Island Apple IPM
- Current Pest Report -
Tree stage for McIntosh
4/5/04 - Silver tip
4/13/04 - Green tip
4/18/04 - Half inch green
4/26/04 - Tight cluster
5/1/04 - Pink
5/2/04 - King bloom
5/5/04 - Full bloom
5/12/04 - Petal fall
5/13/04 - Petal fall North Kingstown, 5/17/04 - Petal fall Newport
8/11/04 - Sorry for the the lack of comments. I still don't have time
to write. Do check the apple maggot fly chart.
We are still catching lots of apple maggots.
I'm catching lots of apple maggot flies, particularly in orchards where
an apple maggot insecticide has not yet been applied. See
chart. If it's been more than 2 weeks since your last insecticide
application, it's time to apply one now. Use half rates of Imidan or Guthion.
- I'm finding rose leafhopper in more orchards now. They are present as
small nymphs, large nymphs and adults (the ones that fly). The nymphs
remain on the underside of leaves until they advance to adults. Leafhoppers
are rather easy to control with the proper insecticide. Use Provado, Thiodan,
or Sevin. Provado or Thiodan is less harmful to mite predators than Sevin.
- Green apple aphids are nearly gone in all orchards. Thank you aphid
- More orchards have needed mites controlled this year than in the last
few years. Miticides have been very effective controlling European red
mites and yellow mites. I have not seen any large populations of two-spotted
spider mites this year. Growers have been getting good results with Acramite,
Zeal and Nexter. If you use Acramite, it is recommended to add a spray
adjuvant such as Silwet, Silgard 309, or Kinetic.
- This humid weather is ideal for sooty blotch and fly speck growth. Keep
up with your fungicide applications. Topsin M is a good fungicide for
controlling fly speck and sooty blotch. Flint and Sovran are also excellent
fungicides against these summer diseases. Sovran has a 30 day preharvest
interval; Flint has a 14 day preharvest interval.
I caught a few more apple maggot flies yesterday. We are at the threshold
of 2 AMF/trap in 2 out of 10 monitored orchards and close to the threshold
in several other orchards. After today's rain would be a good time to
apply your first apple maggot fly spray. Use a half rate of Imidan or
- I saw many fewer green apple aphids yesterday than I did last week.
The predators have really started controlling even the largest infestation.
There is a whole assortment of predators out there!
- I found more rose leafhopper nymphs yesterday. They are still rather
small and difficult to see. Look on the underside of newer leaves for
the small, white nymphs. The nymphs can be controlled now with Provado
- I also found some more potato leafhoppers. As I said before, potato
leafhoppers are only a problem on young trees where you want as much growth
as possible. The bright green to yellow nymphs cause the leaves to cup
up and the leaves look mottled - large angular sections of a leaf become
off colored and then brown. Leaf edges become brown as well. Hopefully
potato leafhoppers will be controlled by Imidan or Guthion, but you may
need to use Provado, Thiodan or Sevin to control them adequately.
- Yesterday I definately saw some red spots on apples caused by San Jose
Scale. It is probably too late now to effectively control San Jose scale
this year. It is best to attack them next year with early applications
of dormant oil. The best time to apply oil to control San Jose scale is
at half inch green.
- Mites have been quite numerous this season. Perhaps the harsh winter
killed off too many mite predators causing mite outbreaks this season.
The primary pest has been European red mites, but I've also found two
spotted spider mites and yellow mites. Many trees have been bronzed by
European red mite feeding. It is best to control mites before they cause
significant damage. Several miticides have been very effective, but you
need to check the label for preharvest intervals. Zeal has a 28 day phi,
Nexter has a 25 day phi. Acramite has only a 7 day phi. One grower did
use Vendex and did not get satisfactory results.
- Keep to your 2-3 week schedule for fungicides. Since you'll probably
be spraying with an insecticide in another 2 weeks for apple maggot, it
makes sense to me to use Captan this time and not add the Topsin M. Add
Topsin M when you plan on going three weeks between spray applications.
And, always use Topsin M on your final spray of the season.
7/10/04 - I
caught more apple maggot flies towards the end of the week. We reached
the threshold of 2 AMF per trap at 2 orchards. See
chart. Many growers have begun spraying half rates of Imidan against
- Apple blotch leafminer second generation sap feeding mines can now be
found on the underside of leaves. If you intend to spray for this pest,
consider applying Provado or Calypso now and again in about 10 days.
- Green apple aphids are beginning to disappear in orchards where the
predator population has been high.
7/7/04 - I
have caught a few apple maggot flies on red sticky spheres in two orchards.
