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| Fruit Crop Advisory Team Alert newsletter | |||||||
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| Vol. 23, No. 3, April 15, 2008 |
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| In this issue Small fruit news New insecticides give grape growers more options for 2008 Now is a good time to monitor for mummy berry in blueberries New herbicides registered for blueberry Blueberry IPM kick-off meetingOther news Gisela rootstock pruning/training workshop New ag weather station installed: Romeo (Macomb County) Regional reports Weather news |
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| New insecticides give grape growers more options for 2008 In the past few years, the grape industry has received registration of many new insecticides. This is good news for grape growers who must maintain insects below economic injury levels in a time of increasing restrictions on conventional insecticides. The grape entomology program at Michigan State University evaluates insecticide performance in our Concord, Niagara and hybrid vineyards at the Trevor Nichols Research Complex. Each year, we run these trials against grape berry moth, Japanese beetle, and in recent years, potato leafhopper, testing the new products against each other and against a standard insecticide program. Our results have helped convince manufacturers and the EPA to register some of the new insecticides listed below, and they help provide information on which to base our recommendations. These products vary in their performance across different types of insect pests, the residual control they provide, and their safety to biological control agents. We have described their performance below to help growers integrate these products into their IPM programs. Reasons to consider new insecticides as part of a grape IPM program include: 1) Some are more effective against key pests than current standard products; 2) Using new chemical classes can prevent insecticide resistance, 3) Reduced impact on biological control agents of some of these products can reduce the risk of pest outbreaks, and 4) Greater safety to workers and the environment. This is a great time to learn about new pest management tools, including insecticides, to prepare for the busy growing season ahead. Talk to other growers who might have tried some of these products, attend grape grower meetings organized by the Extension service in your area, and read the new Extension grape management guides for your region. You can also see the labels for these products at the www.cdms.net website. |
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| Actara 25WG (Syngenta) is a neonicotinoid insecticide that is locally systemic, so it spreads in the foliage, protecting it against wash-off. This insecticide is labeled at 1.5-3.5 oz and is very effective on leafhoppers, beetles and other foliage feeders. Admire Pro (Bayer CropScience) is labeled for leafhoppers, scale, mealybugs and phylloxera. This is the same insecticide as Provado, in a different formulation for soil application. The label states that application can be made using a chemigation system or through soil application followed by irrigation. In our trials, this product provided three weeks of control of potato leafhopper when chemigated on vines grown on a drip system at the first sign of leafhoppers. However, performance was poor when we applied it as a band under irrigated or non-irrigated vines. This suggests that sufficient uptake of this insecticide (and most other systemic insecticides we tested) is only possible on vines with roots trained to emitters. A later application, in late June, in a drip-irrigated vineyard was also shown to protect leaves from Japanese beetle feeding. This product has a 30 day PHI. Assail 30SG (Cerexagri) is a neonicotinoid insecticide with activity on leafhoppers and other leaf-feeding insects. It also has performed very well in vineyard trials against rose chafer (equivalent to Sevin) and it provides vine protection against Japanese beetle feeding. Assail is also labeled for use against the foliar form of phylloxera. Avaunt 30WG (DuPont) was registered in mid-2007 and is a member of a new class of insecticides called the oxadiazines. It is labeled for Japanese beetle at 3.5-6 oz/acre. This insecticide has shown good activity on grape berry moth in our small plot trials, providing a high level of control after bloom and in the mid-season, but lower control after veraison when berry moth infestation increases. The label directs growers to use a 5-6 oz rate for berry moth control. It should also have broad activity on other pest types, including leafhoppers, making it useful for growers aiming to control multiple insect types. Baythroid XL (Bayer CropSciences) has high activity on a broad range of insects. At the 3.2 oz rate, our trials have shown excellent activity against grape berry moth and Japanese beetle. This product is also very active on