WEATHER

Conditions are again getting dry. Precipitation at the NWMHRS in August totaled 1.48", with none in September. Most of the August rain occurred in the first two weeks. Evaporation in August averaged 1.19" per week, with evaporation the first week of September up to 1.54" per week.

GROWING DEGREE DAY ACCUMULATIONS
Degree days base 42 are one day behind last year but did not reach this level in 1997 until October 17^th.
 

Year	1999	1998	1997
DD42	3445	3478	2760
DD50	2295	2306	1766

INSECTS AND DISEASES

Apples: McIntosh harvest is just beginning. Codling moth trap catches are down from last week, at less than one moth per trap at the abandoned apple orchard. At the NWMHRS, the trap catches were zero. It looks like the season for codling moth should be just about finished. Apple maggot emergence was down dramatically this past week. Growers still run the risk of having apple maggot show up in commercial blocks and should continue monitoring for another week. The dry weather has allowed the spray residue from any applications within the past 2 weeks to remain active, and that residue should provide adequate control for the remainder of the season. Spotted tentiform leaf miner trap catches remained high, averaging 564 per trap at the NWMHRS this past week. Additional mines will likely continue to show up, although further control efforts are not recommended.

Cherries: Cherry leaf spot defoliation varies by block, from completely defoliated to the total absence of leaf spot. Post harvest Bravo applications were extremely important this year!

Grapes: Bunch rot is appearing in some locations. Downy mildew is being observed on shoot tips in some susceptible varieties.

MISCELLANEOUS

Mouse guards should be removed if tight on the trunk. These areas are very susceptible to late fall/early winter cold injury. That portion of the trunk is just not as winter hardy as the rest. If the mouse guards are still needed, they can be reapplied in late October or early November. This is particularly important for sweet cherries, peaches, apricots and plums.

Fall irrigation can be useful to size fruit in late maturing apples if the soil moisture gets low. Irrigation rates needed are considerably lower on a daily basis than during summer, due to the lower evapo-transpiration rates that result from cooler fall temperatures. However, just because the rate needed per day is lower does not mean it is any less important.

Fall is an important time for strawberries to have adequate moisture. Flower buds are being set throughout the fall that will determine next year's potential yield. Dry conditions during fall can significantly reduce flower bud formation, hurting next year's yield. As mentioned with apples, the strawberry plants don't use much water during cool fall days, but growers should still check the fields regularly to be sure the plants are getting adequate moisture.

Apple maturity: To get information on apple maturity in NW Michigan, subscribe to our e-mail or fax version of the apple maturity report by contacting the NWMHRS at 946-1510. You can also access the report via Code-a-Phone at 946-3063.
 

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
8/30	1	612	3.7	1.3	4	1.3	0.3
9/7	0	564	2.3	2	5	3.3	0.3

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

Last Revised:9-7-99