SW Michigan Fruit Update

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Southwest Michigan, 2007 Growing Season

Mark Longstroth, Bill Shane, Greg Vlaming

2007 Weather in Southwest Michigan

2007 will be remembered for the Easter Freeze and the summer drought.  Most of the winter was relatively mild.  An early period of cold, snowy weather occurred in early December 2006.  This was followed by mild weather with temperatures above freezing during the day through January.  There were reports of early bud swelling in peaches in Southern Berrien County in late January.  A period of very cold weather occurred in February.  Temperatures were close to zero and below several times in the first three weeks of February.  This caused some damage to peach fruit buds in orchards away from Lake Michigan.  Soils had good moisture early.  Late March and early April were warm, with highs into the 70s and lows well above freezing.  Warm weather caused rapid fruit bud development with bloom beginning in apricots, peaches and sweet cherries in early April with record high temperatures on Tuesday April 4 followed by frigid weather with snow and highs near freezing for the next four days. Lows near 20 occurred on Easter weekend Friday and Saturday (April 6, 7).  Low temperatures were a few degrees higher close to Lake Michigan and the extreme cold did not last as long.  Many fruit crops were damaged by the freeze.  Most of this event was cold and windy--a classic advective or wind freeze.  Another radiation freeze (clear, still, relatively dry) occurred on Tuesday morning April 10, with lows in the low 20s close to Lake Michigan and below 20 away from Lake Michigan.  The low temperatures away from the lake also lasted much longer than closer to the lake.  This frost was very variable and many exposed sites, normally frost-free sites, had more damage than usual.  States south of Michigan experienced severe cold damage to fruit crops.

Growing Degree Day (GDD) accumulations in 2007 were well above average.  Early accumulations were only a few GDD behind 2000 and 1996, two fairly recent early warm years.  Weather in late April and May were generally warm dry periods, with highs often in the 80s, interspersed with cool rainy periods so the soil moisture levels were good.  Thunderstorms and rain on the morning of May 9, 2007 caused infection by the common early season fruit diseases.  This was the only and last significant wetting event of the spring.  It was a long warm wetting event with fog overnight followed by heavy dew.  The resulting wet period spanned over 24 hours of leaf wetness and an average temperature of 60F.  Afterwards, precipitation was spotty for the spring and early summer of 2007.  For May through July, significant rain of about an inch seemed to come every 2 to 3 weeks but temperatures were generally hot, so that rainfall did not did not keep up with plant water use.  By June, soil conditions were extremely dry and plant growth was suffering.  August brought heavy rain events that caused some flooding problems.  Harvest seasons in 2007 were generally 10 days to 2 weeks ahead of normal.

Growing Degree Day Tables for September 16 and September 30 are located at the end of this report.

Tree Fruit Insect Pests

Oriental fruit moth biofix was April 21 at 230 GDD from March 1 at SWMREC.  The second generation of oriental fruit moth was biofixed on June 17 at 1312 GDD.  Codling moth was biofixed on May 9 at 325 GDD50 at SWMREC. The second generation of codling moth was biofixed on two different dates, June 14 and 21 depending on the strength of flight or trap catch.  Area growers generally seemed to do a good job controlling the beginning of the first flight allowing them to forgo a spray until trap numbers climbed above the biofix threshold of 5 moths per trap.  Obliquebanded leafroller biofixed on May 28 at 942 GDD42 at SWMREC.

 

Tree fruit

Apricots were blooming during the Easter freeze and suffered a complete loss of crop.

Peach fruit bud loss due to winter cold in the negative teens was reported in some varieties and on lower, colder sites, especially in counties away from Lake Michigan before the Easter Freeze but the main production region (Berrien County) suffered little damage.  Peaches were showing first pink and bloom had begun in Berrien County when the Easter Freeze occurred.  Open flowers were killed by the freeze but most closed flowers survived.  A good crop of peaches survived in Berrien County but further from the lake there were few peaches.  Thinning was required in many blocks.  Drought caused small fruit size for varieties in the Garnet Beauty to Red Haven window, but later varieties generally sized well following the rains of August. Oriental fruit moth, tarnished plant bug and plum curculio caused some damage after fruit set but no big problems.  Peach leaf curl, peach scab and peach mildew were not significant problems.  There was a strong demand for Michigan peaches and movement was generally brisk thought the harvest season.  Western flower thrips and San Jose scale did cause surface blemishing and brown rot was a problem at some times as Berrien County received several severe storm and large amounts of rain in late in the summer. 