Asian ladybeetles, providing a week of control of this harvest-time pest at a 2.4 oz/acre rate. This has a 3 day PHI. Brigade 2EC (FMC) is the same material as Capture 2EC (FMC), labeled from 3.2 to 6.4 oz per application, with a 6.4 oz limit. These products are pyrethroids with high activity on a broad range of insects. At a 3.2 oz rate, Brigade has excellent activity against grape berry moth with higher rates giving longer residual control. Control of beetles and leafhoppers is also expected to be high. This product was very active on Asian ladybeetles at a 2.4 oz/acre. This has a 30 day PHI. Delegate 25WG (Dow AgroSciences) was registered in the past few months, and is a member of the spinosyn class of insecticides. It has activity on moth pests and we expect it to have high activity on grape berry moth. However, we have not yet had a chance to test this in Michigan for insect control, and will run our first trials with it during 2008. Intrepid 2F (Dow AgroSciences) is a selective insecticide with high activity on grape berry moth and safety to natural enemies. Intrepid acts by disrupting the molting process in moths. Labeled at 4-8 oz/acre, there is a 16 oz seasonal limit. Grape berry moth eggs treated with this insecticide have low rates of hatching, and larvae that ingest residue die during molting. For these reasons, excellent coverage of clusters with spray is needed to achieve control. This product has long residual activity and is relatively resistant to wash-off. It has a 30 day PHI. Mustang Max 0.8EC (FMC) was registered in 2007 on grapes. At a 4 oz rate this pyrethroid gave excellent control of grape berry moth, Japanese beetle and multicolored Asian ladybeetle. It has a 1 day PHI. Venom 20SG (Valent) insecticide is in the same class as Admire Pro, and can be applied as a foliar or soil application. Foliar application provided excellent control of potato leafhopper in Traverse City vineyards during 2007, and it is also active on Japanese beetle. Venom has also shown high activity against potato leafhopper when applied through chemigation, and activity against other soft-bodied insects such as mealybugs or other leafhoppers is expected. Our tests of Venom have also demonstrated reduced grape berry moth infestation when used against the first generation of this pest. Venom is not recommended for late-season control of berry moth, but it showed excellent activity against Asian ladybeetle infesting ripe grapes at 2 oz/acre in our 2007 trials. It has a 1 day PHI. An important label change that may not have been noticed by all grape growers is the extension of the Re-Entry Interval for Imidan 70WP to 14 days in vineyards. The pre-harvest intervals have changed too: if more than 1.3 lbs is applied per acre, there is a 14 day PHI, compared with only seven days if a lower rate is used. To get the maximum activity from this insecticide, it should be applied in water with pH 5.5. If you don’t know the pH of your water supply, be sure to test it to find out if buffering is required. A final note: Our evaluations of insecticides are conducted with an airblast sprayer in mature juice grape vineyards that have vigorous growth. For this reason, our applications after July are conducted using 50 gallons of water per acre. This is especially important when the layers of leaves can block the clusters from spray material. If the insecticide doesn’t cover the cluster, grape berry moth control will be minimal, so we recommend growers pay attention to cluster coverage after bloom and make the necessary adjustments to maintain coverage through the last application. This effort will be rewarded with improved pest control. The insecticide testing program of the grape entomology program at Michigan State University is supported by the Michigan grape industry through the Grape and Wine Industry Council and National Grape Cooperative, by the agrochemical industry, and by the IR-4 Project. |
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| Now is a good time to monitor for mummy berry in blueberries It’s mummy berry season again. The mummy berry fungus enjoyed the snow cover this winter, which provided sufficient moisture for mummies to germinate. However, the rate of germination is lower than last year, with a maximum of 6 percent mummies germinated at this time. The extended cold weather seems to have delayed their development. In addition, some sites are very wet and many mummies may actually be submerged. It is not known how well they can survive waterlogging, but wet soils in general are conducive to disease. At this time, some mummies are showing small finger-like extensions (apothecial initials) and some have small trumpet-like mushrooms (apothecia) ranging from having pin-prick size openings to about 1-2 mm in diameter. At 2 mm (1/12 inch) in diameter, they can start to release ascospores. However, the most spores are released when apothecia are 5-10 mm in diameter (1/4 to 2/5 inch). If there is no leaf tissue on the bushes, it