This past year we started trying a technique in tree training that originated in Europe called "Debudding." The technique (Tobias Vogel, Germany), which is used principally on sweet cherries, calls for the removal of buds in the upper region of leaders. Buds closest to the terminal portion of a leader harbor and synthesize more auxin (plant growth hormone) than buds lower in hierarchy on the leader. The hormone flows down from these buds (and small developing leaves), which inhibit the growth in the lower buds. Secondly, branches that develop from the buds in the terminal area are more vigorous and possess a narrow angled crotch. This characteristic is more pronounced for laterals sprouting from the uppermost buds. Often in sweet cherry, buds below the one closest to the terminal never break and you get a region of blind wood.

The technique of debudding is applied soon after growth begins, when the grower is secure in knowing which buds survived the winter (half inch new growth). The new technique described here for sweet cherries applies to leaders when headed or left intact. Heading is not needed on leaders that produced less than 20 inches of growth in the previous season. Most of the sweet cherry varieties we grow in Michigan, which produce more than 20 inches of leader growth in a season, are typically apically dominant and require heading of the leader in the first few years to force lateral branching.

At a half inch of bud growth, leave the upper-most two to three buds alone and remove the first seven to eight buds below them (three to four in newly planted trees). For leaders with long growth (20 inches or greater), head the leader so that one-half to two-thirds of the leader growth from last season remains. In cases where the leader made 36 inches of growth or greater, consider removing more than seven to eight buds (first 12 inches of leader growth of buds below the heading cut).

If any of these buds are allowed to develop, growers will be confronted with the challenge of physically spreading the laterals. For these upper laterals, this can be a constant challenge, adding to labor costs in developing sweet cherry trees. Secondly, these laterals never seem to take on a reproductive characteristic, which is critical in developing precocious trees on dwarfing cherry rootstocks. Even when they are trained during the summer, they remain dominant and have a tendency to compete with leader development. Unfortunately, if allowed to remain through the season, the grower is required to prune these branches in the winter, attracting bacterial canker infection. Therefore, debudding can help develop better-angled branches and prevent the making of pruning cuts near the leader.

Once the buds start to develop, the next operation involves the spreading of branches to form 90° crotch angles. Thus far, there is only one way and with only one instrument that this can safely and effectively be accomplished. As in the previous article that describes the SS for cherry, a plastic clothespin is placed on the leader (perpendicular and clasped to the leader) and obstructs the development of young branches when they are about 3 to 4 inches in length (the length of a clothespin). If this is not done and the grower waits until the branches are 10 to 12 inches long (which is ok in apples), the crotch angle is lignified and formed. Then when you attempt to spread the succulent branch, many of the branches break immediately or by the next day and you are left with broken cherry branches. Secondly, spreading the branches to 90° from the start avoids "bark inclusion" on the upper side of branch attachment to the leader. When this occurs, a mechanical pinching of the meristematic tissue occurs, which inhibits vascular function and causes weakness. Eventually, canker and cold injury occurs at these points and the branch is ultimately destroyed. Therefore, it is critical that a clothespin is used from the beginning. We have found that not just any clothespin works for sweet cherry. Wooden pins used in apples have too narrow a jaw opening and slip out of position on sweet cherry branches. Other plastic pins don't last or don't have a wide enough jaw. In North America, the only product I have found that works is one distributed by Seymour Housewares Corp., Seymour, IN. They handle several products and specifically the one that works is called the "Super Grip" Clothespin (model # 12-123-33). It is sold off the shelf through Meijer's stores in Michigan at $1.80 for 24 count packages and $2.99 for 36 count packages. However, a distributor LDK Sales, 1469 Kings Way, Highland, MI 48356 (248-887-3956 voice and 248-889-2609 fax) can take orders and deliver the same product to growers at a price of $.96 per 24 count package. Not only does this pin have the largest jaw and best design to fit a branch snuggly, it also has a wide surface area and is most effective in obstructing branch development.

Once the branch crotch is formed and branches are 10 to 12 inches long, we recommend the tying down of branches with elastic bands or cotton string to keep them directed in a horizontal angle. Clipping wooden clothespins (multiple) to the ends of branches can also be effective (wooden pins are cheaper and heavier in weight than plastic pins).

