Full Bloom finally occurred on May 3, 2008. The warm weekend finally brought the flowers out. Full bloom had already happened on the other apple cultivars in lower elevation North Central Washington. This date was moved forward one day after further observations of the flower development. There was no daily monitoring over the May 3rd-4th weekend. East Oroville reported full bloom on May 4th.
The Red Delicious blossom date was 7 days later than 2007 development date, which was about average.
The Red Delicious tree that serves as the "standard" for the WSU TFREC site was at "Full Bloom " on April 26, 2007.
THE WSU-TFREC SITE IS SOMEWHAT COOLER THAN MANY LOW ELEVATION SITES, BUT WARMER THAN ALL BUT THE WARMEST SITES TO THE NORTH OF WENATCHEE. RED DELICIOUS BLOOMS A FEW DAYS LATER THAN SOME COMMON APPLE CULTIVARS.
The current model is based on the total of daily high temperature degrees above 43 F. It is highly inaccurate some years unless the season numbers are reset to 440 at the time green tip stage occurs on 40% of the blossom buds on the North side of the tree. If we use green tip as a "biofix," accuracy after that stage is improved, but may still vary by a few days. We hope to develop a more accurate apple blossom model, but the one used for this page is as good as we have at this time. See theTable at the lower end of this page for historic data on date of green tip stage relative to actual degree days, and what the degree days would have been at full bloom if we had not reset to 440.
There is a significant variation in actual blossom stage across any region due to slope direction, elevation, and variety (cultivar). Use the information below to forecast the time of specific blossom stages, but as a rough guideline only.
Red Delicious Blossom Stages by Date in 2008 at cool, flat low elevation Wenatchee site,(starts with green tip stage biofix, which was March 24:
Stage: |
Gr. Tip
440
|
1/2" Green
510 |
Tight Clstr
630 |
1st Pink
780 |
Full Pink
860 |
1st Blm
930 |
Full Bloom
1040 |
P fall
|
TFREC 2008 |
3/24 |
4/1 |
4/11 |
4/22 |
4/26 |
4/30 |
5/3 |
5/10 |
TFREC 2007 |
3/23 |
3/30 |
4/6 |
4/14 |
4/18 |
4/22 |
4/26 |
5/3 |
| . |
| TFREC Normal |
3/27 |
4/1 |
4/6 |
4/13 |
4/18 |
4/22 |
4/26 |
5/3 |
Blossom Degree Days by Date: Red indicates actual or estimated full bloom dates for red delicious.
| DATE |
WSU -
TFREC |
North
Cashmere |
East Wenatchee Airport |
Brays
Landing |
Pogue
Flats |
East
Oroville |
| 4/30/2008 |
| 5/1/2008 |
| 5/2/2008 |
| 5/3/2008 |
| 5/4/2008 |
| 5/5/2008 |
| 5/6/2008 |
| 5/7/2008 |
| 5/8/2008 |
| 5/9/2008 |
| 5/10/2008 |
| 5/11/2008 |
| 5/12/2008 |
| 5/13/2008 |
| 5/14/2008 |
|
| 935 |
| 954 |
| 977 |
| 1000 |
| 1032 |
| 1064 |
| 1094 |
| 1117 |
| 1140 |
| 1165 |
| 1192 |
| 1212 |
| 1234 |
| 1259 |
| 1287 |
|
| 862 |
| 881 |
| 902 |
| 927 |
| 960 |
| 992 |
| 1022 |
| 1045 |
| 1068 |
| 1093 |
| 1120 |
| 1140 |
| 1162 |
| 1187 |
| 1215 |
|
| 835 |
| 852 |
| 872 |
| 894 |
| 923 |
| 952 |
| 982 |
| 1010 |
| 1032 |
| 1053 |
| 1076 |
| 1101 |
| 1121 |
| 1142 |
| 1166 |
|
| 832 |
| 850 |
| 872 |
| 895 |
| 926 |
| 955 |
| 985 |
| 1013 |
| 1035 |
| 1056 |
| 1079 |
| 1104 |
| 1124 |
| 1145 |
| 1169 |
|
| 789 |
| 806 |
| 827 |
| 853 |
| 883 |
| 912 |
| 942 |
| 970 |
| 992 |
| 1013 |
| 1036 |
| 1061 |
| 1081 |
| 1102 |
| 1126 |
|
| 874 |
| 893 |
| 917 |
| 941 |
| 974 |
| 1006 |
| 1036 |
| 1059 |
| 1082 |
| 1107 |
| 1134 |
| 1154 |
| 1176 |
| 1201 |
| 1229 |
|
 |
 |
 |
1/2 inch green (510 DD)
04/06/2008
|
Tight cluster stage 630DD.
|
|
 |
 |
 |
TC - First Pink Showing 700 DD
|
Late Tight Cluster - 795 DD
|
Late Full Pink - 900 DD
|
|
