ISSUE 1 – Sept 5, 2007
Summaries of apple maturity for
Current and past years summaries
can be found on the SW Michigan Research and
Jonathan (7 sites sampled) Fruit firmness is generally in the excellent
zone of 28.0 to 13.5 lbs with starch removal average of 3.3 (range 7 to
3). 16.5 to 20 lb with starch removal in
the mature zone for about half the blocks tested. Brix is averaging 13. Background color of Jonathan ranges from
quite green to approaching light green/slight cream. Some harvesting of Jonathans for processing
is occurring in the area. Excellent
firmness will allow growers to delay harvest to wait for better size and better
starch conversion. Jonathan looks like
it is maturing slightly ahead of last year.
CA longterm firmness Firmness ---- Starch removal -----------
Guidelines: Excellent Acceptable short term immature mature overmature
Jonathan > 16 lb 16 to 15 lb < 15 < 3.5 3.5 to 5.5 > 5.5
Empire (5 samples) firmness averaged 18.1 (range 23 to 14 lb. Starch removal averaged (2.5 (range 1 to 4). Brix average 11.5 degrees. Blush of Empires have been improving and is very good in blocks with lower vigor and good fruit exposure. Many Empires have already been harvested over the last two weeks for taffy apples and a few are being picked now for apple slices. Based on these tests, harvest can be delayed for Empire apples destined for CA storage or for local sales.
CA longterm firmness Firmness ---- Starch removal -----------
Guidelines: Excellent Acceptable short term immature mature overmature
Empire (export) > 18 lb 18 to 17 lb < 15 < 3.5 3.5 to 5.5 > 5.5
(domestic) > 16 lb 16 to 15 lb < 15 < 3.5 3.5 to 5.5 > 5.5
Honeycrisp (no official test samples) are being harvested this week and next week. Quite a bit of variability is seen with this variety from site to site and even tree to tree. Color is fair to excellent, better color on sandier sites with exposed fruit. Skin cracking is common on these sandier sites. Remember that Honeycrisp stores best in the 38 F range—the higher temperature helps to prevent fruit disorders.
Jonagold (3 sample sites) are testing very firm in the 16 to 24 lb range, average 19.0 lb. Starch removal index readings range from 2 to 7 with an average of 2.3. Average brix is 13.2. Good firmness will allow delay of harvest to wait for better background color if needed.
CA longterm firmness Firmness ---- Starch removal -----------
Guidelines: Excellent Acceptable short term immature mature overmature
Jonagold > 16 lb 16 to 15 lb < 15 < 3.5 3.5 to 5.5 > 5.5
Golden Delicious (6 samples). This is the first look at this variety for this season. Firmness is ranging from 25 down to 16 lb with an average of 18.8 lb and starch index is ranging from 1 to 6, averaging 1.3. Brix averaged 12.9. Fruit finish is very nice this year in general aside from some sites with frost marks.
CA longterm firmness Firmness ---- Starch removal -----------
Guidelines: Excellent Acceptable short term immature mature overmature
G. Delicious > 17 lb 17 to 16 lb < 15 < 3.0 3.0 to 5.0 > 5.0
This report and project is made
possible by the support of our sponsors which include Gerber Products Company, Valent