If you must remove a two-year-old branch or older in the wintertime that is unwanted because of poor placement or undesirable crotch angle, try not to make the cut near the leader. Instead, the technique developed by Fritz Zahn, calls for cutting the branch to a length of about 6 to 10 inches long (leaving a stub). The branch is then completely removed in the mid- to late summer, even after harvest when it is hot and dry. Making the cut at this time lessens the potential for bacterial canker infection on the leader. Some would ask, why make the cut at all during the winter? The problem is that the branch and its vigor may need to be suppressed as soon as possible to prevent its imposition and competiveness on the rest of the tree. This technique was developed in Northern Germany, where bacterial canker is even more serious than in Michigan.

If the grower will follow the procedure of training branches during the summer of the first four years as outlined here, stubbing cuts should not have to be made. This will also help you avoid any and all pruning cuts made on dormant wood. The only cut that should have to be made is for those varieties that require leader heading to force lateral branch development (most varieties grown in Michigan). The dwarf sweet cherry trees being planted today stand to make growers a premium in returns for there fruit, especially for fresh and pick your own markets. Tree cost and investment and revenue generation is great per acre. From that perspective, it is worth it to a grower to put the time and effort into proper training to maximize the full economic gain and avoid the scourge of sweet cherry growing in Michigan, bacterial canker.

The whitemarked tussock moth (Orgyia leucostigma) is a sporadic pest of blueberries in Michigan, but is distributed throughout eastern North America. Larvae also feed on hardwood and ornamental trees, and can be found in native habitats surrounding blueberry fields. Growers sometimes need to manage this insect if larvae become present in the field during the pre-harvest and harvest periods.

Larvae grow to 1.5 inches long (Figure 1), changing from a light brown color to multicolored as they grow. Full-grown larvae have a bright red head with a yellowish body, a pair of upright pencil tufts of black hairs on the prothorax, and four white to yellowish brushlike tufts of hairs on the top of the body toward the head. After the first instar, larvae have a conspicuous red dot on segments six and seven.

Larvae pupate on leaves inside a pupal case lined with their long hairs (Figure 2), and moths later emerge to find a mate. The adult male moth is gray brown, with darker wavy bands and a white spot. The female is wingless and whitish gray. After emergence from the cocoon, she mates and lays eggs in a mass on her cocoon. Eggs overwinter in leaves, which may then drop to the ground under the bush or stay on the wood through the winter. Overwintering eggs hatch in early June, and over 100 larvae can emerge from one eggmass. Larvae feed throughout June and July, becoming large larvae during harvest season. One generation per year is typical under Michigan climatic conditions.

Young larvae chew holes in leaves when small (Figure 1), but as they grow entire leaves can be removed by larvae that begin feeding at the leaf margins. When large numbers of larvae are present, sections of a bush can be completely defoliated. However, larvae are primarily a pest due to their presence around harvest time when their allergenic hairs irritate the skin of fruit pickers. Presence of larvae in mechanically harvested fruit is also undesirable. Scouting of fields for larvae in mid-June can provide information on whether larvae require control before re-entry and pre-harvest interval restrictions limit grower's options for removing whitemarked tussock moth from an infested field.

Parasites, predators, microbial diseases, starvation, and unfavorable weather normally bring epidemics under control in natural systems. In commercial blueberry production, whitemarked tussock moth can occur in very high numbers in a restricted area, and control of larvae may be required before fruit are harvested if a field is infested.

Regular scouting of bushes for eggmasses and particularly for larvae in June and July can provide an early warning of a tussock moth infestation. Past history of larvae in harvested fruit is a good indication of the need to be alert for their presence in the following year.

Larvae are often found on the underside of leaves, so turning over leaves with feeding damage can help locate larvae. Beware of the allergenic hairs and approach with caution! Postbloom insecticides for other moth larvae are likely to also control tussock moth.

