This past week marked the beginning of the first of two flight periods of adult obliquebanded leafroller in Michigan. The first flight typically begins in mid-June and lasts about six weeks. The second flight takes place from early August to mid-September. Obliquebanded leafroller flight can be tracked through the season using pheromone-baited traps. Moth captures in pheromone traps also are used to initiate a degree day model, base 42°F. First sustained moth catch (catch on two successive dates) in pheromone traps is used as a biofix. Key events in the life history of obliquebanded leafroller can subsequently be predicted using the degree day model. For example, egg hatch begins around 400 degree days after biofix.

Although moth captures in pheromone traps provide valuable information to the scout and grower, they are not a reliable indicator of leafroller abundance or potential damage. Obliquebanded leafroller traps have a large active space. In other words, they potentially catch moths that originate from within the trapped orchard, neighboring or more distant orchards and native habitats. Thus, high moth catches may or may not indicate that the orchard being monitored has a leafroller problem. Very low catches of less than five per week strongly hint that obliquebanded leafroller is not a problem, but assessing larval activity is highly recommended to confirm this.

To get the information needed to make a sound management decision, a scout must look for leafroller larvae, or at least signs of their presence. Larvae are green with brown to black head capsules and are about 25 mm long when fully grown. Often, a scout will detect signs of leafroller activity rather than the actual larva. The name leafroller comes from the larva’s habit of rolling leaves to form a shelter. These feeding sites are most often found at the tips of growing shoots. Larvae also will use silk webbing to attach two leaves or a leaf and fruit together to form a shelter. The presence of webbing is a good clue that leafrollers are around.

Finding young larvae in the early spring is difficult, thus most growers take preventative measures at this time. If they were successful, fruit damage will be avoided and few larvae will survive and move to the shoot tips to feed. Scouting orchards for surviving larvae in growing terminals is the best way to judge whether intervention in the summer is likely to be needed as well. Orchards with less than 2% of the terminals infested should be monitored in the summer, but controls may not be warranted. Higher levels of shoot infestation are cause for concern and control measures are likely needed to prevent fruit injury. This investment of time could result in saving several sprays.

Degree day models are essential tools to be used in timing insecticide sprays. Optimal timing for summer sprays varies according to the life stage or stages targeted by the product of choice. For conventional insecticides, like organophosphates (OPs), pyrethroids and carbamates, the first sprays should be targeted between 400 and 450 GDD after biofix to control hatching larvae before they can damage fruit. Obliquebanded leafrollers are resistant to OPs in most apple growing regions of the state and are generally not the best option for control. Bt's are most effective when applied during warm weather conditions (daily highs in the 70's F). If Bt products are used, the latter timing (450 GDD) may be the better choice because they have a short residual, which must be present to control the larvae at the time and location they are actively feeding. If the first application is applied too early, it may take four or more sprays to keep active ingredient on the foliage throughout the long period of larval activity. Bt products are generally more effective with a lower tank pH. SpinTor has a similarly short residual (seven to ten days), but provides some contact efficacy, which will help kill larvae as they move to the actively growing terminals. SpinTor is also a good choice for leafroller control in cherry blocks where control with OPs and pyrethroids is failing to provide adequate protection. Proclaim, a new material (Avermectin class) has also shown very good activity against obliquebanded leafroller and requires ingestion by larvae.

In contrast, if Intrepid is used early, it should be targeted to cover egg masses around 350 GDD post biofix so that larvae will consume the chemical as they eat their eggshells upon emergence. Intrepid can also be used later to protect fruit against damage from older larval instars. Upon application, Intrepid has a long residual effect but should be reapplied where necessary on a 14-day interval to insure coverage of new terminal growth. Good, thorough coverage is key to leafroller control with materials requiring ingestion to be effective. The addition of an agricultural adjuvant to Intrepid 2-F is recommended to improve spray deposition.

Rimon acts by suppressing development within the egg, as well as larvae that consume it. Hatching of eggs laid by treated adults will also be inhibited. Eggs are particularly susceptible to these products when laid on top of sprayed residue, thus sprays should target 100 to 200 GDD after biofix. Similarly, Esteem applied at egg laying timing will also provide some control, though it is more typically used for the overwintering generation.