Trap captures are below the threshold of 2 AMF per trap. It is still a
little early to apply insecticides against AMF. Usually the first insecticide
is not needed until around July 15-20, but I'll let you know what I find
on the traps. When you do spray for AMF, half rates of Imidan work well.
- I started finding potato leafhopper adults and tiny nymphs this past
week. I distinguish potato leafhopper nymphs from other leafhopper nymphs
by their color and speed. The potato leafhoppers are quite green while
the white apple leafhoppers and rose leafhopper nymphs are white or cream
colored. Also, potato leafhopper nymphs move very quickly when touched
and disturbed. Potato leafhoppers should be controlled on young trees
because potato leafhopper feeding stunts tree growth. On mature trees,
we don't worry about tree growth being stunted (we like stunted growth!)
- I've also started finding rose leafhopper nymphs in a few orchards.
A good time to spray for rose leafhopper will probably be aroung July
15. We don't have a good threshold for leafhopper spraying - but use a
threshold of 25 nymphs per 100 leaves. Rose leafhoppers will not be controlled
with Imidan or Guthion. It is best to use Provado, Calypso or Thiodan.
Sevin also controls leafhoppers but is more harmful to predatory mites.
European red mites are building in some orchards. Growers have had excellent
results using miticides this year. If your trees exceed the threshold
of 2.5 mites per leaf or more than 54% of leaves have mites, consider
applying Zeal, Nexter, or Acramite.
- Leafminer adults are emerging now. Some have probably started laying
eggs for the second generation. If you find more than 13 mines out of
100 fruit cluster leaves, consider applying Provado or Calypso against
the second generation mines. The timing for this spray will probably be
around July 10 and then again about July 17.
- I still have not seen any potato leafhoppers this season. Be sure to
check young trees for leafhoppers. Check new growth for the small, pale
leafhoppers and spray young trees if you find them. Generally potato leafhoppers
can be controlled with Imidan, but sometimes it is necessary to spray
Thiodan, Provado or Sevin.
- I see many white apple leafhoppers flying around in some orchards. The
population can be reduced by spraying Thiodan, Provado, or Sevin. If there
aren't very many, you can wait until August and see if the second generation
needs to be controlled.
- I don't see any additional rose leafhoppers yet. Perhaps there won't
be as many this year as other years. We'll see.
- Green apple aphids have had a big week. I see plenty of green apple
aphids especially in trees that were pruned heavily. If you have lots
of aphids, my advise to you is 'wait a week'. Often in a week most of
the aphids can be consumed by predators.
6/21/04 - Really
there is nothing new to report. Continue to check for European red mites
and two-spotted spider mites. I have not found any two spotted mite problems
this season. I have found several orchards that required a miticide application
to control red mites.
- I have not found any potato leafhoppers yet this season. Be sure to
check your young trees for leafhoppers. Check the newest few leaves on
terminal shoots. This is usually where the leafhoppers appear. They are
not a problem on mature trees, but they do stunt the growth of young trees.
- Rose leafhoppers continue to migrate onto apple trees, but are not a
problem at this time. If a insecticide application is necessary, it should
be applied in mid July.
- I see more green apple aphids, but also more aphid predators. I don't
think green apple aphids will require spraying in any orchard.
- Starting in the end of June or early July there are more spores of both
sooty blotch and fly speck around. Before late June these summer diseases
are not much of a threat. After late June you need to keep your trees
protected from summer diseases. This can be accomplished by applying half
rates of Captan every two weeks or half rates of Captan plus Topsin M
every 3 weeks.
I didn't get to finish writing my observations from yesterday:
For those of you whose trees have San Jose Scale, Orchard Radar predicts
San Jose Scale crawlers should start emerging June 17 in Greenville, June
19 in North Kingstown, and June 21 in Newport County. If you need to control
San Jose Scale, an insecticide should be applied when crawlers first emerge
and then again 7-10 days later. Esteem works very well to control crawlers.
Imidan or Guthion will also control the crawlers, but probably not as
well as the Esteem.
- Green apple aphids are present in most orchards and so are aphid predators.
In nearly all situations, the natural aphid predators will control green
apple aphid, so an insecticide treatment is not needed.
It's a nice time of year in the orchard - you can usually spread out the
time between spray applications. Insecticides are generally not needed
for several weeks, now that plum curculio season is finished. As long
as apple scab is under control you can go 2-3 weeks between sprays. Spray
Captan every 2 weeks or go 3 weeks if you spray Captan and Topsin M.
- There are a few pests to watch for. European red mites and two spotted
spider mites are always a concern and need to be monitored. From now through
mid-July, the spray threshold for red mites is 2.5 mites per leaf or 54%
of leaves with mites. If your trees reach this threshold apply a miticide.
