SW Michigan Fruit Update

Check the Index for earlier postings

Southwest Michigan, May 8, 2007

Mark Longstroth, Bill Shane, Greg Vlaming

Weather

Last week was windy.  It was pleasant with lows in the mid 40s and highs in the upper 60s and 70s.  Cool dry windy conditions have dried the soils.  This week’s forecast is for warm weather with lows in the 50s and highs in the 70s.  Thunderstorms are possible for the rest of the week.  Any rain over the next few days could result in a fire blight infection.  Cooler temperatures are forecast for the weekend.

Southwest Michigan Growing Degree Days (GDD) Totals March 1 through May 6, 2007				Grapes from April 1
Location	GDD 42	GDD 45	GDD 50	GDD 50
Scottdale	561	448	294	187
SWMREC	533	423	276	188
Bainbridge	529	423	277	176
Hartford	512	407	265	170
Lawton	600	487	329	209
Grand Junction	581	459	311	199
South Haven	502	399	261	168
Fennville	460	358	226	166

Tree fruit

Plants are leafing out rapidly and insects are active.  As stone fruit emerge from the shuck growers should scout for plum curculio. 

Peaches are near shuck split.  The peach crop looks better and better.  Large numbers of Oriental fruit moth adults are still being caught in pheromone traps.  Biofix was Saturday, April 21 at 230 GDD at SWMREC.  Pesticide sprays are targeted for egg hatch at 200 GDD base 45 after Biofix; which was Saturday.  The first generation of Tarnished plant bug adults are in the trees. 

Tart cherries are in the shuck.  There is still late bloom opening and most of these flowers look good.  Overall the crop looks light, but is very variable across the region, with some growers reporting a good crop.  With fruit approaching shuck split we are near the end of the application window for Chlorothanil.  Copper is an effective cherry leaf spot material.

Sweet cherries are in the shuck.  Early varieties and those on dwarfing rootstocks are emerging from the shuck.  Some growers report a good crop of cherries.  Sweet cherries should be protected from brown rot from bloom until harvest and the possibility of warm wet rains exist this week.  Copper should not be used on sweet cherries.  .

Plums are in the shuck.  Growers should be protecting against black knot and brown rot. 

Apples are blooming.  Early blooming varieties are in petal fall but Winesap and Rome are in full bloom.  Thunderstorms this week will likely cause fire blight blossom infections of open flowers.  We are updating our Code-A-Phones daily with fire blight conditions.  The quality of bloom varies quite a bit and growers should assess their crop in preparation for thinning sprays next week.  Apple scab symptoms should appear this week from the April 26 infection.  Now is the time to apply Apogee sprays to reduce fire blight and vegetative growth.  Growers can also check for apple scab and fire blight at the Enviroweather website. http://www.enviroweather.msu.edu/.   Oriental fruit moth is being caught in good numbers in pheromone traps.  Biofix was Saturday, April 21 at 230 GDD at SWMREC.  Codling moths were trapped on Saturday, May 5 in some locations.  Obilquebanded leafroller larvae are feeding in shoot tips.  European Red Mites are out and growers should be scouting for aphids.

Pears are petal fall.  Very little bloom remains but growers should protect against fire blight.  Pear scab is similar to apple scab and pear scab symptoms should appear this week as with apple scab.

Small fruit

Blueberries are blooming.  Mummyberry shoot strikes are appearing from the April 25-26 infection period.  Growers should check the new Blueberry IPM Newsletter at the MSU Blueberry Site.  Both cranberry and cherry fruit worms were reported caught in pheromone traps. Obilquebanded leafroller larvae are feeding on fruit buds.

Grapes: Concord shoots are about 3 to 4 inches long with several leaves out.  Vinifera grapes are from leaves opening to late swell.  Growers have been applying early season disease control materials.  This first fungicide spray is especially important for phomopsis control.  Growers should apply protectants before the next rain.  Be sure and check the MSU Grape website for scouting updates.

Strawberries are at first bloom.  Many plantings look rough and growers have been fertilizing and irrigating.

Raspberries: Summer raspberry flower buds are visible in some varieties.  Some varieties were severely affected by winter cold snap (i.e. Prelude).  Fall raspberry shoots are about 6 inches high.  Blackberries were severely damaged by winter cold (early February) and the Easter freeze.  Advanced shoots were damaged or killed but new growth is emerging.

Cranberry buds are beginning to swell.

Miscellaneous

Soils are dry and growers should irrigate if they can.  Some fruit plantings from last year look stressed this may be a result of the winter cold snaps.  Herbicides applied to dry soils or drought stressed weeds are less effective.

The next Monday Fruit Update meeting will be Monday May 14, 5 pm, at the Fruit Acres Farm in Berrien County.  We will discuss apple thinning.  The next Grape IPM meetings are Thursday May 24.  The morning meeting will be from 10 AM to noon at the Cronenwett Farm Shop at 70123 28th Street east of Lawton. The afternoon meeting will be at 2 PM in the Berrien County MSU Extension Office at the Southwest Michigan Research & Extension Center.  These meeting are co-sponsored by National Grape Cooperative and MSU Extension and are open to all grape growers.  There are RUP credits available for both the Monday Fruit Updates and the Grape IPM meetings.