It should be noted that treating the summer generation of obliquebanded leafroller with SpinTor, Rimon or Proclaim would also provide some control of codling moth, Oriental fruit moth and spotted tentiform leafminer. Intrepid applied at the earlier summer obliquebanded leafroller timing would also assist in controlling codling moth and tufted apple budmoth. Esteem will provide control of San Jose scale crawlers and some added control of codling moth. Bt's can also be expected to control other leafrollers when applied in the summer for obliquebanded leafroller control.

As with many of our key apple pests, obliquebanded leafroller has a track record of developing resistance to insecticides. Currently, there are some good options for control of this pest. Practicing good resistance management should help conserve their efficacy. We encourage you to rotate materials with different modes of action. For example, if Rimon was the material of choice for control of overwintering larvae, opt for Proclaim, SpinTor or Intrepid if a summer treatment is warranted. During periods of warm weather, Bt is an excellent option and a good resistance management strategy.

Two primary diseases that affect cherries during the summer season are cherry leaf spot and brown rot. Powdery mildew can also affect tart cherries in a hot, dry year such as this one. Major constraints to an economically viable cherry production in Michigan include adequate control of these diseases.

Cherry leaf spot
The fungus Blumeriella jaapii (Rehm) causes cherry leaf spot in both tart and sweet cherries, although tart cherries show more susceptibility than sweets. Cherry leaf spot primarily infects leaves, but this disease ultimately decreases overall tree vigor and health. Purple lesions first show up on upper leaf surfaces, and eventually these spots turn brown. Wet weather causes whitish masses of conidia to grow on the undersides of the leaf in centers of the lesions. Often CLS appear as a one dimensional spot, surrounded by a light halo, on the top of the leaf, while the bottom-side lesion looks as if it is three-dimensional. A minimal number of lesions can cause the leaf to turn yellow and abscise. Trees severely defoliated prior to harvest produce light red fruit that have minimal soluble solids. These defoliated trees have difficulty forming buds and setting fruit for up to two years after severe infection; these trees are also less cold hardy and can die with low winter temperatures.

Chemical control
Cherry leaf spot control revolves primarily around fungicide applications as all cherry cultivars are susceptible to leaf spot. The first spray is usually applied as soon as the first leaves have unfolded. Sprays are often repeated on a 10- to 14-day (or 7-day alternate row) interval until harvest. There are many chemicals labeled for cherry leaf spot, but MSU research from 2003-04 has shown cherry leaf spot to be developing resistance to one class of fungicides, the sterol inhibitors (SI’s: Elite, Funginex, Indar, Nova, Orbit and Rubigan). This research suggests that Michigan growers need to shift from SI's to alternative chemistries for leaf spot control, which includes chlorothalonil (Bravo), strobilurins (Flint), strobilurin + Boscalid (Pristine), copper compounds, dodine, ziram and captan. Bravo is the chemical of choice prior to shuck split and post-harvest, as this chemistry provides good cherry leaf spot protection, and it does not have resistance potential. A tank mix of ziram and captan is an option for covers. Dodine is also an effective chemical where resistance has not yet occurred. Strobulirins work well, and Pristine is an excellent chemistry if powdery mildew is also a problem in the orchard. New research has also suggested that copper compounds are effective against cherry leaf spot in tart cherries only. When using an SI, always tank mix with another chemistry such as captan. For a complete table of recommended cherry leaf spot control strategies, please see the May 3, 2005, Fruit CAT Alert.

Brown rot
Warm, wet or humid weather is conducive to brown rot (Monillinia fruticola) development, and brown rot is a major disease of stone fruits. Sweet cherries are particularly susceptible. Once the fruit begins ripening and changing color, it becomes more susceptible. This pathogen can gain easy access to fruit when any type of injury (insect damage, hail injury, bird pecks, bruised and/or cracked fruit, etc.) is present. Once the pathogen becomes established, soft brown spots appear on the fruit. These spots rapidly expand into lesions covered with powdery masses of creamy-tan colored conidia. Under favorable conditions, the entire fruit may rot within 48 hours. Eventually fruit that remains on the tree dries out; these fruits are often referred to as “mummies,” and they become source for future infections.

Disease management
As it is true with any disease, reducing inoculum level will lower disease pressure. Control of blossom infection is important to minimize disease inoculum for fruit protection. Fruit injury should be minimized to reduce the fruit’s susceptibility to M. fruticoloa. Insect damage to the fruit should also be curtailed to decrease disease outbreaks.