Use Nexter (new formulation of Pyramite) or try Zeal (a new miticide).
In the past, we've had good results controlling mites by mixing Vendex
with Tactic (a spreader-sticker). Vendex plus Tactic is probably less
expensive than other miticides.
- Another possible pest now is rose leafhopper. I just started seeing
rose leafhopper on apple trees today. These leafhoppers spend the first
part of the season on rose and then migrate to apples this time of year.
Nothing should be done about rose leafhoppers now. If they do become a
problem, you can spray the nymphs later in July.
- Some orchards may still have some white apple leafhopper. These are
present now as large nymphs or adults (the adults are the ones flying
around). If you do have many white apple leafhoppers now and you see the
white stippling damage caused by leafhopper feeding, you can apply Provado,
Thiodan or Sevin to control them. The threshold is 25 nymphs per 100 leaves.
- This hot weather is bringing out the last of the plum curculio. Orchards
that were sprayed with insecticides in the last 10 days should be protected
through this hot weather. If you find new scars, consider applying a border
spray of insecticide.
- This hot weather is not expected to last, but I'm sure it's speeding
up European red mite egg hatch. At this time of year, probably any miticide
will work quite well: Apollo, Savey, Pyramite (now called Nexter). The
threshold until the middle of June is 1 mite per leaf or 30% of leaves
with mites. From June 15 to July 15 the threshold is 2.5 mites per leaf
or 54% of leaves with red mites.
I found some fruit scab today, first I've seen this season.
- I have found caterpillar feeding damage in a few orchards. The caterpillars
are taking big bites, similar to green fruit worm injury. I believe insect
is the winter moth, Operophtera brumata, which I believe is a new insect
for Rhode Island. It is originally from Europe and has been in Canada
for many years. This spring it has been reported in coastal Massachusetts
orchards. Insecticides applied against plum curculio should control the
green winter moth caterpillars. I'll work on getting a picture on this
- And yesterday I said it was too late to spray for first generation leafminer,
and then I was in an orchard today where all the mines were sap feeding
mines. The grower only has a day or two if he wants to treat these trees
with Provado or AgriMek, but it wasn't too late now. Once more than 10%
of mines have advanced to the tissue feeding stage (when they are visible
from the upper leaf surface) it is too late to control the mines.
- I wrote a lot yesterday - Read that!
I'm finding more apple scab in orchards that I thought were free from
scab. Be sure to check leaves closely. New lesions can be quite faint
and difficult to see. A full rate of Captan should be applied to trees
with more than just a tiny bit of scab.
- I'm surprised how active plum curculio have been during this cool weather.
I've seen many fresh egg laying scars, especially in orchards not well
protected with insecticides. Orchard Radar predicts the final plum curculio
spray is needed June 1 or later in the Greenville area; June 5 or later
in North Kingstown as well as Newport and Little Compton. Plum curculio
migration is expected to continue for another 2 weeks after that, but
provided we don't get more than 2 inches of rain, the insecticide should
control through the end of plum curculio migration.
- If plum curculios aren't killed (let's say you only apply one insecticide
at petal fall) they can continue to feed and lay eggs well into July.
And when larger fruit are attacked by plum curculio, the tend to stay
on the trees into harvest. Small fruit attacked by plum curculio tend
to fall off.
- It is probably too late to control first generation leafminer mines
now. If you see that you have too many mines on your leaves (more than
13 mines out of 100 fruit cluster leaves), you can wait and try to control
the second generation mines. It is more difficult to control the second
generation and probably would require two applications of Provado, about
7 days apart. If sprays are needed for second generation leafminer control
the first application of Provado would be applied around mid July. The
threshold for second generation mines is 1 mine per leaf. If you exceeded
the threshold for first generation, you can expect you'll exceed the threshold
for the second generation.
- I've seen very few white apple leafhoppers this spring, even on trees
not treated with Sevin for thinning.
-Green apple aphids are starting to appear on new shoots. In nearly every
case, natural predators control aphids beautifully - No insecticide needed!
- Once you have applied your final plum curculio spray, it's a good time
to relax on spraying. Hopefully you won't need another insecticide application
until it's time to spray for apple maggot fly. Usually an insecticide
isn't needed for apple maggot fly until the first or second week of July.
So, along with your final plum curculio spray, include Topsin M with the
Captan so you can go three weeks before spraying again.
According to Orchard Radar, we can expect to start seeing San Jose Scale
crawlers on July 18.
