Weather: During the past week, 0.72" rain fell. July rainfall at the NWMHRS totaled 8.83"! Average July rainfall at the NWMHRS for the past 18 years has been 2.54", with the prior greatest July rainfall being 4.76" in 1994. Evaporation the past week was 1.78". 
 

1999      1998       1997

DD42   2527     2509       2007
DD50   1657     1620       1275

Codling moth trap catches increased this week in an abandoned site, but still only averaged 2.3/trap. Growers should continue to monitor closely for adults. Last year, a late flight caught many growers by surprise and had fruit rejected.

Spotted tentiform leafminer injury appears to be heavier this year than in recent years. Trap catches are up and the second-generation flight should be peaking. The tissue feeding stage mines are showing up and additional mines will likely continue to show up over the next few weeks. Growers can still control for the remainder of this generation with Provado. Provado will only control the sap feeding stage, so don't expect the active larva in the tissue feeding stage to be controlled. The threshold at this time is 3 mines/leaf. If you already have 2-3 mines per leaf, by the end of the month, you will likely be well over threshold, so you should consider treatment. 

Green apple aphids continue to build in untreated orchards. As growth slows and terminal buds set, the pressure from this pest will decline.

Apple maggot trap catches continue to be very high in abandoned sites. Growers who are not trapping, should continue to control for this pest. Those trapping for it should be on the alert.

White apple leafhopper nymphs are visible in apples.

European red mites and two-spotted spider mites - Predators are abundant and providing control in many apple orchards. Bronzing is occurring in some blocks where harsher insecticides have been used. The threshold for this time of the year is 15 mites/leaf in apple, sweet cherry and plums and closer to 25 mites/leaf in tart cherry.

Disease:

Cherry leaf spot - Additional leaf spot continues to show up in area tart cherry and a few sweet cherry orchards. Post harvest sprays of Bravo will be very important for most tart cherry orchards. Sweet cherry growers with leaf spot should strongly consider a post harvest spray, too.

Sooty blotch/Fly speck - With all the heat and wet weather this season, fresh market apple growers are strongly advised to apply at least one spray to control this disease complex.

Brown rot - With peach harvest here growers should control for this disease, particularly if shelf life is critical for their crop.

Phomopsis fruit rot - Alan Jones diagnosed this rot in tart cherry orchards this past week. The light brown colored rot spreads throughout the fruit leaving behind a ring like pattern. Pycnidia (black fruiting bodies on the surface of the fruit) are also commonly present, though not always. Brown rot will not have pycnidia.

Miscellaneous:

Orchard Sampling: Growers should take leaf samples in the first half of August. Soil samples can be taken at any time now. Nematode samples should be taken in September as soil temperatures need to drop from where they are now before they can be taken. For additional information on collection of samples, either contact the NWMHRS or your county Extension office.

Predicted Apple Harvest Dates for NW Michigan (based on weather data from the NWMHRS):
 

Variety       Full Bloom Date        1999         Average

McIntosh        May 9                  Sept. 5        Sept. 18

Jonathon        May 10                Sept. 26        Oct. 4

Red Del.        May 11                  Oct. 3          Oct. 10

These dates are slightly different than previously published dates due to errors in the weather data. The McIntosh date, in particular, is much earlier. The previously published date was September 14^th. Sorry for any inconvenience this may have caused.

Guidelines for acceptable ranges for start index and firmness for long-term CA storage of major apple fruit varieties in Michigan

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Variety           Starch-iodine Index               Firmness (lb)

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McIntosh                   4 - 6                                14.5 - 15
Jonathan                   3 - 5.5                              15.5 - 16
Jonagold                   3 - 5.5                              15 - 16
Empire                     4.5 - 5.5                            16 - 17, 18-19 for export
Red Delicious           2.5 - 4                               17 - 18
Golden Delicious       3 - 5                                 15 - 17
IdaRed                     3 - 4                                  14.5 - 16
Mutsu                      3 - 4.5                               16 - 17.5
Law Rome                3 - 5                                  18 - 19

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Re-Cycling Container Program Ends

Per Hamilton Farm Bureau, the re-cycling container program will be ending August 19^th. Receiving hours are 10-3 p.m. Tuesday, Wednesday and Thursday. The chipper will no longer take drums, pails or poly tanks.

Pesticide Update

PennCap-M & Guthion Update

• As a result of the Food Quality Protection Act (FQPA), EPA has canceled virtually all fruit and vegetable uses of PennCap-M. The PennCap-M tolerance will be maintained for 1999, so use remains legal for the '99 season. Other details are not yet known.

 
• EPA and Bayer announced Guthion changes*. Beginning in 2000, the following changes are being made to the Guthion label:

• Reduce maximum yearly use from 6 to 4.5 lbs a.i. (12 to 9 lbs Guthion 50W).
• Increases pre-harvest interval (PHI) to 21 days if last application is greater than 1 lb a.i. (2 lbs of 50W).
• Prohibits chemigation or application by fixed-winged aircraft.

• Reduce maximum yearly use from 6 to 4.5 lbs a.i.
• Prohibits chemigation or application by fixed-wing aircraft.

• Reduces maximum yearly use from 4.5 to 3.375 lbs a.i. (9 to 6.75 lbs Guthion 50W).
• Prohibits application by chemigation or fixed-wing aircraft.

• All non-tree crop re-entry intervals except for mowing, irrigating and scouting are extended from 48 hrs to 4 days in our climate (5 days in drier climates).
• Prohibits application by backpack or hand-wand sprayers.

• Information provided by Dan Digiacomandrea, Bayer

Retain can delay fruit maturity by 7-10 days. This may help growers in the scheduling of harvest, reduce preharvest drop, enhance storage quality and allow for ripening in cooler conditions and thus improve fruit color.

Retain should be applied 4 weeks prior to anticipated harvest for long-term storage potential (see predicted harvest dates). Applications made either too early or too late can significantly reduce efficacy of the product.

We are currently in the window for Retain applications at the NWMHRS. Be sure to include the proper surfactant to obtain optimum response -- Silwet L-77 or Sylgard 309.

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

			GDD	Total Base		GDD	Total Base
Date	Max	Min	50	50		42	42

7/16/99	89	71	30.00	1266.95		38.00	2000.54
7/17/99	81	68	24.50	1291.45		32.50	2033.04
7/18/99	80	59	19.50	1310.95		27.50	2060.54
7/19/99	78	61	19.50	1330.45		27.50	2088.04
7/20/99	81	61	21.00	1351.45		29.00	2117.04
7/21/99	73	66	19.50	1370.95		27.50	2144.54
7/22/99	84	67	25.50	1396.45		33.50	2178.04
7/23/99	84	67	25.50	1421.95		33.50	2211.54
7/24/99	86	68	27.00	1448.95		35.00	2246.54
7/25/99	81	67	24.00	1472.95		32.00	2278.54
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

CIAB Weekly Production Reports can be accessed at the following web address

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

Last Revised:8-4-99