[article]
Title : |
Probit and Logit analysis: Multiple observations over time at various concentrations of biopesticide Metarhizium anisopliae strain |
Material Type: |
printed text |
Authors: |
T. N. Bhusal, Author ; M. Pokhrel, Author ; R.B Thapa, Author |
Publication Date: |
2020 |
Article on page: |
43-51 p. |
Languages : |
English (eng) |
Keywords: |
Models, Log transformation, regression lines, predictors, LT50, LC50 |
Abstract: |
A study was done to assess the goodness of fit of the regression lines using the data of silkworm larvae (J12 x C12 race) killed
by various concentrations of M. anisopliae and LC71 of Metarhizium. anisopliae at different time intervals (hr) applying
probit and logit function. The data were transformed before analysis using probit and logit transformations of proportion
kill and with and without a logarithmic transformation of predictors. Analysis showed that the LC50 value were 5.969×106
,
6.000×106
, 7.250 and 7.235 spores mL-1 for probit, logit, log-probit and log-logit, respectively. The LT50 values were 204.247,
204.381, 2.304 and 2.305 hr for probit, logit, log-probit and log-logit, respectively. Significant Chi-square value indicates
the necessity of heterogeneity factor for correction of variances under all functions. Residual deviance values were lower
at the log-probit (2.826 for concentration and 0.292 for time) and log-logit (2.406 for concentration and 0.440 for time)
models with higher p-values (≥ 0.587) compared to probit and logit model. In our study, p-values was higher (p>0.05) with
lower residual deviance in log transformed data which indicated that the log-probit and log-logit models could best fit to the
mortality data of silkworm larvae when the both concentration and time were as predictors. Results indicated that the logtransformation of predictors would be best for describing the mortality values of insects by concentration of Metarhizium.
anisopliae and under different time values. However, it requires more précised complete datasets and good knowledge of
statistics of samples values along with the conversion of results of probit and logit analyses back to original units before
coming into concrete application of these analytical inferences into practice. |
Link for e-copy: |
https://afu.edu.np/sites/default/files/Probit%20and%20Logit%20analysis%20Multipl [...] |
in Journal of Agriculture and Forestry University > Volume 4 (2020) . - 43-51 p.
[article] Probit and Logit analysis: Multiple observations over time at various concentrations of biopesticide Metarhizium anisopliae strain [printed text] / T. N. Bhusal, Author ; M. Pokhrel, Author ; R.B Thapa, Author . - 2020 . - 43-51 p. Languages : English ( eng) in Journal of Agriculture and Forestry University > Volume 4 (2020) . - 43-51 p.
Keywords: |
Models, Log transformation, regression lines, predictors, LT50, LC50 |
Abstract: |
A study was done to assess the goodness of fit of the regression lines using the data of silkworm larvae (J12 x C12 race) killed
by various concentrations of M. anisopliae and LC71 of Metarhizium. anisopliae at different time intervals (hr) applying
probit and logit function. The data were transformed before analysis using probit and logit transformations of proportion
kill and with and without a logarithmic transformation of predictors. Analysis showed that the LC50 value were 5.969×106
,
6.000×106
, 7.250 and 7.235 spores mL-1 for probit, logit, log-probit and log-logit, respectively. The LT50 values were 204.247,
204.381, 2.304 and 2.305 hr for probit, logit, log-probit and log-logit, respectively. Significant Chi-square value indicates
the necessity of heterogeneity factor for correction of variances under all functions. Residual deviance values were lower
at the log-probit (2.826 for concentration and 0.292 for time) and log-logit (2.406 for concentration and 0.440 for time)
models with higher p-values (≥ 0.587) compared to probit and logit model. In our study, p-values was higher (p>0.05) with
lower residual deviance in log transformed data which indicated that the log-probit and log-logit models could best fit to the
mortality data of silkworm larvae when the both concentration and time were as predictors. Results indicated that the logtransformation of predictors would be best for describing the mortality values of insects by concentration of Metarhizium.
anisopliae and under different time values. However, it requires more précised complete datasets and good knowledge of
statistics of samples values along with the conversion of results of probit and logit analyses back to original units before
coming into concrete application of these analytical inferences into practice. |
Link for e-copy: |
https://afu.edu.np/sites/default/files/Probit%20and%20Logit%20analysis%20Multipl [...] |
|