Cool weather has slowed down plum curculio migration. Orchard Radar now
predict that the last insecticide against plum curculio can be applied
no earlier than June 2 in the Greenville area. In North Kingstown, the
predicted date for final plum curculio spray is June 3, and the Newport
area date is June 5. If your insecticide is applied at these dates or
later, your fruit should be protected through the end of plum curculio
migration. If you have questions about this, please call me at 874-2750.
We are past primary apple scab season in all but the latest orchards in
the state. If your trees are past petal fall, primary scab season is most
likely over in your orchard. Continue to monitor your leaves and fruit
for lesions. Apply full rates of Captan if you find even a little bit
of scab. Secondary scab spreads very easily. It does not take very many
hours of leaf wetness to cause an infection for secondary scab.
- I've seen a lot of plum curculio damage over the last few days. In areas
where the temperature exceeded 70 degrees and was humid, the plum curculio
have been very active. We are nearing the end of plum curculio migration
season, but we are not there yet. At this point, Orchard Radar predicts
that a final plum curculio spray needs to be applied on May 29 or later
in Greenville, May 31 or later in North Kingstown, June 3 or later in
Newport County. This prediction is based on when plum curculio are expected
to finish migrating (based on degree day models) and how long full rates
of Imidan are expected to protect the fruit. So, insecticide applications
are still needed against plum curculio.
- I have seen numerous winding trails caused by European apple sawflies.
I find them in orchards that did not receive an insecticide right at petal
fall - some growers waited up to a week after petal fall. Spraying insecticdes
over the next week will kill the sawfly larvae after they leave one fruit
and before they enter another fruit. In unsprayed trees, European apple
sawfly can attack nearly every fruit. They are rarely a problem in sprayed
- I found one leafminer that had advanced to the tissue feeding stage.
This is when the mine is visible from the upper leaf surface. If you are
planning to spray to control leafminer mines, now is the time to do it.
Use Provado, AgriMek or Calypso.
- Some growers have applied miticides to control European red mites. In
each situation the mites have been well controlled with Apollo or Pyramite.
Through the middle of June the threshold for European red mite is 30%
of leaves with mites.
This warm, humid weather is perfect for plum curculio egg laying. All
fruit trees should be protected now against plum curculio. Use Imidan,
Guthion, or Avaunt at full rates.
- The rain of May 18 probably released the last of the overwintering ascospores
for the season in the Greenville area. Orchards along the coast are further
behind, and still in primary apple scab season. After spraying this week,
you can probably switch to spraying a fungicide every 2 weeks, assuming
you've had good fungicide coverage throughout the season. Be sure to scout
your trees now for lesions and spray with full rates of Captan if you
find more than just a very few lesions. I know this is sounds very subjective
- but it is - and it's better to be cautious when dealing with scab. In
addition to the Captan, you can add Sovran, Flint, Rubigan, or Nova.
-Leafminer sap feeding mines are just becoming visible on the underside
of leaves. Now is the time to treat if you need to control leafminer.
Use Provado, Calypso, or AgriMek.
5/17/04 - We
are nearly at the end of primary scab season. Apply a fungicide this week
and then you can probably switch to spraying a fungicide every two weeks.
If you do have scab in your orchard now, apply full rates of Captan 5-7
days apart. You can also add Rubigan, Nova, Sovran or Flint to the Captan
to help burn out scab lesions.
found plum curculio egg laying scars in three orchards today. It is time
to have your trees protected with Imidan, Guthion or Avaunt.
-Leafminer. Leafminer adults are still active in orchards laying eggs.
Eggs laid earlier in the season have started hatching. If you intend to
spray against sap feeding mines, plan on spraying AgriMek at petal fall
or Provado or Calypso about 10 days after petal fall, at first cover.
(AgriMek must be applied with a penetrant to get the insecticide into
the leaves. Use oil or LI 700.) We had a lot of good weather this spring,
allowing leafminers to lay many eggs. This could be a big year for leafminers!
I'm finding many orchards with European red mite populations above the
threshold of 30% of leaves with mites. If you are in this situation, consider
applying Apollo, Savey, Danitol or AgriMek. AgriMek would be a good choice
if you also needed to control leafminers.
- Everyone's set looks very heavy! Thin aggressively! Check out Orchard
Radar for help on thinning. There are links to the three Rhode Island
Orchar Radar sites on the front page of this Apple
I'm finding apple scab lesions in more orchards. The lesions I found yesterday
were much easier to see than they were on May 10. The heat has made them
darker and more visible. To look for lesions, stand under a McIntosh tree
or a tree where it is difficult to spray. Look up into the canopy to search
for lesions. If you find any lesions, consider applying a full rate of
Captan now and again in 5-7 days. You can add Rubigan, Nova, Sovran or
Flint to the Captan, but realize that this approach strongly encourages
scab resistance to these chemicals.
