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 |
July 7, 2009
GROWING DEGREE DAY ACCUMULATIONS AS OF June 8th AT THE NWMHRS
Year |
2009 |
2008 |
2007 |
2006 |
2005 |
2004 |
19yr. Avg. |
GDD42 |
1331 |
1368 |
1713 |
1647 |
1669 |
1293 |
1485.6 |
GDD50 |
748 | 792 | 1069 | 987 | 1045 | 711 | 893.9 |
Growth Stages at NWMHRS (7/7- 8:30 a.m.)
Apple: McIntosh – 31 mm fruit
Yellow Delicious – 30 mm fruit
Gala – 30 mm fruit
Red Delicious – 32 mm fruit
Pear: Bartlett: 23 mm fruit
Sweet Cherry: Hedelfingen: 21 mm fruit
Napoleon: 21 mm fruit
Gold: 19 mm fruit
Tart Cherry: 17 mm fruit
Balaton: 17 mm fruit
Apricot: 34 mm fruit
Plum: 23 mm fruit
Grapes: Late bloom
Weather Report
Temperatures have been all over the board lately. Last week, we had maximum temperatures in the 50’s and 60’s, the weekend warmed up into the 70’s, and we are back down into the 50’s and 60’s for the middle of this week. In terms of degree days, we have accumulated 1331 GDD base 42; the 19-year average for base 42 is 1486. For base 50, we have accumulated 748 GDD, and the 19-year average is 894. Obviously, we are a bit behind with these variable temperatures.
Crop Report
All fruit is sizing slowly due to the overall cool temperatures. Pears are at 23-30mm, and apricots are at 34mm (only 1mm size increase from last week). Apples range from 30mm-32mm. Montmorency and Balatons are at 17mm, and sweet cherries are at 19-21mm. Chardonnay is at late bloom. Strawberry harvest is predicted to end this Thursday.
Pest Report
In apples, we only caught one codling moth this week, down from 9 per trap last week. Spotted tentiform leafminer numbers are on the rise with an average of 29 per trap. Oriental fruit moth trap catch is down from 9 per trap last week to 1 this week. Oblique-banded leafroller are emerging in variable numbers depending on trap location, with an average of 7 per trap compared to 32 per trap last week. Green apple aphid populations have risen sharply at the Research Station this week, see the attached article for more information. Along with the wet weather, the apple scab model is predicting a heavy infection period in association with the wetting period that started on the July 1. Just under 100% apple scab ascospore dispersal is predicted based on a biofix of Macintosh green tip on 4/26.
We caught our first cherry fruit fly today at the Research Station. We are often the first place in the state to catch fruit fly so growers should utilize their on-farm trap catch or earliest regional trap catch (excluding the Research Station) to biofix. See the included article for more information in cherry fruit fly management. In cherries, American plum borer emergence appears to be tapering off with only 1 per trap this week (season long catch as follows: 37-6-15-7-9-1-1). Lesser peach tree borer continues to emerge with trap catches of 7-18-7-6 over the past four weeks. Greater peachtree borer continue to emerge for the third week in a row with an average of less than 1 per trap this week. As in apple, oblique-banded leafroller numbers are down in cherry with an average of 9 per trap, down from 27 per trap last week. Growers are reporting some plum curculio ovipositioning scars, but less than we would expect at this time. The first reports of American brown rot in sweet cherry clusters are coming in and large oblique-banded leafroller larvae are being reported in clusters. High rose chafer populations have been reported in some orchards. The cherry leaf spot model has predicted a moderate and high infection potential on July 1-2 based on the wet weather. Sour cherry yellows is showing up in many area tart cherry blocks, particularly in older trees.
In grapes we continue to catch grape berry moth in high pressure sites. Potato leafhopper are arriving in higher numbers. Some sights are experiencing high numbers of rose chafer. No reports of mildew as of yet.