Tart cherrieswere at bud burst for the Easter freeze. Growers reported heavy losses in Allegan and Van Buren counties.  There was an extended late bloom with good fruit set.  Overall the crop was variable across the region, with some growers reporting a good crop.  It appears that the crop has been reduced by 60%.  Growing conditions following bloom were very dry so that cherry leaf spot was not an issue.  Copper was used for leaf spot control and was very effective under the dry conditions.  Harvest began early and was over before July 1.  Fruit quality at harvest was good although fruit size suffered from the lack of moisture.  Most cherry trees in the area retained their leaves until significant rains in August renewed leaf spot infections.  Tart cherries have the potential for an excellent crop in 2008.

Sweet cherries were at tight or open cluster for the Easter freeze. Orchards near Lake Michigan suffered little damage.  Orchards away from Lake Michigan suffered a complete crop loss.  It became apparent that the radiation freeze on April 10^th was responsible for these poor crops in the lower parts of the tree.  Damage was very variety specific.  Cultivars on dwarfing rootstocks were more advanced and suffered more damage.  Orchards in good sites close to the lake had a good crop of sweet cherries. 

In Plums, winter cold caused significant tree damage to a few Stanley plum plantings. One site, defoliated early in 2006, must have been more susceptible to winter cold.  Tree trunks showed severe browning above 6 inches, and many of the young shoots were already shriveling in March.  Another site collapsed during the heat of the summer and showed trunk damage and bark splitting.  European plums were at tight cluster during the freeze and suffered no damage close to the Lake and light damage away from the Lake.  Oriental plum flowers were blooming at the time of the freeze and damage was more variety specific with severe damage in early blooming varieties and at sites away from the lake.  Some growers reported a light crop but generally there were no Oriental plums in SW Michigan in 2007.  The crop was spotty, and demand was poor for processing plums during the harvest season.  Fresh market sales were good.

Apples were at half inch green to tight cluster or even first pink for the Easter Freeze.  Damage was widespread and again was due to the stage of development and distance from the lake.  Early blooming varieties were severely affected in Van Buren County with less injury reported in Berrien and Allegan counties.  Varieties such as Gala, McIntosh, and Jonathan had light crops due to the freeze.  Later developing varieties suffered much less damage.  Cluster leaves, which emerge before the flowers showed significant injury such as crinkling and other distortion.  Growth in the early spring was excellent and fruit size was good.  The summer drought caused few problems.    

Apple bloom began the week of April 23 and continued through mid May.  There were fireblight infection periods at the beginning and end of bloom.  Warm weather as bloom began allowed initial fire blight infections in early blooming cultivars.  Another wave of symptoms appeared after the first but before the predicted date for a late infection on May 9.  This infection was believed to be from trauma during to an extremely warm and windy period due to sand wounding tender green tissue.  Several counties in Michigan had a section 18 for the use of Agry-Gent, a gentamycin antibiotic to control fire blight where streptomycin resistance in the fireblight bacteria was documented.  According to EPA regulations, Agry-Gent could not be the first antibiotic applied. Agry-Gent appeared to provide good control.  Some growers did have fire blight and in some cases it was severe, usually in orchards with a history of fire blight.  Because of the dry season apple scab was not generally a problem.  Oriental fruit moth and codling moth were not severe.  More and more growers are using alternatives to organophosphate insecticides and reporting good success.  It was feared that we would have a third generation of codling moth but there was not a strong flight at the end of August or in September. European Red Mite was a problem for many requiring treatment in late July.  Fruit size was good for some varieties despite the mid season drought.  Harvest began about two weeks early. 

Pears buds were at tight cluster during the Easter freeze and so damage was not severe.  Pear suffered no major problems with insects or diseases.

