MSU Fruit Team Apple Maturity Report 2005
Grand Rapids Area Report Number 4
September 21, 2005
This program is made possible by the support of our sponsors which include:
Gerber Products Michigan Apple Research Committee
Project GREEEN Michigan Apple Shippers
Valent USA Michigan State Horticulture Society
MSU Extension Michigan Agriculture Experiment Station
Our thanks to these sponsors.
Overview
Temperatures over the last week continue to be slightly above average, with very little rainfall. Rains are predicted for several days this coming weekend. Harvest is well underway for apples and growers will be picking just about every day they can until the end of harvest.
Gala
Harvest should be complete for Gala. Recent Gala samples show ethylene and starch
removal have increased to overmature levels. Firmness is still pretty good, but continues
to decrease. Only Retain treated fruit is still testing to be good for any type of storage
at this time.
McIntosh
Harvest of McIntosh is just about complete for
the season – some fruits are being left to gain some more color. Firmness is
declining and the starch removal index is showing fruits to be mature to overmature and
not recommended for more than mid to short-term storage at this time.
Honeycrisp
The majority of Honeycrisp harvest is done – a few fruits for U-pick and more
color are still hanging. Most maturity samples are showing Honeycrisp to be overmature
unless treated with Retain. Third pick fruits
on trees need more time.
Empire
Samples are quite firm – still averaging about 17 to 18 pounds of pressure.
Starch removal levels have increased over the past week to an average of 3. Red color is still averaging around 50% color.
Ethylene levels are still quite low, but starting to show a slight increase from last
week’s samples. Empires are ready for long-term storage at this time and will move
into a mid-term CA storage window by the middle of next week.
Jonathan
Firmness is still good at an average of 16 pounds pressure, but starting to decrease a
bit from last week’s sampling. Starch removal levels continue to increase, showing
most fruits to be mature. Brix levels are in the excellent range. Ethylene levels have
continued to increase. Red sports are being harvested now and are fit for long-term
storage. Other Jonathans should be harvested as well for long-term storage.
Jonagold
Continue to show movement towards mature, and even overmature levels on some fruits.
Starch removal levels are averaging about 4.5 from Monday’s samples, indicating that
Jonagolds are soon to be overmature and not fit for long storage. Firmness is holding
right around 16 pounds pressure and Brix levels are excellent. Because of the increasing
starch clearing, growers should not wait too long to harvest any remaining Jonagolds for
long term, even if color is only fair. Color
need to improve.
Cortland & Redcort
Red color is improving with about 70% red color showing now. Ethylene levels have
increased a bit from last week. Starch removal levels have remained about the same –
between 1 and 2, indicating that Cortland is not mature yet. Firmness is still excellent at about 16 pounds
pressure. Brix levels increased from last week and in the excellent category. Cortlands
and Red Corts are very close to bing ready for long-term storage at this time and could
move to the mid-term storage range by early next week.
This variety does seem to have a very wide maturity window.
Golden Delicious
Firmness is still very good, at 17 to 18 pound pressure on average. Ethylene levels
are low, but have shown a slight increase over the last week. Brix levels are in the
excellent range. Starch removal levels are holding at about 2 to 3 which is very close to
the mature level for Goldens. Golden Delicious are very close to being ready for long-term
storage at this time. A few have been harvested already. Watch early sites closely.
Red Delicious
We will start sampling Red Delicious for maturity levels. Southeastern Michigan is
reporting that Reds are starting to show some slight changes in maturity at this time. The
predicted harvest date for Reds in the Grand Rapids area is October 1st –
at this time it appears that we will be very close to that date or perhaps even slightly
ahead of it.
Ida Red, Rome, Spy, Mutsu
Immature, but we will start sampling soon.
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If you have an Email address, we would prefer to deliver this to you by Email. Please fax or send your email address to us at: schwalli@msu.edu, or Fax: 616-693-2317
This report will also be posted on the web at: http://web1.msue.msu.edu/fruit/ripeapple.htm
Here, you will also find apple harvest reports from other regions around the state.
Phil Schwallier, Amy Brown, Denise Ruwersma