A recent test of insecticides was conducted by the Small Fruit Entomology Lab at MSU to compare their control of tussock moth. Untreated blueberry leaves were dipped in field rates of Sevin XLR (2 qts/acre), Guthion 50 WP (1.5 lb/acre), and Confirm 2F (16 oz/acre) and left to dry in a fume hood for one hour. Third instar tussock moth larvae were then placed on the foliage with these different treatments. All insecticides provided 100 percent control of the larvae, though they took different times to act (Figure 3). Of the broad-spectrum insecticides, Sevin had the fastest effect with Guthion close behind, killing all of the larvae within four to five days of treatment. Other broad-spectrum insecticides that may be applied for cranberry fruitworm or for aphids at this timing are also likely to control tussock moth. Confirm is a selective insecticide that disrupts molting of moth larvae. This treatment took eight days to kill all of the larvae, but there was a similar low level of feeding in all of the insecticide treatments, because larvae eating Confirm-treated leaves soon stopped feeding.

Bloom time grape insects

Emergency Section 18 labels have been granted by the Environmental Protection Agency for use of two formulations of imidacloprid against Japanese beetle in Michigan blueberries. The labels for Provado 1.6F and Admire 2F cover all counties of Michigan, and allow application of these two products until September 30, 2002. This article provides some recommendations for blueberry growers to achieve maximum effect from applications of these products.

Admire is the soil-applied formulation of imidacloprid, which targets the young larvae hatching from eggs that will be laid this summer. Application this year is therefore a preventative treatment to reduce beetle infestation in 2003. It will have minimal effect on beetle emergence this year because most grubs are fully grown by late June and are not at a susceptible stage.

Admire should be applied to grassy regions of blueberry fields (row middles, drive lanes, headlands) by the start of Japanese beetle egglaying (typically by July 4) for it to be present in the soil when larvae hatch. Applications need to be watered in with 0.5 to 1 inch of applied water or rain for it to move through the thatch layer and be present in the root zone where larvae start feeding; application must be made at least seven days before harvest. Research trials on Japanese beetle grubs in Michigan blueberry soils conducted in 2002 showed similar activity of the 16 oz and the 25 oz rates (over 80 percent reduction in grub density) when applied in early August. Over 90 percent activity is expected with application made before egglaying starts. Imidacloprid is quite stable in the soil, and so only one application is required per year, providing control of larvae throughout the two to three month egg-hatching period.

The greatest density of Japanese beetle grubs have generally been found in permanent sod around blueberry fields. An economical use of Admire might be to apply it only to headlands and drive lanes where beetle egglaying and grub densities are highest. Using this approach on a 20-acre field should significantly reduce the amount of beetle immigration in 2003 from an application in 2002, spraying to less than one acre of total land (the headlands and drive lanes).

Provado at 8 oz per acre provides initial lethal activity against adult Japanese beetle. As the compound is absorbed into the leaves, lethal activity declines and sublethal affects, such a reduced feeding and paralysis continue for seven to teh days. This product has a three-day pre-harvest interval. Only two applications of Provado at 8 oz per acre are allowed per season. This product requires thorough coverage for optimal control, because beetles can move to untreated regions of bushes if residues are not throughout the bush.

Regardless of the formulation used, a maximum of 0.5 lb active ingredient is allowed. This means that if Admire was applied to a field at the 16 oz rate (0.25 lb active ingredient), then two applications of Provado at 8 oz could still be made. However, if the 25 oz rate of Admire was used, then only one Provado application could be made.

Environmental safety considerations outlined on the labels should be closely followed, particularly near bodies of water. As always, label directions should be carefully followed when using these products, and the label must be in the possession of growers applying these products. Copies can be acquired from suppliers, or the Emergency Labels can be downloaded by clicking these links:

A new fungicide, Switch 62.5WG (cyprodinil + fludioxinil), has been labeled for use on strawberries. It is formulated as a water-dispersible granule. This fungicide has a unique chemistry and is partially systemic. It is considered a reduced-risk material with strong activity against Botrytis gray mold. Switch also suppresses strawberry anthracnose. In various fungicide efficacy trials in strawberries and other small fruit crops in Michigan, Switch showed good activity against Botrytis and suppressed foliar diseases.

For strawberries, the application rate is 11-14 oz/acre. Begin applications at or before bloom and continue on a seven to ten day interval. Because of its favorable toxicological profile, the pre-harvest interval is zero days. The maximum amount of product allowed per year is 56 oz. Even though the risk of resistance development is relatively low because of the two different ingredients, alternating with other registered fungicides such as Elevate or Captan is recommended. The new label for Switch expands the toolbox for fungicide resistance management. Do not apply Switch through any type of irrigation system.