Chemical control
There are several good fungicides that provide adequate control for brown rot disease. Protectants (captan, Wettable Sulfur) may be an adequate option in low-pressure situations. Materials from this group must be applied prior to the expected wetting event. Sterol-inhibitors (Elite, Indar, Orbit) will provide excellent control of fruit brown rot, but these materials should be used judiciously as resistance has been reported with these products in cherry leaf spot disease. SI products are best applied before the onset of the infection, but some of these fungicides have a limited back action of 24 to 36 hours (Indar, Orbit). SI are again best applied in a tank mix with a protectant such as captan. Strobilurins (Flint, Pristine) adequately control brown rot, and they are currently an option for fungicide resistance management. They must be applied prior to the wetting event since there are no available data as to their kick-back action. Other options are available for brown rot blossom blight control such as Rovral and Bravo that cannot be used for summer control.

Powdery mildew
Tart cherries are particularly susceptible to powdery mildew (Podosphaera clandestina) during hot, dry weather. When mildew first infects young leaves, it looks like a whitish felt-like patch (mycelium) on the bottom of the leaf. The top of the leaf usually boasts a wrinkle, and there is a halo-like appearance where the mycelium is growing on the underside of the leaf. These powdery lesions can spread quickly and can soon cover the entire leaf. Eventually, small brown to black globular bodies develop in the mycelium. Fungal spores are spread from leaf to leaf when temperatures hit 68°F. Powdery mildew takes hold of an orchard when temperatures are high and moisture is generally low but spiked with times of high humidity. Mildew can spread rapidly throughout an orchard if inoculum levels are high. Heavily infected terminal leaves tend to shatter during mechanical harvesting.

Disease management
Increasing air flow in the orchard is the best cultural control for powdery mildew. Pruning trees to improve air circulation will create a less optimal environment for powdery mildew development.

Chemical control
Powdery mildew is often controlled with fungicide applications. Since this disease is most often a problem in hot and dry years, every season may not require a powdery mildew fungicide application. However, powdery mildew is important to control at the onset of the problem as this disease progresses rapidly and can overtake the orchard in a short amount of time. The disease is best controlled during the first cover to the pre-harvest period. Flint and Pristine are both excellent. Nova, Rubigan and Elite (SI’s) are all fair to good, but their use should be minimized due to resistance concerns. Sulfur provides some control.

Two Cherry Variety Showcases will be held this summer in Michigan. International Plant Management (IPM), Summit Tree Sales and MSU Extension are jointly sponsoring both events.

• Variety displays and discussions
• Haygrove Tunnels over an established orchard
• Orchard tours
• Dwarfing cherry information
• Join us for lunch!

Speakers include Greg Lang (MSU), Andy Crittenden (Haygrove), Wally Heuser (IPM), Bill Shane (MSU), Phil Schwallier (MSU) and Amy Iezzoni (MSU)

Haygrove Tunnels is also a cosponsor of this session.

The program will include:

• Fresh and processing variety displays of cherries collected from several test plantings in Michigan and New York.
• Introducing two new processing sweet cherry varieties from the NY breeding program.
• Discussions of varieties with Jim Nugent (MSU), Greg Lang (MSU), Wally Heuser (IPM), Susan Brown (Cornell University) and Amy Iezzoni (MSU).
• Join us for a barbeque dinner!

If you have questions contact Summit Sales at 800-424-2765. RSVP is not required, but would be appreciated by Summit Sales.

A good prediction of peach harvest dates helps growers, shippers, marketers and buyers plan their season. For Michigan, the start of significant peach volume is with the harvest of Red Haven, and so a good predictor for this variety would be valuable to many.

To this end, I have collected dates for the onset of significant commercial Red Haven harvests in Berrien County since 1995 and have correlated this with various combinations of degree day models using weather data from the Southwest Michigan Research and Extension Center. The following is my first stab at a degree day model for Red Haven harvest onset. This is very preliminary, and it is unclear how to use these results in other locations, but these results should be of value until a better model is devised. (view image)

The Red Haven harvest onset model uses a degree day accumulation starting January 1 through June 3. Regression analysis was used to predict harvest onset. The resulting predictive equation is D = -0.0428x + 236.78, where x is the cumulative GDD50 from January 1 through June 3 and D = the day of year (e.g. January 1 = 1 and December 31 = 365 in a non leap year.