- I am finding European red mites in more orchards. I think many growers
could not make adequate oil applications this spring. It is much better
to control mites earlier than later. Consider applying a miticide soon
if 30% of leaves have mites. Use Apollo, Savey, Danitol, or AgriMek. Danitol
and AgriMek will also control leafminers, but Danitol is a synthetic pyrethroid
and we discourage growers from using synthetic pyrethroids. If you used
a miticide last year, use a different one this year. And remember, Apollo
and Savey are very similar chemicals, so if you used either one last year,
don't use either one this year.
- Petal fall has occurred in many orchards. Include Imidan in your petal
fall spray to control plum curculio and European apple sawfly. Sawflies
have been busy laying eggs during bloom. I don't have many traps set up,
but I caught sawflies in every orchard where
I do have traps.
- I am recording telephone messages each week, usually on Mondays. The
number is 949-1456.
We had another apple scab infection period on Mother's Day, May 9th. This
was a very important infection period because many spores matured during
the week and weren't released until the rain of May 9th. IF you had sprayed
a fungicide since Wednesday, May 5th, your trees should have been well
protected. If your last fungicide application was applied before May 5th,
consider applying a fungicide with kickback such as Rubigan, Nova, Sovran,
- I did find my first apple scab lesions fo the season today. I did not
find them on the oldest leaves, but instead on the middle aged leaves.
The lesions were very small and just looked like gray smudges. Look now
for lesions in your trees. If you find them, apply a full rate of Captan
now and again in 5-7 days. The predicted hot weather should help burn
out scab lesions.
- Check your trees now for European red mites. Check the underside of
oldest leaves for the small, red mites. If 30% of leaves have red mites,
consider applying a miticide at petal fall. I have seen quite a few mites
in some orchards.
-TWILIGHT MEETING Wednesday! Click here for
- That was a huge infection period on Sunday
May 2 through Tuesday morning May 4th. Hopefully most of your trees were
protected with a fungicide before the wet weather. If not, apply full
rates of Rubigan, Nova, Sovran or Flint as soon as possible.
- I found my first hatched European red mite today. I found it at URI's
East Farm where the trees are barely in pink now. I expect ERM started
hatching in the Greenville area several days ago. It is too late to apply
dormant oil to control red mites, unless some areas are still at tight
cluster. (Perhaps Newport and Little Compton are still in tight cluster.)
-More tarnished plant bugs were caught over
this past week, but no location is above the spray threshold.
4/30/04 - McIntosh trees
will probably be at pink on May 1. This warm weather has really moved
the trees forward - and apple scab as well. The next wetting period will
release a HUGH number of ascospores, making the next period of wet weather
extremely important. Either spray before the next forcasted rain (5/2
afternoon) or come in immediately afterwards with a kickback fungicide
(Rubigan, Nova, Sovran, or Flint).
- At this point, reduce oil rates to 1 gallon oil per 100 gallons of water.
4/29/04 - We did have a major apple scab infection period from Sunday
night, 4/25 through Tuesday morning 4/27. Approximately 20% of overwintering
spores should have been matured as discharged as of 4/27. We are now entering
the accelerated phase of apple scab. Now is the time to really concentrate
your efforts to protect your trees from scab. If you are not protected
from scab with a contact fungicide before an infection period, be sure
to use Rubigan, Nova, Flint, or Sovran soon after an infection period.
- Continue to add oil to your sprays. Reduce the amount of oil to 1-2
gallons of oil per 100 gallons of water. Don't apply oil if a frost is
expected within 48 hours of application.
- Last week there was a major early season apple scab
infection period. Today's wet weather may or may not be an infection
period. All growers should have applied a fungicide by now! If not, you
could run into serious problems with scab.
- I understand there are problems buying Syllit this year. Growers should
depend on other protectant fungicides such as Manzate or Polyram. Manzate
or Polyram can be used at the full rate through bloom. If you choose to
use only a half rate you can extend your use until 77 days before harvest
(around 2nd cover).
- Leafminers are above threshold in about half
of blocks monitored with red sticky spheres. This is usually how it is
every year. Blocks with large, old trees are most susceptible to high
leafminer populations. Leafminer can be controlled at pink with a synthetic
pyrethroid, but it is recommended you wait until after bloom and use Agrimek,
Provado, or Calypso. Calypso has the added advantage of also controlling
-I am catching tarnished plant bugs on white sticky
traps, but not in high numbers. No orchard is near the threshold.
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