Bushberries (blueberries, gooseberries, currants and huckleberries) and caneberries (red and black raspberries, blackberries and loganberries) have been added to the Elevate 50 WDG fungicide label. Elevate was already labeled for control of Botrytis cinerea in grapes, strawberries, and pistachios; and Monilinia diseases in almonds and stone fruit. The active ingredient in Elevate is fenhexamid, which has a unique chemistry. Elevate is a protectant, reduced-risk fungicide, formulated as a wettable dry granule which makes it easy to use. It provides good control of Botrytis gray mold and in field trials in blueberries also suppressed Phomopsis twig blight and mummy berry.

The application rate of Elevate is 1.5 lbs of product per acre. Begin applications at 10 percent bloom and continue through harvest on a seven-day schedule or when conditions favor disease development. Elevate has a zero-day PHI. Do not apply more than 6 lbs of product per acre per season and avoid making more than two consecutive applications before switching to a fungicide with a different mode of action. Elevate should be alternated or tank-mixed with other registered fungicides, such as Captan, to lower the risk of resistance development. Apply Elevate using ground equipment only and do not apply through any type of irrigation system. Do not replant food crops other than those for which the product is labeled within 30 days following the last application.

Blueberry bushes in many Michigan fields have not leafed out normally this season. In severe instances, canes with a large load of developing berries are nearly devoid of leaves. Often the oldest canes are most affected and younger canes may leaf out normally. This situation has been observed in other years, but normally just on heavy setting varieties such as Bluecrop. Although the cause(s) of this is not clear, a number of possibilities have been suggested.

Carlos Garcia, Ottawa County Small Fruit Agent, observes that the symptoms in his area are generally confined to Bluecrop and are most acute in frost-damaged fields. He observed damage to vegetative growth following three freeze events in April and early May. In one Bluecrop field, bushes in the lowest areas had no leaves, whereas those on higher (less frosty) areas showed much less injury.

Dave Trinka with MBG-Marketing pointed out that cold weather could potentially affect leaf and shoot development without killing the growing point. Perhaps developing leaves were injured enough to slow or stop growth. Cold soils through May could have contributed to this. A delay in vegetative growth would result in more competition between shoots and developing fruit for carbohydrates. The fruit load in many fields is very large, so competition may also be involved.

Jim Hancock, Horticulture, pointed out another anomaly about this year that may be involved. Across several farms from Berrien to Muskegon Counties, bushes produced 30 to 50 percent more flower buds this year than normal. If a higher percentage of nodes develop into flower buds, fewer are left to produce shoots. Older canes tend to produce shorter shoots with fewer nodes, so more flower bud initiation can result in considerably fewer shoots. Conditions that favor flower bud initiation are adequate rain and an extended, warm fall. The high flower bud set likely contributed to the current situation.

These symptoms appear to be the combined result of cold weather and abundant flower buds. Trimming off some fruiting laterals on affected canes may encourage vegetative growth and maturation of the remaining fruit, but this requires considerable time. Additional fertilizer is unlikely to help the situation. Mark Longstroth, District Fruit Agent, indicated that vegetative growth has progressed recently in some fields, and bushes are expected to leaf out with the return of warmer weather.

Last week was cooler and dry. Temperatures slowly fell through the 70's into the 60's by the weekend then temperatures to 80's on Monday (June 17). Scattered thunderstorms dropped little rain. Hail was reported in Berrien County on Saturday. Warm temperatures helped dry the soil but soil moisture is still adequate and soil temperatures are in the low 70's. Warmer conditions are forecast for this week. There is a chance of showers after Thursday (June 20).

Apple growers reported seeing wilting shoots from fire blight symptoms late last week. This would correspond with the last bloom infection on June 4. Blossom blight symptoms from all bloom infections should be apparent. Apple fruit are waxy enough to be fairly resistance to fruit scab infection. Powdery mildew fruit symptoms are showing up in apple.

Strawberry harvest is underway throughout the region. Some growers report problems with fruit rots.

Raspberry and blackberry growers should maintain fungicide protection of the green fruit.

There will be a Blueberry IPM meeting at the Trevor Nichols Research Complex on Thursday, June 20 from 3:00 PM to 5:00 PM.

