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Northern Michigan FruitNet 2009
Weekly Update
NW Michigan Horticultural Research Station

Nikki Rothwell District Horticulturist

Erin Lizotte District Fruit IPM/IFP Agent

Bill Klein Farm Mgr, NWMHRS

Duke Elsner Agricultural & Regional Viticulture Agent

May 5, 2009

GROWING DEGREE DAY ACCUMULATIONS AS OF May 4th  AT THE NWMHRS

Year	2009	2008	2007	2006	2005	2004	19yr. Avg.
GDD42	223	267	295	384	282	213	250.9
GDD50	85	124	120	179	118	79	108.2

 

Growth Stages at NWMHRS (5/4/09- 1:00pm)

Apple:  McIntosh & Red Delicious – Tight cluster

              Gala & Yellow Delicious – Tight cluster

Pear:  Bartlett :  Green cluster

Sweet Cherry:  Hedelfingen: Early white bud

                        Napoleon: Early white bud

                        Gold: Late bud burst

Tart Cherry:  Early bud burst

Balaton:  Late bud burst

Apricot:  90% Bloom

Plum :  Bud burst

Grapes:  Early bud swell

 

Weather

The weather has been slightly warmer during the days this week, but nights remain cool.  We have accumulated 223 GDD base 42 and 85 base 50—a considerable jump from last week.  We have had no rainfall since 26 April when we had just under a half inch of rain.  Overall, things are pretty dry in the north, but the snow has finally melted.  Rain is predicted for later in the week.

 

Crop Report

Pears are at green cluster.  All apples are at tight cluster.  Montmorency are at early bud burst and Balatons are at late bud burst.  Hedelfingen and Napoleon are at early white but and Golds are at late bud burst.  Apricots are at 90% bloom.  Chardonnay vines are still at early bud swell.  Winter injury is showing up in sweet cherry in lower lying areas, and a few orchards have a bit of tip dieback.  Mouse damage is visible in many blocks.  Growers are still pruning, and lots of trees have been planted this week.

 

Pest Report

Apple pests are showing up in the region as well as in the Research Station trap line.  Spotted tentiform leafminer are beginning to emerge, and the first Oriental fruit moth was caught in a station trap over the weekend (we will have to wait until we achieve sustained catch for biofix).  Oblique-banded leafroller larvae are out in small numbers, and European red mite nymphs have been observed.  Additionally, the first rosy and green apple aphids have been observed.  Reports from Lansing showed the first plum curculio catch in apple at 170 DD50, the north region is currently at 85 DD50.  As we move through the week, rain is in the forecast and based on a biofix of 4/25 (Macintosh green tip), apple tissue should be kept covered as scab spores are maturing quickly and 9% discharge is forecasted by 5/12.  Be sure to keep tissue covered during the wet period.

 

In cherry, we are catching green fruitworm in the Station trap line, where we had an average of 19 moths per trap.  Oil applications for San Jose Scale are going on sweet cherry before white bud or popcorn.  East Lansing researchers reported their first trap catch of plum curculio in cherry at 170 DD50.  Applications for European brown rot should be applied in two applications,  one at white bud and one at bloom on susceptible varieties (Balaton, Meteor, and occasionally Montmorency).  American brown rot blossom sprays will be going on soon with recommendations for application at 10-20% bloom.  Growers should be vigilant this year due to the high infection levels experienced in sweet cherries during the 2008 season.  Infection at white bud is rare, but may occur where a large number of brown-rot infected fruit are present from the previous season and we have prolonged periods of warm (above 60°F), wet weather.  If these conditions occur in unprotected orchards, use a maximum application of Indar or another sterol inhibitor 24-48 hours after the beginning of wet weather and continue at 2-4 day intervals while wet, rainy weather continues through bloom.  Remember a Rovral application may be made to fight resistance development but should be applied at 75% bloom, as Rovral does not redistribute well and works best on open flowers.  Do not apply Rovral past petal fall.

 

The grape trap lines are out at four sites around the northwest region.  We will be looking for potato leaf hopper and grape berry moth over the coming week.  Delayed dormant fungicide applications (at or before bud break) can kill fungi and insects that overwinter on the vine.  Dormant applications of lime sulfur, copper, or sulfur directly to the codon will reduce the inoculum of Phomopsis, powdery mildew, black rot, anthracnose, and mites.  Liquid sulfur formulations tend to work better than powdered sulfur.  Do not apply lime sulfur to green tissue, and be sure to check varietal susceptibility to fungicides on page 130 of the Michigan Fruit Management Guide.

 

EUROPEAN BROWN ROT

Nikki Rothwell, District Horticulturist, MSU-E

Erin Lizotte, District IFP/IPM Educator, MSU-E

 

As we move into bloom, be on the look out for cool, wet weather favorable for European brown rot to invade tart cherries.  Although the pathogen (Monilinia laxa) rarely infects Montmorency, it can be a problem in years under the right conditions.  Montmorency trees infected with European brown rot are often found in low areas of the orchard or along hedgerows, locations that do not dry off quickly.  This pathogen is a major disease in other cultivars like Meteor, English Morello, and Balaton. 

 

European brown rot infects and kills blossoms and spurs when wetting events last for a day or more.  The infected blossoms turn brown, and the leaves are also killed by the pathogen.  Eventually, the pathogen moves into the spur and causes a systemic infection.  Cankers form at the end of the infected spurs, which can infect the tree again in the following season.

 

To control this disease, two fungicide sprays should be applied; the first spray is at the popcorn stage, followed by a second spray seven days later.  Indar at the 2 oz rate is the most efficacious fungicide for controlling European brown rot.  Pruning the infected spurs during dormant months will reduce inoculum for the following season. 

 

 

SIGN UP NOW FOR THE GRAPE IPM SCOUTING REPORT

 

We will again be scouting the region for pest and diseases of winegrape during the 2009 season.  This newsletter includes relevant horticultural and management information throughout the season based on current, regional conditions.  To sign up for the report, e-mail Steve VanTimmeren at vantimm2@msu.edu.

 

 

WEBSITES OF INTEREST

Insect and disease predictive information is available at:
http://www.enviroweather.msu.edu/home.asp  

60 Hour Forecast
http://www.agweather.geo.msu.edu/agwx/forecasts/fcst.asp?fileid=fous46ktvc

Information on cherries is available at the new cherry website:
http://www.cherries.msu.edu/

Fruit CAT Alert Reports
http://www.ipmnews.msu.edu/fruit/

This issue and past issues of the weekly FruitNet report are posted on our website at: http://www.maes.msu.edu/nwmihort/faxnet.htm

ACTUAL AND PREDICTED DEGREE-DAY
ACCUMULATIONS SINCE MARCH 1, 2009

 

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

Last Revised: 5-5-09