Chemistry Reference
In-Depth Information
leaves with no insecticide only on 28 May and 7 Jun, but not on 17, 17 Jun or 7 Jul. Leaves
from dinotefuran-treated potato plants under the high rainfall regimen showed no
significant differences for damage as compared with the leaves with no insecticide on all
dates of the bioassay (Fig. 2).
3.2. Field results
The results of the ANOVA to test the main effects (amount of simulated rainfall and
insecticide) and rainfall by insecticide interaction on CPB and PLH in field trials are
summarized in Table 2. ANOVA demonstrated significant (P<0.01) insecticide (sub-plots)
effects for all data (total CPB, CPB defoliation and PLH damage rating). The main effect of
the amount of simulated rainfall was significant (P<0.05) only for PLH damage. A significant
(P<0.05) interaction of the amount of simulated rainfall by insecticide was observed for both
the percentage defoliation caused by CPB and for PLH damage.
PLH damage rating
(0-5 scale)
No. CPB/3 hills
% CPB defoliation
6/1
6/11
6/17
6/1
6/11
6/17
6/25
6/25
7/3
MP
SP
MPxSP
ns
**
ns
ns
**
ns
ns
**
ns
ns
**
*
ns
**
*
ns
**
*
ns
**
ns
**
**
*
**
**
*
MP= main effect of simulated rainfall; SP= main effect of insecticides; MPxSP= interaction
1
Summary of results of analysis of variance. ns= nonsignificant; *, P<0.05%, **, P<0.01%
Table 2.
Summary of effects of simulated rainfall and insecticides on control of Colorado potato beetle
(CPB) and potato leafhopper (PLH) on potatoes in field trials
1
, Bridgeton, NJ 2007
Plots treated with either imidacloprid or thiamethoxam had fewer CPB larvae on all dates
recorded as compared with plots that received no insecticide in both the high and low
rainfall regimens; the number of CPB larvae/3 hills recorded in plots treated with
imidacloprid or thiamethoxam remained low throughout the season (Fig. 3
)
. The plots
treated with dinotefuran had significantly (P<0.05) more CPB larvae then did either of the
plots treated with either imidacloprid or thiamethoxam on 17 Jun. There were no significant
(P<0.05) differences between plots treated with dinotefuran and plots that received no
insecticide for number of CPB larvae/3 hills in either the low or high rainfall regimen on
each day observed throughout the season. Both imidacloprid and thiamethoxam were
effective in reducing the numbers of CPB larvae throughout the season (from planting
through late Jun). Under the low rainfall regimen, dinotefuran was effective in reducing
CPB larvae only through early Jun, and under the high rainfall regimen the number of CPB
larvae/3 hills for potato plants treated with dinotefuran was not significantly (P<0.05)
different than plants that received no insecticide on any date observed.