For 2006, the GDD50 through June 3 was 524. Plugging this into the formula, the estimated start of Red Haven harvest is 214.3, which is August 2. As can be seen, the trend line is not a perfect fit to the data. The observed harvest date is often three to five days from the predictor line. There are other factors such as temperatures after early June, rainfall and crop load that will affect peach maturity, and these factors are not considered in this current model. However, this model will provide a rough guide to the start of Red Haven season.

Strawberry beds that are to be carried over for another harvest season need to be renovated. Deciding whether to renovate or remove a bed differs with each grower’s circumstances, such as market demand, land availability and production costs. As strawberry fields age, yields and berry size decline, while weeds and some diseases increase. Growers with high market demand but limited available acreage may need to retain beds longer. In the end, an educated decision requires thorough knowledge of your production costs and net returns over the preceding seasons. If you decide to renovate, start as soon as harvest is over. The earlier runner plants develop, the higher they yield the following year, so delaying renovation costs yield. Also keep in mind that renovated beds need abundant water in July and August. To renovate, follow these steps:

Mowing off the leaves just above crown height if the plants are healthy. If the plants are stressed by drought or root diseases, do not mow the leaves; weak plants have difficulty developing new ones. Also do not mow the leaves if renovation is delayed for more than a few weeks after the end of harvest.

Narrow the rows to 8 to 10 inches by cultivating with a rototiller or disk. Rototillers with tines removed above the row work very well because they toss some soil on top of remaining plants, which encourages additional rooting. However, more than an inch may smother the plants.

Some growers have had success narrowing rows by treating the row middles with directed or shielded sprays of the herbicide Gramoxone (paraquat). Gramoxone is a contact weed killer that is not mobile in plants, so it only affects treated tissues. This method effectively narrows the plant row, and does not expose new weed seeds by disturbing the soil. One potential problem with this approach is that it does not provide a loosely tilled soil which is best for rooting of runner plants. It also does not throw soil back over crowns.

Herbicides
Renovation is also a useful time to treat beds with amine forms of 2,4-D (Amine, Formula 40) for broadleaf weed control. Strawberry plants tolerate 2,4-D after harvest because they are not actively growing. If broadleaf weeds are a problem, apply 2,4-D a few days before mowing. This herbicide must be absorbed by the weed leaves to be effective so don’t mow off the weed leaves before applying 2,4-D. Sinbar can also be applied at renovation for preemergent weed control. Apply 3-6 oz of Sinbar 80W per acre, using the lowest rates on sandy ground or weaker plant stands. Mow plants first so that Sinbar is applied uniformly to the soil. Irrigate to rinse the herbicide into the soil. Michigan has a Section 18 label for the preemergent herbicide Spartan. Spartan is effective on common groundsel, field pansy, mayweed, white campion (white cockle) and pigweeds. Apply 4 to 8 oz Spartan 4F per acre, after plants have been mowed.

Fertilizing
The last step in renovation is to fertilize. On heavier loamy soils, apply enough fertilizer to supply 50 lb N per acre. On sandy soils, apply 30 to 40 lb N at renovation and again in early August. Do not neglect irrigation on renovated beds.

Regional reports
1 -- Southwest
Mark Longstroth
Bill Shane

General insect activity
Potato leafhoppers are becoming more abundant. Japanese beetles are emerging. Redbanded leafrollers are flying again. Tarnished plant bug activity is declining. Rose chafers are out but not in large numbers. Plum curculio activity is light. You can monitor the GDD model for some pests at the Enviro-weather site.

Sweet cherry harvest has begun. Birds have been a big problem this year, and growers have lost a great deal of fruit. Fungicides to control brown rot should be applied. Cherry fruit fly traps should be out, especially where sweet and tart cherry varieties are grown together.

Tart cherry growers will be applying Ethrel this week. Growers need to protect against cherry leaf spot. Cherry leaf spot has been reported in orchards where DMI fungicides Indar were used, indicating that resistance was the issue and not poor application timing. Cherry fruit fly are seldom a serious problem in southwest Michigan in areas where only tarts are grown. The flies seem to emerge late at about harvest time and develop in fruit left on the trees.