Cooler temperatures last week and continued rain events at most farms resulted in fruit crops that looked very typical for this time of mid-June. However, our season is still running about five days behind the last four seasons and a few days behind normal. With hot weather forecast later in the week and through the weekend, our season might jump ahead a few days. There was some scattered hail reported with thundershowers over the weekend. Soil moisture supplies are adequate to abundant. Soil temperatures have jumped into the low 70's on a few of the warmer days.

Codling moth trap catches remain high across the region this past week. Many trap catches are in the range of 50 to 80 adults. Most growers applied an insecticide late last week for the early codling moth control. With sustained trap catches that are seeing a second control application will be necessary at just about all farms. Fresh plum curculio stings have been seen at several farms. Oriental fruit moth trap catches have been fairly low. Flagging from Oriental fruit moth on apple terminals has been observed at several farms now. We are beginning to catch obliquebanded leafroller in traps and have seen a few large obliquebanded larvae. Green apple aphids are starting to show up at several farms, however their numbers have been kept in check by predators for the most part. White apple leafhopper adults are easy to find at most farms. Generally, I am seeing levels of one per leaf. No potato leafhopper has been observed as of yet. European red mite egg laying and hatch continues, however their numbers seem to be in check thus far this season from predators. Spotted tentiform leafminer are now pupating for the second generation. There is very little leafminer damage thus far this year. Apple skeletonizers have been seen at a few farms.

Apple scab spores were not trapped at either of our two locations in rain events last Saturday and Sunday morning (June 15 and 16). We have called an end to primary apple scab season in Southeast Michigan. Apple scab lesions continue to show up on the foliage and are now being found on fruit. Sheet scab is causing early defoliation of many crab apples and wild apples this year. This is an indication of how heavy the apple scab pressure was this year. No fireblight shoot strikes has been seen as of yet and powdery mildew symptoms continue to show up across the region in most apple blocks.

Pears continue to size well with most being around a 1 inch in diameter. Very little pear psylla has been seen this year. No fire blight strikes have been found.

Peaches continue to size very well, we are not at pit hardening as of yet. The peaches, which are enlarging, are going to be a harvestable fruit. There are many blocks of peaches where small fruit is also present and hasn't dropped as of yet. Hand thinning of peaches in the Romeo area will begin later this week. No green peach aphid has been observed as of yet. Oriental fruit moth flagging is rare in peaches this year. Bacterial spot is starting to show up, as is some peach leaf curl.

Summer Raspberries are at early fruit set.

Fall red raspberries continue to put on a fair amount of new growth. There have been some early reports of raspberry cane borer beginning to kill terminals. There continues to be a fair number of growers reporting dieback of canes this summer. This dieback was caused from freezing temperatures where the young shoots were exposed.

Blueberries continue to size fairly well. Mummy berry shoot strikes have been seen at a few farms. Phomopsis canker has become more prevalent and easier to spot over the last week.

Degree accumulations are running about six days behind normal for much of the Grand Rapids region.

Primary apple scab season is now over for 2002. Lesions from the last infection period should start to be visible in commercial blocks this week if you are going to see them. Now is a good time to scout blocks very carefully for primary scab lesions to make sure you are clean from scab this year. If you have scab showing up in blocks, you will have to maintain a fungicide program that protects fruit for several more weeks.

Bacterial canker in sweet cherry is causing some young dwarf trees to look pretty bad. Copper applications in blocks with bacterial canker will need to be made this fall. Nothing can be done at this time.

Plum curculio was really active last week in all tree fruits, and seems to be declining somewhat, but there is still some egg-laying damage being seen. Be sure your cover sprays are maintained for plum curculio.

Spotted tentiform leafminers are in the mine stage. Now is a good time to do a thorough scouting to determine the number of mines per leaf that are present from this first generation. Also, make counts of the number of parasitized mines. If there are more than two to three mines per leaf, a target spray should be considered when the second generation is vulnerable. This threshold is higher if 30 percent parasitism is present in the sample.

Codling moth continues to fly. Since the regional biofix of May 27, we have accumulated over 300 GDD50 since this biofix. Second cover sprays for codling moth for high-pressure blocks should be considered in the next seven to ten days.

Obliquebanded leafroller have just started to late last week. Numbers were very low and not present in every trap. A biofix will most likely be set soon.

