Northern Michigan FRUITNET'99
Weekly Update
James E. Nugent      Gary E. Thornton       William M. Klein
NW Michigan Horticultural Research Station
Michigan State University

August 26, 1999

WEATHER

Rainfall total for August is 1.48", to date. It was dry last week, and only 0.22" has fallen since Monday at the NWMHRS. Evaporation last week totaled 1.27".

GROWING DEGREE DAYS
 
As of 8/26
1999
1998
1997
DD42
3099
3207
2539
DD50
2044
2115
1620

INSECTS & DISEASE

In apples, apple maggot adults continue to emerge, although numbers declined this past week in the abandoned apple block. Growers who are not trapping should keep their apples protected. Codling moths continue to emerge, averaging 3 to 4 per trap. Depending on trap catches, growers may need a second spray for this generation. European red mites continue to be a threat to fresh market apples in particular. In general populations are down, but where they are up, high numbers can lay eggs in the calyx end of the fruit. White apple leafhoppers are not above threshold, but they can be a nuisance to pickers. Spotted tentiform leaf miners continue to emerge in very high numbers. Trap catches were up from last week. In blocks with 3 or more mines per leaf it still may be worthwhile to control them where fruit size is a critical issue.

Two spotted spider mites and European red mites continue to build in tart cherries, but it would not pay to control them at this time. Cherry leaf spot is showing up in many orchards. These infections probably occurred prior to most post harvest spray applications (heavy infection July 21st.) It would be of little value to try to control leaf spot any more this season. 

As plums near harvest, growers should keep fruit protected against brown rot. Leaf spot has again shown up in Damson plums. Growers should check theirs, and if present, an application of an appropriate fungicide would be wise to prevent early defoliation. Early defoliation in plums can lead to severe winter injury. 

MISCELLANEOUS

REMINDER: The NW Michigan Horticultural Research Station Open House and Equipment Show will be held on Thursday, Sept. 2nd. The equipment display area will open at 1:00 p.m. There will be a program from 2:15 until 3:00 p.m. "Celebrating 20 Years of Service" to commemorate the 20th anniversary of the Research Station. Sprayer demonstrations will begin at 3:45 p.m. A social time, beginning at 5:30 will be followed at 6:30 by a pig roast, sponsored by the Leelanau County Horticultural Society. Tickets for the pig roast will be available at the door for $15. The evening will conclude with a short program conducted by the Leelanau Horticultural Society. Everyone is invited to attend!

NW Michigan Horticultural Research Station
Insect Trap Count Averages - 1999
 
DATE Codling Moth Spotted Tentiform Leaf Miner Lesser Peach Tree Borer American Plum Borer Oblique Banded Leafroller Grape Berry Moth Greater Peach Tree Borer
5/18 0 660 8 30      
5/24 0 88 1.3 14.3 0    
6/1 .6 85 17 4.6 0 9  
6/8 2 15 17.3 2.7 0 7.7  
6/14 1 342 11 .3 7 4.3 6
6/21 .33 511 10 0 2.3 1 5
6/28 .75 455 6.3 .75 2.3 16.3 1.6
7/5 0 327 7.3 2.6 0.3 2.3 1.6
7/12 0.3 274 6.6 3.6 7.6 .3 3.6
7/26 0.3 233 4.6 11 1 5 4
8/2 2.3 570 7.3 4.3 1.6 35 4.6
8/9 4.3 396 1.3 3.3 0.6 15 3.3
8/16 .67 640 3 4.3 2 9.3 5
8/23 .67 631 1.7 1 2 6.7 .7

NW Michigan Horticultural Research Station
Growing Degree Day Accumulations for July 26 - Aug. 26, 1999


GDD
Total Base
GDD
Total Base
Date
Max
Min
50
50
42
42
7/26/99
83
66
24.50
1497.45
32.50
2311.04
7/27/99
79
65
22.00
1519.45
30.00
2341.04
7/28/99
84
65
24.50
1543.95
32.50
2373.54
7/29/99
87
65
26.00
1569.95
34.00
2407.54
7/30/99
93
65
29.00
1598.95
37.00
2444.54
7/31/99
80
67
23.50
1622.45
31.50
2476.04
8/1/99
74
63
18.50
1640.95
26.50
2502.54
8/2/99
73
59
16.00
1656.95
24.00
2526.54
8/3/99
72
61
16.50
1673.45
24.50
2551.04
8/4/99
75
62
18.50
1691.95
26.50
2577.54
8/5/99
71
57
14.00
1705.95
22.00
2599.54
8/6/99
70
59
14.50
1720.45
22.50
2622.04
8/7/99
78
57
17.50
1737.95
25.50
2647.54
8/8/99
67
57
12.00
1749.95
20.00
2667.54
8/9/99
69
51
10.00
1759.95
18.00
2685.54
8/10/99
72
53
12.50
1772.45
20.50
2706.04
8/11/99
77
60
18.50
1790.95
26.50
2732.54
8/12/99
82
63
22.50
1813.45
30.50
2763.04
8/13/99
72
66
19.00
1832.45
27.00
2790.04
8/14/99
71
58
14.50
1846.95
22.50
2812.54
8/15/99
76
56
16.00
1862.95
24.00
2836.54
8/16/99
81
56
18.50
1881.45
26.50
2863.04
8/17/99
73
64
18.50
1899.95
26.50
2889.54
8/18/99
70
61
15.50
1915.45
23.50
2913.04
8/19/99
74
59
16.50
1931.95
24.50
2937.54
8/20/99
74
55
14.50
1946.45
22.50
2960.04
8/21/99
77
54
15.50
1961.95
23.50
2983.54
8/22/99
80
59
19.50
1981.45
27.50
3011.04
8/23/99
73
64
18.50
1999.95
26.50
3037.54
8/24/99
83
63
23.00
2022.95
31.00
3068.54
8/25/99
63
0.00
2022.95
0.00
3068.54
8/26/99
0.00
2022.95
0.00
3068.54

ACTUAL AND PREDICTED DEGREE-DAY
ACCUMULATIONS SINCE MARCH 1 1999 (*)

Please send any comments or suggestions regarding this site to: 
Bill Klein, kleinw@pilot.msu.edu

Last Revised:8-30-99