In plums the crop looks decent. Shoot growth continues and growers need to protect against black knot. White apple leafhoppers are causing stippling of the leaves.

Apple fruit drop continues. We have had 248 hours of leaf wetness since petal fall so sooty blotch and flyspeck symptoms should show up in unsprayed orchards soon. Growers need to maintain scab protection if they find leaf lesions in their orchards. Growers should continue to protect against powdery mildew in problem orchards. Fire blight symptoms and bacterial ooze are not common but some orchards are showing more symptoms. Trauma blight could be a problem if we get severe weather in these orchards with oozing shoots. Oriental fruit moth is between generations. Codling moth trap counts are down but egg hatch continues. Many growers are applying the second cover spray. Obliquebanded leafroller are being caught in the area. Biofix for obliquebanded leafroller occurred last week on Monday June 12 at 1150 GDD42. European red mites eggs are being found. Apple maggot traps should be out.

In grapes, fruit clusters on primary shoots are at shatter and clusters on secondary shoots are blooming. Rose chafers are feeding in some vineyards. Post bloom sprays are due. Grape berry moth numbers are high. Grape flea beetle larvae are feeding on the leaves in unsprayed vineyards. Some growers are still deciding if they will harvest. Phomopsis leaf lesions are common in most plantings.

Strawberry harvest will probably end at the end of the week. Fruit has ripened rapidly due to the heat last week and fruit size is falling off. Fruit quality has been good. Irrigation is important to maintain good fruit size. We expect renovation to begin early next week.

Raspberry harvest will begin soon. Growers should be scouting for Japanese beetles. Pre harvest fungicide and insecticide sprays should go on soon.

2 -- Southeast
Bob Tritten

Our soils remain dry to extremely dry. It seems as if areas from Ann Arbor to the north have not had the benefit of rain events that have occurred earlier in June. Soil conditions in the Thumb are extremely dry. Most growers have now “fired up” irrigation systems.

Insect activity seems to be in a bit of a lull with the exception of Oriental fruit moth trap catches, which are starting to rise in the last few days. Some farms have high codling moth trap catches. Codling moth trap catches remain low, however I’ve seen trap catches in the range of 70 to 90 moths per trap over the last week. This higher flight may have been the end of the first generation or what entomologists now are referring to the “B” peak. For the most part I’ve seen low numbers of codling moth trap catches in most mating disruption blocks and where virus is being used. As mentioned earlier, Oriental fruit moth trap catches are beginning to rise. This is the start of second generation flight. Obliquebanded leafroller trap catches also were on the rise last week with many growers biofixing midweek or so. While I am still seeing plum curculio in trees, I have not seen any fresh damage or egg laying activity over the last week. Woolly apple aphids seem to be moving from the branch tips towards the trunks with pretty good numbers at some farms. Green apple aphid numbers continue to build, which can help to bring in more predators. Dogwood borer adults are now flying, and the larva frass is plainly visible in burr knots. Potato leaf hopper are starting to curl some foliage, however their numbers are low. San Jose scale adults are being caught in traps.

Apple scab lesions continue to show up on foliage with a lesser amount on fruit. We had a rain event late afternoon on June 18 at both of our apple scab spore monitoring sites. We are no longer catching apple scab spores. Therefore, I am calling an end to primary apple scab season. I feel our season ended a bit ago, however we do not have any rain events at these sites to make this determination. I’m not seeing any increase in fire blight shoot strikes over the last week’s report. Powdery mildew infections continue to show up in more blocks.

Pears continue to grow well with most being around 1.25 inches. I am encouraging growers to remove suckers from the inside of pears at this time to help break the pear psylla cycle, as I continue to see high amounts in some blocks.

Peaches continue to size quite nicely with Red Haven being 1.25 to 1.5 inches. Peach thinning continues. There is a tremendous crop. Peach leaf curl symptoms continue to show up in a few blocks, and bacterial spot infected foliage and fruit continues to be seen in higher amounts. I’m also seeing some minor amounts of peach scab.

Sweet cherry harvest started on Monday at a few farms and will begin late this week or this weekend. This early beginning of harvest is about a week to 10 days ahead of normal. Cherry fruit fly was caught for the first catch of the season late last week. Black cherry fruit fly was caught on traps for the first time this morning (June 20). Control measures for both are now recommended. Birds have been a tremendous problem in sweet cherries over the last week. Growers need to make sure that they have all of their bird scare techniques in place immediately. While this first picking appears to be good size, it appears that many of the later harvested cherries will be lacking in size. Cherries harvested right now are 20 to 23 mm.

