Midwest Tree Fruit Spray Guide - Iowa State University Extension ...

In the Midwest, two applications of Apogee at 10 to 12 oz
per 100 gal should be sufficient for preventing fire blight
spread in the summer, but overly vigorous trees may
need a third application (see label).
Additives. The nonionic surfactant Regulaid should be
used with Apogee. Follow the manufacturer’s rate
recommendations. If Apogee is applied in hard water
(water that contains high levels of calcium carbonate),
1 lb of spray-grade ammonium sulfate should be used
for each pound of Apogee.
Comments. Growth control with Apogee is not concentration
dependent. There is no difference in shoot
growth control between dilute and concentrate sprays,
provided the total amount of chemical per acre is the
same. The level of growth control with Apogee is rate
dependent. The greatest and quickest reduction is
obtained at the recommended rate, and the effect on
growth declines as the rate is reduced.
Insecticide Resistance in Codling Moth Populations
Codling moth populations that are suspected or
confirmed to be resistant to certain insecticides have
been reported from several states, including those
covered by this spray guide. The resistance traits of
populations differ among orchards and regions, so
resistance may account for control failures in some
orchards even though the same insecticides may
provide effective control at another location.
Resistance is not the only cause for control failures,
so growers are always urged to consider whether
or not inadequate rates, inadequate spray volume,
spray timing, or wash-off due to rainfall may have
contributed to poor control. Where these factors do
not appear to provide an explanation for control failures,
then resistance, particularly to the organophosphates
(Guthion, Imidan, Diazinon), may be the reason, and
switching to other insecticides is recommended.
Where control programs have been effective and
resistance does not seem to be a problem, rotating
among insecticides with different modes of action is
recommended to delay development of resistance.
(See mode of action groups on page 19.)
Populations that are resistant to the organophosphates
exhibit resistance to all the organophosphates that are
labeled for codling moth control in apples (Diazinon,
Imidan, and Guthion), so switching among these
insecticides offers no benefit. Laboratory research and
field observations have shown that organophosphateresistant
codling moth populations also are less
susceptible to some pyrethroids, so switching to Pounce
(or other permethrin formulations), Asana, Warrior,
Dantol, Baythroid, or Proaxis may not provide adequate
control. The neonicotinoids Assail, Calypso, and Clutch,
as well as the insect growth regulator Rimon, are
effective against organophosphate-resistant codling
moth populations. Growers are urged to consult with
their state extension specialists in entomology to plan
effective season-long programs that make the best use
of available products within the label-specified limits and
restrictions for each.
Mating Disruption for Codling Moth Control
Isomate C-Plus, No-Mate CM, and CheckMate CM
dispensers are registered for control of codling moth.
They dispense the sex attractant of the codling moth
and are designed to prevent male moths from locating
females for mating. Sprayable formulations also are
available. This strategy, termed mating disruption, is
most likely to succeed in blocks of at least 5 acres where
initial populations of codling moth are low. If mating
disruption is used for codling moth control in smaller
blocks or where infestations are greater, border sprays,
or at least one or two cover sprays, also will be necessary.
Controlling codling moth by mating disruption
will not control other insect pests that are controlled
by cover sprays (plum curculio and apple maggots,
for example).
Apple Borers
The dogwood borer and American plum borer are
caterpillars that attack burrknot tissue on apple trunks.
Flat-headed and round-headed apple borers are beetle
larvae that attack tree trunks, often in association with
mechanical or other injury or generally weakened trees.
Any of these borers can be treated with Lorsban
Advanced at a rate of 1.5 qt per 100 gallons of spray,
Lorsban 50 W at a rate of 3 lb per acre or Lorsban 4E
at a rate of 1.5 qt per 100 gallons of spray no later than
28 days before harvest. For dogwood borer, the best
insecticide timing is at peak egg hatch, which is in late
June in the central Midwest. For American plum borer,
the best timing is at petal fall. For flat-headed and
round-headed apple borers, apply insecticide in the
spring. Apply borer sprays to the lower 4 feet of the
trunk and lower branches, soaking the bark. DO
NOT apply Lorsban to the fruit or foliage. Only one
application of Lorsban of any formulation is allowed
each year. Do not use for borers if already used prebloom.
Periodical Cicadas
Periodical cicadas are orange to black, about 1 1 ⁄2 inches
long, with black transparent wings, and appear from
May to July. Annual or dog-day cicadas are larger, green
to black, and appear each year from July to September.
Ordinarily, annual cicadas do not cause much damage.
Cicada males announce their presence to the voiceless
females by making a continuous, high-pitched shrill
sound. Vibrating membranes on the underside of the
first abdominal segment produce the sound.
The total life cycle of the periodical cicada takes either
13 or 17 years. Otherwise, the two types have similar
habits. The adult females lay eggs in rows in pockets that
they cut in small branches and twigs of trees with their
long, knife-like egg layer. Each female will make five to
20 of these pockets, laying 24 to 28 eggs in two rows in
each pocket. The eggs hatch in six or seven weeks; the
21 MIDWEST FRUIT TREE SPRAY GUIDE