PREDICTED APPLE CROP FOR 2009
The Michigan apple crop estimates were released in mid-June. The Michigan Processing Apple Growers Marketing Committee estimates the 2009 crop to be 23.4 million bushels with a good crop predicted for all varieties. The average Michigan crop is around 20 million bushels. The Frozen Food Packers Association Fruit Crop Guesstimate resulted in the following numbers by region in Michigan: West Central 15,630; Eastern 1223; Northwest 3291; Southwest 3018. The grand total for the state is estimated to be 23,162.
The National crop estimates for 2009 are as follows: Washington 138 million bushels; New York 29.5 million bushels; California 8.8 million bushels; Pennsylvania 10.9 million bushels, and Virginia 6.1 million bushels. The national total, including Michigan, is 247.5 million bushels.
DON’T FORGET THE GRAPE IPM UPDATE THIS FRIDAY, JULY 10TH!
This Friday, July 10th from 3-5 p.m. Larry Mawby will host Michigan State University Entomologist Dr. Rufus Isaacs at his tasting room located at 4519 S Elm Valley Road in Suttons Bay, Michigan. Dr. Isaacs will be discussing wine grape pest biology and management. Pesticide recertification credits will be available and there is no cost for this program. Following the educational session Parallel 45 Vines and Wines will provide bread and cheese to accompany the wines that attendees traditionally bring to share. We hope to see you there!
MONITORING AND MANAGEMENT STRATEGIES FOR CHERRY FRUIT FLY
Luís Teixeira, Entomology;
John Wise, MSU Trevor Nichols Research Complex;
Nikki Rothwell, MSU Northwest Horticulture Research Station;
David Epstein, MSU IPM Program;
Larry Gut, Entomology;
and Erin Lizotte, IFP/IPM District Educator
Cherry fruit fly overwinter as pupae and are developmentally ready to emerge as adults in late spring. Adult fly emergence depends on soil heat accumulation. Peak emergence is highly dependent on site-specific weather conditions. Much of the Michigan fruit growing region has had above normal precipitation and relatively low temperatures over the growing season, so cherry fruit fly emergence is proceeding slower than normal this year.
Monitoring adult cherry fruit fly flight is the key to effective management of this pest. Adult activity can be monitored using yellow sticky boards with ammonium bait. The yellow trap is most useful during the pre-oviposition period when newly emerged females are actively feeding. Traps should be placed on the south-facing side of the top of the canopy of trees in perimeter rows because most flies are expected to be immigrating from wild hosts outside the orchard. The native host of cherry fruit fly is wild black cherry. Optimally, traps should be checked twice weekly until the first fly is captured, then once a week thereafter until the end of the flight.
Identifying cherry fruit fly generally requires the use of a 10X hand lens. Adults are gray flies, approximately 5 mm in length. The most characteristic feature of the fly is the dark pattern on their wings with a broken band at the tip (Figure 1). These wing-banding patterns are used to differentiate between fruit fly species.
The greater the number of traps deployed per block, the greater the confidence level in basing treatment decisions on fly catch. Place at least two traps along borders that historically have been a source of infestation. Proper trap maintenance is crucial to trap effectiveness. Over time, the adhesive can be fouled by leaves, twigs, other insects and debris. Remove debris and insects each time traps are checked. The adhesive should then be evenly redistributed. In determining control treatment timing, on-farm fly catches should be used in conjunction with regional trapping information. Basing treatment decisions solely on regional information may lead to unnecessary insecticide applications. If you employ a good trapping program, a control treatment for CFF is not warranted until flies are captured on your farm. If flies are trapped on-farm, and a regional trap catch was recorded prior to the on-farm fruit fly capture, the treatment should be timed based on the earlier regional capture. This conservative approach is the best way to ensure that the control is applied prior to the flies reaching reproductive maturity and beginning to lay eggs. Chemical control of CFF is focused almost entirely on the adult, with the goal of preventing egg-laying.
