It seems like quality
fruit must be sprayed at the recommended intervals.
Starting with dormant oils, these need to be applied before buds
swell. Dormant oils are usually needed only every two or three
years to provide control of scales and mites. Sure, the
populations will build up in the off years, but should remain
relatively low if the three-year program is followed. Dormant
oils do require temperatures above freezing for 24 hours, but
you want to be ahead of the bud swell.
The first regular spray of the year is applied when the green
tissue is a half-inch out of the bud. The spray
homeowners use usually consists of a multipurpose fruit spray
(and sulfur if needed for powdery mildew). Multipurpose
fruit spray has been reformulated the last few years to include
malathion, captan and carbaryl (methoxychlor was eliminated from
the old mixture). This same mixture would be used when
the fruit buds are in the pink stage (when fruit buds show
color). After that, the persistence and consistency pays
off as you spray with the same mixture about every 10 days until
we get to within two weeks of harvest. In our area, we
need to continue spraying this late because of apple maggot and
This spray program will also control borers on apples and
pears, if you also thoroughly spray the trunk and main limbs of
the trees. On non-bearing, young fruit trees where borers
have attacked, you can spray the trunks every two weeks during
June and July with a multipurpose fruit spray.
The spray schedule for peaches, nectarines, apricots and
plums varies a little bit. The dormant spray for them
uses captan fungicide. This is the only spray that
controls leaf curl and plum pockets. The next spray is
with captan when fruit buds show color, followed by captan at
bloom. When the husks begin to pull away from the base of
the fruit, we would then spray with sulfur, captan and malathion.
This mix would then be used every 10 days or so to within a
week of harvest.
For borers on the peach group, you can spray or paint the
trunk only with carbaryl (Sevin) on June 15, July 15 and Aug.
15. We have some challenges with the loss of some of the
insecticides, since carbaryl can cause fruit drop or thinning on
the peach group and some apples.
[to top of second column]
Adult Japanese beetle control
Application of imidacloprid (Merit and other brand names) and
other systemic insecticides is effective in controlling Japanese
beetle adults. Although the imidacloprid occasionally doesnít work
in a tree to control this pest, it does over 80 percent of the time.
However, a soil application of imidacloprid typically takes six to
eight weeks to move completely up to the leaves of large trees. With
Japanese beetle emergence typically starting the fourth week of June
in our area, the sooner the better for application. This would be a
prime option for linden trees, crab apples, rosebushes and other
favorites of the Japanese beetle.
Imidacloprid can be soil-applied either as a drench or by
injection. Because imidacloprid is easily tied up on organic matter,
mulch and other dead organic matter must be removed from around the
base of the tree before a drench application is made. Removal of
turf around the tree would also be recommended for a drench. Soil
injections should be made deep enough to get below mulch, turf
thatch and other organic matter, but not deeper than 3 to 4 inches.
Apply to the soil within 1 to 2 feet of the trunk, where the
greatest concentration of fine feeder roots is located.
Just remember, each beetle must eat some leaf to get the
insecticide. If a million beetles all take two bites of your linden
leaves, there are still going to be a lot of leaves eaten. Donít use
this treatment on fruit or small fruit trees unless labeled
University of Illinois Extension, Logan County]