(A25)
APPLE: Malus domestica Borkhausen, 'Gala'
CONTROL OF APPLE MAGGOT, 2004
John C. Wise
Department of Entomology
Michigan State University
East Lansing, MI 48824-1115
Phone: (517) 432-2668
Fax: (517) 353-5598
E-mail: [email protected]
Kevin Schoenborn
Larry J. Gut
Apple maggot (AM): Rhagoletis pomonella (Walsh)
The objective of this study was to measure the efficacy of some new insecticides and formulations in the
neonicotinoid class when applied at the normal control timing of AM flight plus 7 d. The test materials were
applied to 12-yr-old 'Gala' apple trees (Gray Block) at the Trevor Nichols Research Complex in Fennville, MI
with an FMC 1029 airblast sprayer calibrated to deliver 100 gpa at 2.5 mph. Single-tree plots were arranged
in a RCB design with four replications. Tree spacing was 18 × 20 ft, with at least one buffer tree and one
buffer row separating all plots. Regular maintenance foliar applications of Kocide 2000, Nova, Flint,
Agrimycin-17, Penncozeb, Vangard, Apogee plus AMS, Mycoshield and Mora-Leaf 20-20-20 were applied
separately to all treatments. In addition, Actara and Confirm were applied for fruit protection when fruitlets
were 8-10 mm diameter, and Sinbar and Glyphomax Plus were banded below the trees for weed control.
Applications of test materials were made on a 14 d interval beginning on 7 Jul, 21 Jul, and 5 Aug. To
evaluate AM infestation, a 1-bushel box of apples (approximately 100 fruit) was picked from each
replicate on 16 Aug. The bushel boxes were inverted and placed on racks over aluminum trays containing
a 1-inch layer of sand. After incubating for five wk at ambient temperature, AM pupae were collected on
23 Sep by sifting the sand through window screen. Data are presented as the mean number of AM pupae
per bushel, and were analyzed using ANOVA and means separation by Duncan’s New MRT at P ≤ 0.05.
All treatments gave significant fruit protection from AM, with Guthion giving the best overall control.
These results show very clearly that the type of formulation of a product can have a significant impact on
the activity of the active ingredient (in this case, imidacloprid) since all of the Provado and NTN33893
treatments were applied at the same rate of AI per acre. There were no statistical differences in
performance among the different formulations of NTN33893 or Provado 1.6F, however, the Provado
75W formulation was outperformed by all imidacloprid formulations except for 1.6F applied alone. It is
interesting to note that the addition of Nu-Film 17 to Provado 1.6F improved its performance to a level
comparable to Assail and Calypso. This would suggest that the activity of the 1.6F formulation against
AM can be enhanced by holding the residue on the plant surface with an extender such as Nu-Film 17.
AM pupae/bushel
Treatment/
formulation
Untreated check
Provado 1.6F
NTN33893 200OD
NTN33893 240OD
NTN33893 192OD
NTN33893 70WG
Provado 75W
Assail 70WP
Guthion 50WSB
Calypso 4F
Provado 1.6F +
Nu-Film 17
Rate
amt product/acre
Application
timinga
16 Augb
--8.0 fl oz
7.68 fl oz
6.4 fl oz
8.0 fl oz
2.28 oz
2.12 oz
3.43 oz
2.0 lb
6.0 oz
8.0 fl oz
1.0 pt/100 gal
--a, b, c
a, b, c
a, b, c
a, b, c
a, b, c
a, b, c
a, b, c
a, b, c
a, b, c
a, b, c
267.5a
60.8bc
27.8cd
31.0cd
42.8cd
52.5bc
87.5b
11.8cd
4.3d
24.8cd
29.0cd
Means within columns followed by same letter do not significantly differ
(Duncan’s New MRT; P > 0.05).
ANOVA performed on square-root transformed data; data presented
are actual counts.
a
a = 7 Jul; b = 21 Jul; c = 5 Aug.
b
Fruit harvested on 16 Aug; pupae collected on 23 Sep.