does not matter since infection cannot take place without green tissue being visible. The mummies typically germinate over several weeks to a month, depending on temperature and soil moisture, so there may be more waves of germinating mummies ahead. What to look for Blueberry growers should be monitoring for mummies with trumpet-shaped mushrooms (see pictures). The number of germinated mummies (specifically the number of visible apothecia) is a better predictor of disease than simply the number of mummies under a bush, since germination is prerequisite for ascospore release and disease development. Mummy berry occurs primarily at wetter sites and in poorly drained areas; therefore scouting should target those sites. Dry, sandy sites may not have any mummies at all. The mummy berry fungus shoots ascospores out of the apothecial cup as soon as the cup diameter is about 2 mm (1/12 inch) wide. Ascospore release continues until the cup collapses. Longevity of the mushrooms is affected by temperature close to the ground, e.g., at 70ºF, the mushrooms may live for less than a week, whereas at 50ºF, they can last two to three weeks, and at 40ºF up to four weeks. At higher temperatures, the mushrooms expand more quickly (they can almost become dime-sized) and release more spores per day than at lower temperatures. A severe freeze may damage the cups, but research shows that they can partially recover their ability to shoot ascospores after exposure to temperatures of 22ºF and above. The ascospores are windborne and can travel fairly long distances (supposedly up to a mile). So even if you don’t have any mummy berry in your field, there is a chance that ascospores can drift in from other fields or nearby woods with wild or escaped blueberries. Stages of infection There are two stages of infection. First the developing shoots are infected by the ascopores released from the mummy berry apothecia. Shoot strike symptoms appear approximately two weeks after infection. Shoots are susceptible from bud break until they are about 2 inches in length. Sometimes flower clusters may also become blighted; these are called flower strikes. Both shoot and flower strikes are characterized by drooping/wilting symptoms and a layer of gray spores (conidia) on the surface. These conidia are spread by insects (primarily bees), wind and rain. Bees are attracted to the shoot and flower strikes due to their UV light pattern (a nifty trick of the pathogen) and pick up the conidia on their legs and bodies. Bees then inadvertently deliver the conidia to the flowers where infection takes place. The conidia infect the flower stigma followed by colonization of the developing fruit, which eventually mummifies and drops to the ground. Flowers are susceptible for about four days after they open. The more shoot strikes there are and the better the weather for pollination, the greater the risk of flower and fruit infection. Cultivars such as Berkeley, Bluetta, Blueray, Earliblue, Jersey, Nelson, Patriot and Weymouth are susceptible whereas Bluecrop, Duke and Elliott are moderately resistant to the disease. Some cultivars are more susceptible to shoot strikes and less susceptible to fruit infection, whereas others are just the opposite. Control While there are multiple fungicides registered for mummy berry control, Indar consistently has outperformed other fungicides for both the primary and secondary phases of the disease in Michigan. Indar is a sterol inhibitor fungicide and therefore prone to resistance development in target fungi. It is recommended to limit the number of sprays of Indar to a maximum of two or three per season (five are allowed per the label). Orbit (propiconazole) and PropiMax (propiconazole), which are in the same chemical class as Indar, now both have a supplemental label for blueberries. Indar, Orbit and PropiMax all have a 30-day PHI. In small plot trials in Michigan, we found that Orbit was similar to Indar in the control of shoot strikes, but did not perform as well as Indar for control of fruit infection. PropiMax has not been tested in Michigan, but is expected to behave similarly to Orbit. For fungicide resistance management, it is important to alternate SI’s with fungicides in different modes of action, such as Bravo (fair to moderate efficacy), Captevate (moderate to good efficacy) Topsin M + Captan or Ziram (moderate efficacy), and Serenade (moderate to good efficacy). Systemic fungicides such as Indar and Topsin will likely provide better coverage of the flower parts (the stigma specifically). Cabrio and Abound have shown poor to fair efficacy in past trials in Michigan. While Pristine did not perform particularly well for control of mummy berry shoot strikes in small-plot trials in Michigan, it provided good control of fruit infection. We suspect that the activity of Pristine is better at higher temperatures; it therefore may be a good option during bloom as it also controls anthracnose, Botrytis and Phomopsis twig blight and canker.
