Rhode Island Apple IPM
July 29, 2010: Recorded Apple Pest Message in Print

July 29, 2010
Hi Fruit Growers,
I did make it to a few orchards today. I found some apples with sooty blotch
and fly speck where not much fungicide has been applied this year. Continue
with your fungicide applications as late as you can. Any fruit that is
harvested more than 30 days after the last fungicide application may get sooty
mold and fly speck – so the later you can spray the better. Be sure to mind
the “days to harvest” interval for all pesticide labels.

I hear apple maggot flies are still be captured on traps in Massachusetts and
New York. Also, I found some apple maggot stings in fruit that received
insufficient insecticide applications. If you suspect apple maggot damage, cut
fruit in half and look for the brown trails. The URI Cooperative Extension
Factsheet has pretty good pictures, though it’s generally harder to see the
apple maggot sting from the outside of the apple than is shown in the
factsheet. Here’s the link:
http://www.uri.edu/ce/factsheets/sheets/applemaggot.html

I’m offering to collect leaf tissue analysis samples to some growers. I’m not
sure how many I’ll be able to do so I’m offering this on a first come, first
serve basis. You guys really should be doing this on your own, but it’s my own
fault that I’ve spoiled you! I’ll send the leaf and soil sample to the
University of Maine and the charge will probably be about $28 per sample. This
is for commercial growers only. If you’d like me to take samples, email me or
call me at 874-2967.

What follows is from Jon Clements on this week’s UMass Healthy Fruit
newsletter about using ReTain to retard ripening:

The 'early' apple harvest and timing of ReTain application seems to be the
topic of choice right now. Clearly, Mac harvest is going to be about a week
ahead of average, but don't take that as gospel. A cool August could really
move it along or a hot August could retard it some. (Mostly due to lack of
color development.) Frankly, I have no real indication how early 'early'
apples are right now, largely because we don't have particularly good harvest
date records on them and they have a tendency to be variable. (Plus I have
been travelling a lot!) But I expect they are at least 10 days early. Peach
maturity right now looks to be about a week to two weeks (depending who you
talk to) ahead of 'average' but I am not sure how much that means.

I would suggest you think about applying ReTain about a week earlier than you
might most years. To me, that means the first or second week in August for the
brunt of growers who will be well into McIntosh harvest by Labor Day and want
to delay some blocks. That is 21-28 days before anticipated harvest. U-pick
growers might be looking at the 3rd week of August as a better timing window,
because they are looking to hold fruit on the trees a little longer into the
growing season than (for example) the wholesale grower with a lot of fruit
going into storage. But again, use your gut feel regarding the weather, fruit
condition, fruit color, and early variety harvest as we go along. Every block
and variety have different destinations and purposes are -- ReTain application
should be tailored to the individual situation and desired result(s).

All that being said, here are some ReTain application reminders:
• Use one pouch ReTain (full rate) per acre with organosilicone surfactant
(0.05 to 0.1% or app. 6-12 oz. per 100 gallons) per ALL label directions
• Do not apply to stressed trees -- it will not work well
• Apply 2-4 weeks before anticipated harvest, however, the 2-3 week window
being best for most
• Apply in a water volume of 100 gallons per acre, and ideally in the morning
or evening under slower drying conditions; ReTain is rainfast in 8 hours
• ReTain has a 7 day pre-harvest interval
• ReTain can be used on Gala and Honeycrisp at half-rate to even-out ripening

Heather