Upon emergence, there is a 10 to 12 day period before female flies begin to lay eggs. During this time they are searching for nutritional sources needed to become sexually mature. After female flies complete this pre-oviposition period and have mated, they will seek out fruit for egg-laying. They lay eggs just under the skin of ripening fruit with a needle-like ovipositor, making visual detection of the puncture wound difficult to distinguish from lenticels on the apple surface. Fly larvae, called maggots, hatch from eggs within a week and begin to feed in the flesh of the fruit. Mature maggots drop out of fruit and enter the ground, where they pupate, starting the next generation’s life cycle.
Control of the cherry fruit fly has been traditionally achieved with organophosphate insecticides, like Guthion and Imidan (phytotoxic on sweet cherries), but some label or processor restrictions may limit their use near harvest. Carbamate and synthetic pyrethroid compounds like Sevin and Asana are also toxic to adult fruit flies, but are generally viewed to be moderately effective because they have a shorter field residual. There are several new reduced-risk and OP-replacement insecticide products that include cherry fruit fly on their labels. The neonicotinoids Actara, Provado and Assail are labeled for cherry fruit fly control. All three have performed well against cherry fruit flies in small plot field-performance trials. The Spinosyn compounds Delegate and Entrust are active on cherry fruit flies, but their need for ingestion by adult flies requires excellent spray coverage.
GF120 NF Fruit Fly Bait (spinosad) is registered on pome fruits for control of cherry fruit flies and is listed by the Organic Materials Review Institute (OMRI) for use in organic production. Because the primary route of entry is through ingestion, applying this product during the fruit fly pre-oviposition period is important for optimal performance. GF120 must be applied with specialized equipment, and is designed for low-volume application. The bait is not rainfast and should be re-applied after rain or heavy dew. Field efficacy data is encouraging, but we have limited experience with this novel tool to date.
The pre-mix insecticides Voliam flexi and Leverage are also labeled for cherry fruit fly control. Voliam flexi combines the two active ingredients, thiamethoxam and chlorantraniliprole, as a pre-mix formulated compound. Leverage combines the two active ingredients, imidacloprid and cyfluthrin, as a pre-mix formulated compound. Both have a rating of “good” for cherry fruit fly control in the 2009 Michigan Fruit Management Guide.
The use of SURROUND WP for fruit fly control is based on creating a protective barrier between the plant and the pest that 1) reduces host recognition of the pest, and 2) prevents adult oviposition (egg-laying). Because it is not toxic to adult flies like conventional contact poisons, complete coverage of the plant is critical. Multiple applications are typically needed to attain initial coverage; further sprays may be necessary to respond to wash-off from rain or excessive wind. Field trials indicate that when adequate coverage is maintained, excellent fruit protection can be achieved.
As a final management note, having fly populations infesting fruit that remain on the tree after harvest may be problematic because resident populations represent a source of infestation the following year. Growers with known high fly captures or fruit infestation post-harvest should consider applying an insecticide at this time to combat the resident populations and maintain them at such a low level that the threat of infestation prior to harvest is negligible. Our initial work on post-harvest cherry fruit fly treatments has indicated that the critical time to apply an insecticide is within the first week after harvest.
GREEN APPLE APHID ALERT
N.L. Rothwell, District Horticulturist, MSU-E
We have observed a high level of green apple aphid (Aphis pomi) infestations in orchards around the region. This European pest is seen in June and July and can reach high populations, particularly on water sprouts, young trees, and vigorously growing terminals. Like all aphids, they feed on leaf tissue with their piercing-sucking mouthparts, which results in curled foliage. If aphids are not controlled, the honeydew they excrete can create an environment for black fungus that will grow on the leaves and potentially the young fruits. Cool, wet conditions favor aphid development because this environment is unfavorable for aphid natural enemies.
The following products are all rated excellent for green aphid control: Provado, Actara, Assail, Calypso, Clutch, Beleaf, and Movento.
Insect and disease predictive information is available at:
http://www.enviroweather.msu.edu/home.asp
http://www.agweather.geo.msu.edu/agwx/forecasts/fcst.asp?fileid=fous46ktvc
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: 7-7-09