Redbanded leafroller and other miscellaneous leafrollers can be found in commercial blocks with minimal insecticides. Most are in the third instar and can still be controlled with cover sprays.

White apple leafhopper nymphs can be found regularly. Normally a threshold of one to three per leaf this early in the season will lead to high numbers in the fall. For blocks with a light crop load and vigorous foliage, this threshold could be increased before control may be needed.

The blueberry varieties Bluecrop and Blueray have entered the "late green fruit" stage and Jersey is in "early green fruit." Growers started to spray against insect pests, mainly leafrollers and fruitworms. We are finding active leafroller feeding and presence of larvae in Ottawa County. Early in the season we detected large numbers of redbanded leafrollers in most blueberry fields and we expected substantial damage during late bloom attributed to larvae. During the past week we found in some fields a significant number of shoots with leafroller feeding, especially on the top portion of the bushes. However, most of the hibernacula were empty with signs of predation and only on the bottom we found larvae in numbers requiring chemical control. Traditionally, early season leafroller damage has been attributed to obliquebanded leafroller and the leafroller monitoring program has been established to detect obliquebanded leafroller and time pest control actions. We collected larvae from these infested fields and we brought them to TNRC for identification. Our preliminary identification indicates that only 1 out of 50 larvae was obliquebanded leafroller and two were redbanded leafrollers. The remaining larvae seem to correspond to Pandemis leafroller, a species we are not currently monitoring for. We expect to have a final identification upon the emergence of the adult stage. In addition to leafrollers, the cranberry fruitworm has been active in most blueberry fields in West Central Michigan. In some places, captures of adult cranberry fruitworm varied between 13 and 34 moths per trap per week and cranberry fruitworm feeding and larvae were found at Grand Haven, Michigan. We believe that the peak flight of the adult cranberry fruitworm generation occurred during the past week.

Another insect pest occurring in West Central Michigan at this time is plum curculio. The first reports of damage are from Holland and Glenn, Michigan. In places where we found plum curculio, the damage occurred at the edges of the blueberry fields facing woodlots or near plum trees. So far, only in one place plum curculio has required chemical control.

With respect to diseases, phomopsis is the predominant disease observed in West Central Michigan blueberry fields but not all varieties seem to be equally affected. Phomopsis has been observed most frequently in Bluecrop fields affected by frost.

Last week was very wet and downright cold! Except for Wednesday (June 12), it rained every day. Recorded accumulations were 0.66 inches in Hart, 1.13 inches in Manistee/Bear Lake and 1.22 inches in Ludington. The soil moisture is still satisfactory.

In apples, fruit is showing size differentiation. The kings are from 14 mm in Red chiefs to 22 mm in Idareds. The next few days are going to be the best and probably the last opportunity this season to apply the thinners. With the predicted temperatures in high 70's and into the 80's, the weather will cooperate.

The rains all this past week did not result in any spore discharge indicating the end of the primary scab infections. This season has been unique in many ways than one. Our scab infections were few but prolonged and heavy. Scab lesions are present in many blocks through out the area. Growers are cautioned that before they "ease-off" on the fungicide applications they need to make careful evaluation of their apple blocks for scab presence.

Concerning fire blight, no reports of the blossom blight presence. Some shoot blight is starting to appear. Powdery mildew is present in many orchards. The weather conditions provided very challenging circumstances for the control.

Codling moth flight with the average catch of 11 moths per trap is still strong, though the count has gone down since last week. Applications for the first generation control of codling moth should be done this week. We are at or very close to the application threshold of 430 to 450 GDD50. Leafrollers continue to be scarce. They are mainly obliquebanded leafroller larvae in advanced stage of development. No reported catches of the adult obliquebanded leafrollers as of yet. There has been some shoot "flagging" in both apples and peaches due to the Oriental fruit moth damage.

European spider mites are still not a major problem. The upcoming hot days may change this situation and we need to be on a lookout for them. Rosy apple aphids continue to build their colonies. For now, they are still very few and very small

The pear crop load is generally light. Fruit is sizing well and is at or above 22 mm. There have been no reports of finding blossom blight nor have we found any shoot strikes. I would expect to see some appear this week. Pear psylla continues to be very elusive.