Tart Cherries have sized well over the last week with most being 17 to 19 mm. Fruit is now reddening quite nicely.

Plums continue to drop, resulting in a below average crop. Plum size is currently 20 to 22 mm. As was mentioned in the apple report, I’m not seeing any new plum curculio sting.

Raspberries have continued to grow very nicely. I expect harvest on some of the early maturing summer red raspberries in a few weeks. There are no major pest problems to report.

Blueberries continue to size quite nicely with most being in the 9 to 12 mm range and some at 14 mm. Some of these early fruit are just beginning to show some color change from green to blue.

Grapes are in bloom with a good amount of new growth this season.

3 -- Grand Rapids Area
Phil Schwallier
Amy Irish Brown
Carlos Garcia-Salazar

Very little primary scab can be found and this is only in highly susceptible varieties.

A regional biofix for codling moth was set for May 10 and we’ve accumulated 525 GDD50 since then. In general, trap numbers have dropped off from the previous week, but there are a few blocks with very high trap numbers yet. We are at peak egg hatch for first generation codling moth, so controls will be critical over the next 7 to 10 days. Larvae are active and can be found in fruit in non-sprayed trees.

A regional biofix was set for obliquebanded leafroller for June 12. We’ve accumulated 200 GDD42 since then indicating that early egg hatch is probably a week away.

No new plum curculio egg laying scars have been found in apples for the past week. We are probably past the peak period for damage in apples, but could see additional activity in stone fruits over the next week. Monitor peaches and cherries closely.

European Red Mite populations continue to build in some blocks with all stages of red mites being found. Rosy apple aphids can still be found. Green apple aphids are building. Predators are more common in aphid colonies as well. White apple leafhopper nymphs continue to be found in normal numbers. First reports of adults are being seen. We should be at peak egg hatch now. Potato leafhopper adults and new nymphs are also present.

A regional biofix for Oriental fruit moth was set on May 1 (297 GDD45). GDD45 since biofix = 791. First generation adult trap numbers have declined, and we should be getting towards the end of flight has declined, but second generation flight should begin at anytime. Lures should be changed soon. Dogwood borer trap numbers are low. Trunk applications should be timed for the around July 4.

Regarding insect pest problems, the cherry fruit worm continues emerging in most fields. Although, there has been a decline in the number of moths trapped in pheromone traps fresh ovipositions have been observed during the past week. Similarly, adult cranberry fruit worm continues emerging and during the past days egg-laying has been abundant. So far, most of the fruit damage observed has been caused by the cherry fruit worm which started two weeks earlier than the cranberry fruit worm. At this time, we are finding first and second instar cherry fruit worm larvae. Most cranberry fruit worm are first instar larvae.

4 -- West Central
Mira Danilovich

Rain on Sunday (June 18) was an infection-producing event. No spores have been found on the rods ending the scabprimary. There are some scab lesions in commercial blocks scattered throughout the district. Fire blightstrikes are more evident mainly in blocks with known history of a problem. There are a few more reports of Nectria twig blight symptoms in Rome and Spy blocks. Powdery mildew is scattered throughout the area. High humidity continues to favor disease development. Insect activity seems to have dropped off. Codling moth count continues to decline mainly as a result of the spray applications targeting the first generation control.

Obliquebanded leaf roller numbers are beginning to pick up. The biofix is set June 17 at 1065 GDD42. Peak flight is expected around 1300 GDD42. Plum and apple curculio stings have been found on the apples. White apple leafhoppers and potato leafhoppers are present and already doing significant damage. There is some damage done by the spotted tentiform leafminers. Aphids continue to be a major pest. European red mite count is on a rise. Overall numbers are still low.

Sweet cherries are gaining in size and color. Some of the numbered NY varieties are already ripe. Early ripening varieties will be ready for harvest by this weekend. You may expect some damage from rain in the early varieties that have frost scars on the fruit. That scar has lost elasticity and will not expand but may and will crack depending on the water “in-flow” pressure. At any rate, now that the cherries are maturing, there is a need to step up the brown rot control . Many growers have already applied ethrel on sweets anticipating an earlier harvest. Tart cherries are coloring up and looking better with each day.

