| Synergistic effects of Azadirachtin and Fanvarlit on larval stage of Spodoptera exigua |
| Paper ID : 1178-3IICE (R1) |
| Authors: |
|
hajar sharghi *, Shahla Karimi, Davoud Mohammadi, Naser Eivazian ary Department of Plant Protection, Faculty of Agriculture, Azarbaijan Shahid Madani University, Tabriz, IRAN |
| Abstract: |
| Beet Armyworm, Spodoptera exigua, is among the key pests of crop plants in Iran. In order to find more eco-friendly controlling method, in a series of experiments we tested the combination effects of Azadirachtin and Fanvarlit on 1st instar larvae Azadirachtin was applied at two concentrations including 50 and 100 ppm in experiments and Fanvarlit concentrations were 25, 50 and 100 ppm. All experiments were conducted using 24-well plate as a replication. The larvae were exposed to treatments by feeding on artificial food mixed with respective concentrations of pesticides. Mortality data were subjected to analysis of variance followed by Duncan's multiple range test. In the combined treatments synergistic, additive or antagonistic interactions on PTM mortality were determined using a 2 test with the control-corrected data. The expected additive proportional mortality ME for the Azadirachtin-Fanvarlit combinations was calculated by ME = MN + MC (1 - MN), where MN and MC are the observed proportional mortalities. Results from a 2 test, 2 = (MNC- ME)2/ME, were compared to the 2 table value for 1 df. If the calculated 2 value exceeded the table value, a non-additive effect was suspected between the two agents. If the difference of MNC- ME had a positive value, a significant interaction was considered synergistic and If negative value, a significant interaction was considered antagonistic. In contrast, if the tabulated value exceeds the calculated 2 value, it represents an additive effect at P < 0.05. After 72 h. Fanvarlit concentrations of 50 and 100 ppm caused 5 and 20% mortalities on larvae. After exposing to Azadirachtin, 25, 35 and 45% mortalities were recorded at 25, 50 and 100 ppm, respectively. The results were synergistic for all combinations of 100 pp Fanvarlit+ Azadirachtin, however, it was antagonistic effect for all 50 pp Fanvarlit+ Azadirachtin treatments. Similarly, synergistic effects were recorded as 37.5, 37.5 and 57.5 for 100 ppm Fanvarlit+100 ppm Azadirachtin for all recording days (one day interval up to three days). These were significantly higher than the assigned values to 100 ppm Fanvarlit+50 or 25 ppm Azadirachtin combinations. The results showed that the combination of Fanvarlit and Azadirachtin have potential for the control Spodoptera exigua compared to single usage of each product and could help reduce the usage of synthetic insecticides in pest management. Nevertheless, complementary greenhouse and field tests are proposed for further understanding of the performance of combined plant protection material against Spodoptera exigua. |
| Keywords: |
| Antagonistic, Azadirachtin; Beet Armyworm; Fanvarlit; Synergistic |
| Status : Paper Accepted (Poster Presentation) |
