SW Michigan Fruit Update

Check the Index for earlier postings

April 25, 2006

Mark Longstroth, Bill Shane, Al Gaus

Weather

The last two weeks were warm and mild.  Temperatures were often in the upper 70s and above 50 at night.  Growing Degree Day accumulations are a week ahead of normal for this time of year.  We are caught up with 2005.  We are still behind 1998 and 2000 by a week or more.  Little rain has fallen over the district this spring and conditions are becoming very dry.  Soil temps have fallen into the 50s.  This week’s forecast is for cooler weather, with highs near 60 and lows about 40. This should slow down development. There is a chance of frost Wednesday and Thursday mornings.  See the new Weather for IPM decisions in Michigan site at http://www.enviroweather.msu.edu/home.asp.  The weather stations in the table are linked to the respective pages at this new site.

Southwest Michigan Growing Degree Day Totals  March 1 through April 23, 2006				Grapes, from April 1
Location	GDD 42	GDD 45	GDD 50	GDD 50
Scottdale:	334	260	162	132
SWMREC:	345	261	159	127
Bainbridge:	358	274	165	131
Hartford:	308	230	139	117
Lawton (est.)	373	287	178	137
South Haven NEW
Grand Junction:	341	262	161	124
Fennville:	289	216	127	99
Lawton site is estimated using Bainbridge data for March.

Tree Fruit

Tree fruits are blooming.  Bee activity has been heavy.

Apricots are in the shuck.  Early varieties are at shuck split.

Peaches are petal fall. Bloom was very heavy.  Some growers are blossom thinning.  We caught the first Oriental Fruit Moth last weekend.  We set Biofix as April 16 with a GDD of 180 Base 45 at SWMREC.  We are about 80 GDD past Biofix.  Egg hatch should begin about 150-170 GDD base 45 after Biofix and chemical controls are focused on egg hatch.  We will pick up about 5 GDD per day next week so this spray should be applied in about a week.  Growers planning to use pheromone disruption should have their dispensers out now.  Western flower thrips have been a problem in the past during bloom and droughty conditions.  These small insects feed on the developing fruit in the shuck.  Growers may want to target sprays for this pest when bloom ends and bees are removed from the orchards.  Be aware of tarnished plant bug, which feeds on the flowers of weeds. Mowing can drive them into the canopy where they will feed on the fruit, deforming it.

Sweet cherries are at petal fall.  Sweet cherries are very susceptible to brown rot.  Cherry leaves are unfolding so growers need to protect against cherry leaf spot.

Tart cherries: Montmorency cherries are in full bloom.  Balaton cherries are less advanced at early bloom.  Cherry leaf spot is concern as leaves begin to unfold.  Growers can cherry leaf spot and several other pests at the Weather for IPM decisions in Michigan site.

In Plums, Oriental plums are in the shuck. European plums buds are at full bloom.  Black knot control needs to be maintained if we have rain. 

Apples are at pink.  Early varieties such as Ida Red are opening.  Several wetting events have been marginal infection periods for apple scab.  Scab symptoms from these rains should be appearing but none were found Monday.  Growers can monitor wetting periods for scab and fire blight infections at the Weather for IPM decisions in Michigan site.  The dry conditions have kept fire blight cankers from doing much oozing.  We are now trapping Redbanded Leafroller and Oriental Fruit Moth.  Leafroller should be feeding in shoot tips and flower clusters, but none were found Monday.  European red mite should be hatching and Rosy apple aphid should be out.  Growers who did not control these pests at pink should plan their post bloom sprays. Spotted Tentiform Leafminer should be flying.

Pears are in bloom. Growers need to monitor Pear Psylla and protect against pear scab.

Small Fruit

Blueberries are at early pink bud and early varieties are beginning to bloom. Leaves are unfolding.  Mummy berry mushrooms are hard to find in this dry weather.  A mystery beetle was found feeding on buds in Van Buren County. This beetle appears occasionally at and before bloom. It looks like a small black Japanese beetle about 3/8 inch long. It is a member of the genus Hoplia, a flower beetle.  It is attracted to white and feeds on flower buds.  A mild insecticide before bloom begins should knock them down.

Grape buds have burst but the leaves have not unfolded yet.  Some growers applied dormant sulfur and copper sprays to reduce overwintering phomopsis.  Otherwise growers will need to apply protective spray soon. Flea beetles are out in large numbers and have caused a lot of damage in some areas.  Growers should also be scouting for cutworms.

Strawberry flower buds are emerging from the crown.  Bloom has begun in some areas of Berrien County.

Raspberries leaves are emerging on blackberry and summer raspberry canes.  Fall raspberry shoots are 4 to 6 inches tall.

Cranberry buds are beginning to swell and some areas of the beds are greening up.

Miscellaneous

Growers are planting trees, and report that soils are very dry.

The next Monday Fruit Update meeting will be, Monday May 1, at the Fruit Acres Farm in Berrien County, at 5 PM.