SW MICHIGAN APPLE MATURITY REPORT

ISSUE 4 – Sept 26, 2007

Summaries of apple maturity for SW Michigan began in early September and will continue through mid October, depending on the season. The focus in this report is for controlled atmosphere storage of fruit. Fruit harvested for more immediate consumption can be picked riper for better color, size, and flavor. See accompanying graphs to see the trends.

The samples for these reports are collected in Berrien County—the maturity is only a broad indication of trends for this area. Contact Bill Shane at SWMREC 269-944-1477 x 205 if you would like to have samples from your farm tested for maturity.

Jonathan no more sampling, most harvested in area.

Empire no more sampling, most harvested in areas
Honeycrisp -- most are harvested.

Jonagold – most are harvested

Golden Delicious (8 samples, 4th week). Firmness this week averages 17.2 compared to 17.5 for last week. The starch index for this week averaged 4.1 quite a jump from 2.6 for last week. Brix averaged 14.3, last week was 14.0. Harvest on this variety going full steam. Most blocks testing mature according to starch conversion, pressure spread between excellent to acceptable for long term CA. Some beautiful looking Golden Delicious in local orchards.

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

Red Delicious (7 samples, 3^rd week). Firmness averaged 16.6 compared to 16.9 for last week. Starch conversion index is 3.7 about the same as last. Brix is averaging 11.1 compared to last weeks 10.3. All samples tested are below 17 lb, the threshold for acceptable for long term CA. Growers are rapidly harvesting this variety now.

CA longterm firmness Firmness ---- Starch removal -----------

Guidelines: Excellent Acceptable mid term immature mature overmature

Red Delicious > 18 lb 18 to 17 lb 17 to 16 lb < 2.5 2.5 to 5.0 > 5.0

IdaRed (4 samples, 2nd week). Firmness averaged 15.4 compared to last weeks 16.8. Starch conversion index is 3.4 compared to 2.8 for last week, with brix of 12 compared to 11.4 for last week. Fruit is softening rapidly—fruit that will be stored for longer term should be picked quickly. This variety is disappearing rapidly in area orchards.

CA longterm firmness Firmness ---- Starch removal -----------

Guidelines: Excellent Acceptable mid term immature mature overmature

IdaRed > 16 lb 15 to 16 lb 14 to 15 lb < 3.5 3.5 to 6.0 > 6.0

Fuji (5 samples, 1^st week). Looking at the standard Fujis (early type Fujis were not included in these samples) fruit firmness averaged 19.3 lb, starch conversion was 3.6, and brix was 14.1. These are testing very similar to this same time in 2006. Excellent firmness will allow delay of harvest in most orchards to wait for starch conversion, better size, and better skin color.

Braeburn (2 samples, 1^st week). Firmness averaged 21.9 lb, starch conversion 3.1, and brix of 11.2. Excellent firmness will allow delay of harvest to wait for better size and better skin color.

Current and past years summaries can be found on the SW Michigan Research and Extension Center web site: www.maes.msu.edu/swmrec. At this site click on publications and then fruit reports. Reports for all the apple producing regions of Michigan can be found by going to the following web site: web1.msue.msu.edu/fruit/ripeapple.htm.

This report and project is made possible by the support of our sponsors which include Gerber Products Company, Valent USA, Michigan Apple Research Committee, Michigan State Horticultural Society, Michigan Agricultural Experiment Station, and Michigan State University Extension. SW growers providing apples include Grandview Orchards, Mammoth Farms, Oak Hill, Bixby Orchards, Willmeng Farms, and Czuba Farms.