Peaches are exceeding an inch in diameter. The crop load is very good. Thinning is underway.

Bacterial leaf spot and bacterial canker are found quite readily in all stone fruit. Powdery mildew is being found in many blocks. A few incidences of peach mildew and scab have been reported. Present weather conditions are favoring disease development. Peach leaf curl is present in fare amount throughout the area. This morning was reported that the first cherry fruit fly was caught June 19 in Manistee County, Bear lake area and in Oceana County, Elbridge area. No reports of any catches in Mason County yet, but I would expect it any day now. Historically, we would find it only a day after it had been reported in Oceana County. Control application should go on in about 7 to 10 days from the reported cherry fruit fly emergence. American plum borer trap catch has zeroed out. Lesser peachtree borer numbers have dropped 50 percent since last week. Greater peachtree borer trap catches have tripled since last week. Scouts are reporting finding rose chafers . Generally, it appears that their numbers are lower than previous years. There is still damage done by plum curculio . Green peach aphids are present in very high numbers. There is surprisingly high numbers of predators in the aphid colonies as well. Scouts are reporting finding peaches with evidence of tarnished plant bug feeding. Oriental fruit moth flagging has been evident in some peach blocks throughout the area. No second-generation Oriental fruit moth flight reported yet.

5 -- Northwest
Nikki Rothwell
Jim Nugent
Jim Bardenhagen
Duke Elsner

Cherry leaf spot symptoms are evident in many tart cherry blocks, and the Sunday rain resulted in moderate to high cherry leaf spot infection all across northwest Michigan. At the end of last week, we were still observing active plum curculio. Plum curculio collected in northwest Michigan last week and dissected still contained many eggs yet to be laid. American plum borer and lesser peach tree borer counts are down, while greater peach tree borer numbers are constant at an average of 7.7 adults/trap at the NWMHRS. Obliquebanded leaf roller adults are being trapped in cherry at significantly higher numbers than in apple blocks. In the past two weeks, we have caught a total of 25 cherry fruit fly adults in our unsprayed entomology block.

As potato leaf hopper numbers increase, growers should be monitoring plums for potential damage.

A fast zonal (west to east) jet stream pattern across the northern United States will lead to relatively active weather for the majority of the next few days, followed by a fair, cooler and drier pattern for the upcoming weekend. The frontal boundary that moved through the state last Sunday will approach the state from the south as a warm front by Wednesday and is expected to temporarily stall over southern sections of the state through Thursday. Combined with a strong upper air disturbance approaching from the northwest and large amounts of Gulf of Mexico moisture from the south, showers and thunderstorms are a good bet over most of the state beginning late Tuesday and continuing through Wednesday. Depending on how much sunshine is available Wednesday, some severe thunderstorms are possible with damaging high winds being the primary threat. Chances for severe weather and the likelihood of rainfall will be greatest across southern sections of the state decreasing northward. Showers and a few thunderstorms will be possible once again Thursday, primarily across southern sections of the state. Fair and dry weather is expected to develop by Friday statewide and continue through the majority of the upcoming weekend as high pressure moves into the region. Rainfall totals during the next five days are projected to remain generally within the 0.25- to 0.5-inch category with some 1.0 inch totals possible across southern sections of the state.

Temperatures will fall from high temperatures Wednesday ranging from the upper 70s far north to the low and mid-80s south back to the 70s to near 80 by Friday and continue through the weekend. Low temperatures will generally range from the 50s north to the 60s south Through Thursday morning, falling back to the upper 40s to 50s during the weekend. Overall temperatures during the next five days are forecast to generally average 2 to 4 degrees below the normals. Following a dry weekend, rainfall will be possible once again by next Monday as a weather system approaches from the west.

Medium range forecast guidance strongly suggests the establishment of a large upper air ridge across the southwestern United States with a troughing feature across the east, which would keep Michigan under the general influence of northwesterly flow aloft in a somewhat benign weather pattern.

The 6-10 day and 8-14 day outlooks (covering June 25-29 and June 27 through July 3) are very similar, calling for near normal temperatures statewide and for precipitation to range from near normal levels across the southeastern one-half of the state to below normal levels across the northwest. Given good agreement among the various forecasting tools, forecaster confidence in these outlooks is considered greater than normal for the time of year.