SW Michigan Fruit Update

Check the Index for earlier postings

Southwest Michigan, April 20, 2009

Mark Longstroth, Bill Shane

Weather

Warm weather late last week with highs near 70 and lows around 50 caused rapid growth.  Last week there were two rain events.  The first was April 13-14 and brought a third to a quarter inch of rain.  Sunday, April 19, brought a large-scale rain event that has left about an inch of rain. This rain was a wide spread scab infection event.  Bloom has begun in early blooming fruit crops.  We would need temperatures below 25F to cause freeze injury to most crops.  Warm conditions are expected to return Wednesday and I expect rapid crop development later this week.

You can find Growing Degree information for Southwest Michigan that information at the Enviroweather website.  There were problems with that website earlier this week but they appear to have been solved.  Here is a link a table of SW Michigan’s Growing Degree-Days base42 from March 1 to April 19, 2009, we are ahead of 2008, but behind earlier years from 2007 to 2004, here is a comparison of Growing Degree Days base 42 to April 19 in past years.

Southwest Michigan Growing Degree Day Totals March 1 through April 19, 2009				Grapes, from April 1
Location	GDD 42	GDD 45	GDD 50	GDD 50
SWMREC:	188	132	68	28
Fennville:	152	105	52	27

 

Tree fruit

Bloom has begun in early fruits such as apricots, cherries and Japanese plums. 

Apricots are blooming.

Peaches buds are at red caylx and leaf tips are emerging.  Copper sprays can be used to reduce bacterial spot by reducing the bacterial population. No more than 1.5 pounds of metallic copper should be used at this time. There is still an opportunity to apply oil sprays to reduce San Jose scale, use 1.5 gallons of oil per 100 gallons of water and spray to runoff, complete coverage is important.  Symptoms of peach leaf curl should not appear for several weeks when leaves have fully emerged. 

Sweet cherries buds have opened and are generally at tight cluster.  Early varieties on dwarfing rootstocks are blooming.  It is well past time for copper on sweet cherries.  Copper will cause damage to sweet cherry leaves and fruit.

Tart cherries buds are at green tip. In southern Berrien County buds are opening.  ‘Balaton’ cherries are at bud burst.  We are at the end of the window for copper on sweet cherries dormant spray to reduce bacterial canker.

In Plums, European plum buds are at tight cluster.  Oriental plums are beginning to bloom. 

Apples are at tight cluster.  This weekends rain was a widespread apple scab infection event.  Scab spores were caught in good numbers during the rain.  Growers who did not have apple scab fungicides on their orchards should use materials with back action.  Because of the resistance to SI materials such as Rally and Indar growers may want to use materials with a different mode of action.  Vanguard and Scala are good materials with about 48 hours of back action.  These are systemic materials that are absorbed into the plant and redistributed through out the leaf, and work well under cool conditions.  SI materials such as Rally and Indar growers should use at full rates for maximum back action.  There is no insect activity to report.  Oil sprays to control aphids, mites and scale can be delayed until pink.  If you plan in using oil you should avoid using sulfur of Captan at this time.  Symptoms for this scab infection event should show up at the end of the month.

Pears buds have opened and are at green cluster.  Pear scab is a concern as there is green tissue out and the infection conditions are similar to apple scab.  Pear growers can use the apple scab model at the enviroweather site to track pear scab.  Pear Psylla eggs are hatching.

Small fruit

In small fruit, now is the window for lime sulfur applications in blueberries, grapes and brambles to suppress diseases that overwinter on the plant.

Blueberry fruit buds are bursting in Berrien County and leaf buds have 1/8” green tissue exposed.  Mummyberry mushrooms should be out but I have not found any.  The weekend rain event was a mummyberry infection event.  Growers with Putnam scale problem may want to use dormant oil sprays to reduce this pest.  Avoid using oil sprays if you have recently used lime sulfur as the oil and sulfur can cause plant injury if green tissue is present.  The Michigan Blueberry IPM Newsletter is posted at the MSU Blueberry IPM Update Newsletter.  The first Blueberry IPM Update meeting is planned for May 13 at the Bodtke Farm at 01240 57^th Street, west of Grand Junction MI.

Grape buds are generally tight but terminal buds are at scale crack.  Growers are tying canes.  Here is a link a table of SW Michigan’s Growing Degree-Days base50 from April 1 to April 19, 2009.  There will be a Grape IPM Meeting at SWMREC on April 23 6 to 8 PM.

In Strawberries, new leaves have emerged and flower trusses are still in the crown.  I expect that the flower trusses will begin to emerge this weekend.

Raspberries are at and quarter inch green can be found.  You need to reduce Lime Sulfur rates after the leaves emerge.  Blackberries show little movement.

Cranberries are dormant.

Miscellaneous

Growers are pruning and clearing brush.

The Fruit Code-A-Phones in Van Buren (269) 657-8217 and Berrien (269) 944-4126 ext 1, are being updated.  The next Monday Fruit IPM Update meeting will be, Monday April 27, at the Fruit Acres Farm in Berrien County.