In peaches, there is great variability in a crop load among the blocks. Generally, there is about 25 to 30 percent of a potential. Fruit is sizing well getting into 20 to 24 mm range. Applications for the Oriental fruit moth control have started to go on last week. Lesser peachtree borers and greater peachtree borers are active. Trunk sprays for their control could go on this week. We are finding some green peach aphids in small numbers. There is no major problem with the spider mites at this time. Bacterial spot and leaf spot in general are common site in all blocks without exception. Powdery mildew is present in some blocks.

In plums, crop load is variable form block to block. Generally, it is much smaller than what the potential is. Fruit is getting larger and exceeding 18 mm. Plum curculio is of major concern according to the model. The control application should go on at 375 GDD50 after the full bloom. In our case, that means that the spray target date should be by the end of the week or early next week. Bacterial spot is predominant.

Tart cherry crop is getting smaller by the day. Some "good" blocks may have about 20 percent of the normal crop though majority will be in the category of 1 to 10 percent. Fruit, that we have left, is sizing well. The color has started to change to very pale green. The situation with sweet cherries is slightly better but not much. Fruit is generally 15 mm. Plum curculio is main threat. Since there are fewer cherries, the competition for the fruit in which to lay the eggs is going to be furies. Good cover is "a must." Peachtree borer complex needs to be addressed. Trunk sprays could go on at this time. Powdery mildew is a common site. Last weeks rains have caused several heavy infection periods of cherry leaf spot. Leaf lesions from the previous infections are now visible. Disease pressure has been strong resulting in cherry leaf spot lesions in many blocks through out the region. Bacterial canker on both sweet and tart cherries is common site. Forecasted high temperatures this coming week could bring the onset of "cherry-yellows" and intense leaf drop.

This past week was cool and wet, with rainfall occurring three or four days during the week. The wetting events in NWMI ranged from 53 to 127 hours, depending on location. Rainfall for the week at the NWMHRS totaled 1.81 inches.

It's hard to find tart cherry trees with enough fruit to justify harvest. Plum curculio is a threat in all stone fruit crops.where crops exist. If crops are non-existent, insecticides need not be applied. However, if trunk sprays for borers have not been applied where needed, they should be applied as soon as possible. Cherry leaf spot infections are common. This past weekend the rains resulted in a high infection period. Yellow leaves will start to show up next week from cherry leaf spot and sour cherry yellows. Be careful not to confuse the two. Leaves with cherry leaf spot will often have white mycelia on the under side.

Grapes should be getting a very important fungicide spray 10 to 14 days before bloom. This spray is important to control powdery mildew, black rot and phomopsis. Potato leafhopper and rose chafer could show up anytime now.

Abnormally cool temperatures have persisted through much of the growing season thus far, with seasonal GDD50 totals generally remaining 50 to 100 units below normal for mid-June. With the approach of summer solstice this Friday (June21 at 9:11AM), however, changes are underway that should result in an extended warmer, more seasonable pattern that will help eliminate some of this deficit. Both short and medium-range forecast guidance now strongly suggests the gradual retreat of the westerlies (and embedded jet stream) northward into Canada, which will leave a broad upper air ridging pattern across the Upper Midwest and keep cooler air masses well to the north of Michigan.

In the short term, a weak weather system moving along the U.S. Canadian border will bring the chance for showers and thunderstorms first to northern sections of the state by late Wednesday (June 19) and statewide Thursday into Friday. While some isolated areas may see 0.5 to 1.0 inch amounts (especially in northern sections of the state), a real coverage of the precipitation is expected to remain scattered. Look for high temperatures to move into the 80's in most spots, with lows increasing into the 50's and 60's through the early weekend. A frontal system will move across the state later in the weekend, but temperatures are expected to remain near or above climatological normals into early next week at the minimum. The formation of the upper air ridge mentioned above is the dominant feature in the medium-range outlooks.

Both the 6-10 day and 8-14 day (covering June 23-27 and June 25-July 1, respectively) call for above normal temperatures. Precipitation totals during these time frames are forecast to be near normal in most areas of the state, and possibly towards above normal levels in western sections of the Upper Peninsula. Due to good agreement among the various forecast tools used to create the outlooks, relative forecaster confidence is considered greater than normal for the season.