Dear Susanthi,

You can use the Abbott formula (correcting efficacy % for the natural mortality in the untreated control plots) or the Henderson-Tilton formula (correcting efficacy % for the natural mortality in the untreated control plots + for the non-uniformity of the infestation: precount before treatment).

Kind regards,

Rik

Dear Susanthi,

You can use the Abbott formula (correcting efficacy % for the natural mortality in the untreated control plots) or the Henderson-Tilton formula (correcting efficacy % for the natural mortality in the untreated control plots + for the non-uniformity of the infestation: precount before treatment).

Kind regards,

Rik

Hi,

you should normal data. For this used of arcsinus formul. Also, abbott formul for obtained correct mortality.

hi

I think the researcher wants to calculate the percentage of murder in the field does not know how?

Hi

The Henderson-Tilton's formula should be used to calculate the insects mortality in field conditions.

Please see this link;

http://embakr.tripod.com/ldpline/HhendTelt.htm

The Henderson-Tilton's formula is the suitable way to calculate the insect mortality in the field. The pre-treatment counts recorded before spraying then, the reduction percentages of the treated pest by the treatments were recorded at different time intervals.

For mortality correction in insecticides experiments there are four formula, choosing the appropriate formula depends on the data collected (number of live insects or mortality percentages).

Mortality data in field experiment depends on the tested insects for example in case of insects like aphids you record the number of aphids per leaf or plant before treatment in both control plot and treatment plot, then use Henderson- Tilton’s formula. In case of locust and grasshopper I usually collect individuals from treated and control plot and keep them in field cages and monitor the mortality, then use Schneider-Orelli's formula.

So if you deal with number of live insects or infestation, in such case you could use Abbott or Henderson-Tilton's formula.

If you deal with mortality percentage, you could use either Sun-Shepard or Schneider-Orelli’s formula according to (Püntener 1981):

Please visit the flowing web site for more information

http://www.ehabsoft.com/ldpline/onlinecontrol.htm

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

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

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

Hello, mortality can be calculated as the number of dead insects over the total insect population during chemical application times 100

Thank you Alll

To obtain the mortality of an organism in a biological effectiveness test, the number of live individuals is compared before the application of the pesticide, against the number of living organisms after the application, in an appropriate time interval according to the nature of the pesticide. It is also necessary to have a witness (control) in which no pesticide is applied, since if mortality occurs in it, it will be necessary to perform the mortality correction (Abbott, Handerson Tilton or other); if there is no mortality in the control means that there was no unknown mortality in the pesticide treatment and the mortality data in the pesticide treatment are reliable, that is, the mortality is attributed only to the pesticide. The details of the methodology vary according to the nature of the organism according to its mobility and habits canceled or not, nature of the toxic by the mode of action and efficiency, mainly

Thank you very much

Please visit the flowing web site for more information

http://www.ehabsoft.com/ldpline/onlinecontrol.htm

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

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

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

Hi

Please see this paper.

https://www.researchgate.net/publication/233498446_Evaluating_Single_Treatment_Data_Using_Abbott's_Formula_With_Reference_to_Insecticides

Thank you very much Alireza