Small fruit

Blueberries were also affected by the freeze.  A heavy crop was expected since 2006 was a year with good moisture allowing many fields to set a heavy crop of fruit buds.  Fruit buds were swollen and are starting to burst in early varieties.  Following the freeze early developing varieties showed browning of the fruit buds.  Leaf buds at the shoot tips had begun to grow and exposed green leaf tissue were killed and this resulted in the death or stunting of leaves and shoots just below the flower buds.  Bluecrop showed this trait more than other varieties and many Bluecrop fields had a heavy bud set.  This resulted in small fruit and reduced yields because of the low leaf to fruit ratio.  Blueberries within 10 miles of the Lake generally suffered little damage from the freeze.  Mummy berry was a problem in some fields.  The dry conditions kept fruit rots to a minimum.  Insect problems were not generally significant.  Cranberry fruit worm and cherry fruit worm emerged during bloom.  Cranberry fruit worm seemed to emerge later than normal and was a problem in some fields where late controls were not applied.  Yields were generally heavy where there was little or no freeze damage.  Drought reduced fruit size in many unirrigated fields.  Prices were strong due to high demand.  Growers irrigated heavily during the summer and generally bushes were in good health as the 2007 ended.

Grapes: During the Easter freezes Concord buds were at early swell and vinifera grapes at scale crack.  Grapes were bleeding from fresh pruning cuts indicating that the sap was up and the buds were active.  Losses due to the freeze were widespread but very variable due to site exposure, bud development and distance from the lake.  Initial damage estimates of 50 % loss to the primary buds.  As a reaction to several years of heavy losses to early spring frosts many growers had left many buds during pruning so there was still a good crop potential.  Many high sandy sites that normally do not freeze were more advanced and suffered more damage due to the cold wet windy conditions during the Easter Freeze.  Lower, less advanced sites suffered little damage and had heavy crops.  Additionally the damage was more than expected from the grape freeze injury tables developed in Washington State and were more consitant with those reported by Stan Howell for wet grape buds.  There were relatively few disease infection events early in the spring and the dry summer made for an almost disease free year.  Grape berry moth was not a big problem.  The drought did have the effect of shriveled and dropped berries in July, but the return of rain in Berrien County in late July caused a rebound and the crop suffered little damage.  In fact, the heavy rain in August caused berry size to double at that time and 2008 was a very heavy crop.  I was more than a little embrassed since I had predicted only half a crop after the Easter freeze.  Heavy rain in August also caused botrytis bunch rot in early varieties.  September and October were generally sunny and dry.  Niagara harvest began before Labor Day and continued through September 15.  Concord harvest began September 17 and continued through mid October.  Yields were excellent in most sites.  Wine grape quality was excellent and 2007 should be a vintage year. 

Strawberries were putting out new leaves and the trusses were visible in the crowns for the Easter Freeze. Covered strawberries were not severely damaged by the freeze, but many fields were damaged and showed poor growth after the freeze.  Harvest season was quick due to the heat.  Many plantings looked rough after the harvest season.  Regrowth in many field suffered from drought and potato leafhopper damage.  Drought stressed fields will do poorly next year.

Raspberry floricanes were damaged by the freeze.  The green tissue of actively growing buds was killed.  The shoots of fall bearing raspberries that had emerged before the freeze were singed and damaged.  Some varieties were severely affected by winter cold snap (i.e. Prelude).  Summer raspberry yields were affected by both the freeze and drought conditions into late July.  Fall bearing raspberries generally did well.   Blackberries were severely damaged by winter cold (early February) and the Easter freeze.  Generally there was good regrowth and fruit yields were good.

 

Southwest Michigan Growing Degree Days (GDD) Totals March 1 through September 16, 2007				Grapes April 1
Location	GDD 42	GDD 45	GDD 50	GDD 50
Scottdale	4251	3745	2948	2841
SWMREC:	4112	3609	2819	2721
Bainbridge:	4015	3519	2713	2613
Hartford:	3849	3355	2580	2485
Lawton:	4202	3701	2902	2800
Grand Junction:	4331	3894	2959	2840
South Haven:	3897	3394	2620	2527
Fennville:	3837	3334	2563	2483

 

 

Southwest Michigan Growing Degree Days (GDD) Totals March 1 through September 30, 2007				Grapes April 1	2007 Precip
Location	GDD 42	GDD 45	GDD 50	GDD 50
Scottdale	4595	4047	3183	3066	29
SWMREC:	4456	3911	3053	2955	27.1
Bainbridge:	4336	3801	2959	2859	27.7
Hartford:	4158	3623	2787	2692	27.8
Lawton	4537	3992	3127	3024	21.9
Grand Junction	4523	3971	3109	3012	22.1
South Haven	4350	3711	2868	2775	26.5
Fennville:	4154	3606	2772	2692	21.5