Software to calculate probit analyses according to Finney (1971), Which is used to illustrate the relation between stimulus and response in toxicological and biological studies. Illustrate dose-response regression line

Control correction

In this page, you can calculate corrected efficacy % according to Abbott, Henderson & Tilton, Schneider-Orelli or Sun-Shepard formulas.

• There are 4 formulas available to calculate corrected efficacy % in pesticide trials.

• The selection of appropriate formula is depending on two factors:
1-Trial condition (infestation or population stability and homogeneity).
2-The data in your hand (live individuals or mortality %).

 Available data Non-uniform population Uniform population Infestation or live individuals Henderson-Tilton Abbott Mortality Sun-Shepard Schneider-Orelli

Henderson-Tilton's formula

Corrected % = (1 -

 n in Co before treatment * n in T after treatment n in Co after treatment * n in T before treatment
) * 100
 Where : n = Insect population , T = treated , Co = control

 Population in treated plot before treatment Population in treated plot after treatment Population in control plot before treatment Population in control plot after treatment

Reference:
Henderson, C.F. and E. W. Tilton, 1955.  Tests with acaricides against the brow wheat mite, J. Econ. Entomol. 48:157-161.

Abbott's formula

Corrected % = (1 -
 n in T after treatment n in Co after treatment
) * 100
 Where : n = Insect population , T = treated , Co = control

 Population in treated plot after treatment Population in control plot after treatment

Reference:
Abbott, W.S. (1925). A method of computing the effectiveness of an insecticide. J. Econ. Entomol.; 18 : 265-267.

Sun-Shepard's formula

Corrected % = (
 Mortality % in treated plot + Change % in control plot population 100 + Change % in control plot population
) * 100

 Mortality % in treated plot Change % in control plot

Change % in control plot population = (
 Population in control plot after treatment - Population in control plot befor treatment Population in control plot befor treatment
) * 100

Reference:
Püntener W., 1981 Manual for field trials in plant protection second edition. Agricultural Division, Ciba-Geigy Limited.

Schneider-Orelli's formula

Corrected % = (
 Mortality % in treated plot - Mortality % in control plot 100 - Mortality % in control plot
) * 100

 Mortality % in treated plot Mortality % in control plot

Reference:
Püntener W., 1981 Manual for field trials in plant protection second edition. Agricultural Division, Ciba-Geigy Limited.