0.15 for the control. level, I would not consider the results reported in Da-Secondly, there is a large variation in the magnivies' paper to ''concisely demonstrate an emf-effect.'' tude of the data between runs RE1, RE2, and RE3. He suggests the variation is due to seasonality, there being