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| New herbicides registered for blueberry Supplemental labels have been issued for Callisto (mesotrione, Syngenta Crop Protection) and Chateau (flumioxazin, Valent Biosciences) for use on blueberry. The supplemental labels are part of the Section 3 federal labels and do not have expiration dates. Callisto provides preemergent and postemergent control of several broadleaf weeds that are troublesome in blueberries, including several pigweed species, chickweeds, horsenettle, lambsquarters, marestail, eastern black nightshade, ragweed, and smartweed. Callisto has limited effect on grasses. Callisto is absorbed by weeds through the roots and leaves. Apply Callisto before bloom at up to 6 fl. oz. per acre. This amount may be split into two 3 oz. applications at least 14 days apart. Apply as a directed spray to soil beneath the bushes. The addition of crop oil concentrate (COC) will improve postemergent activity, but combinations with postemergent herbicides such as Gramoxone or Rely are suggested for very weedy areas. Callisto with COC may injure blueberry leaves and young stems. Callisto can be used on young, non-bearing and bearing bushes. Avoid plant contact as much as possible. Chateau is primarily a preemergent, soil-active herbicide. Chateau has some postemergent activity when it is applied with a non-ionic surfactant or COC, but it is more effective as a burndown in combination with postemergent herbicides such as Aim, Rely, Gramoxone, or Roundup. Troublesome blueberry weeds controlled by Chateau include chickweeds, dandelion, common groundsel, lambsquarters, eastern black nightshade, several pigweeds, ragweed and most annual grasses. Application rates are 6 to 12 oz product per treated acre. Do not apply Chateau after bud break through final harvest. Do not mow treated areas between bud break and final harvest, because dust created by mowing may settle on blueberry leaves and cause injury. Do apply to bushes established less than two years. Rain or irrigation is needed to activate Chateau. One last change is a new formulation of an old herbicide. Casoron CS is a micro-encapsulated liquid formulation. The older granular product, Casoron 4G, is hard to uniformly apply beneath blueberries. Casoron CS can be applied to bushes that have been in the ground at least six months, and should not be used on light sandy soils. Casoron CS works best when applied in the late fall or early spring. Susceptible weeds include many annual grasses and broadleaves and some troublesome perennials, such as wild aster, horsetail, red sorrel, yellow woodsorrel and bindweeds. Callisto, Chateau and Casoron have weed control spectrums somewhat different from the commonly used preemergent herbicides such as Princep, Karmex and Sinbar. They also have different modes of action, so it may be helpful to rotate these products over time to broaden the weed control spectrum and discourage development of herbicide resistant weed populations in blueberries. |
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| Blueberry IPM kick-off meeting A Blueberry IPM meeting to kick off the season will be on April 23 from 12:00-3:00PM at the Trevor Nichols Research Complex in Fennville, MI. Lunch will be served. This meeting will cover many topics:
This is a free meeting. Additional IPM meetings will be held between bloom and pre-harvest. |
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| Gisela rootstock pruning/training workshop Northwest Michigan Horticultural Research Station Dr. Greg Lang and Dr. Nikki Rothwell will host a workshop for growers interested in pruning and training sweet cherries on Gisela rootstocks. Dr. Lang has a tremendous amount of experience with these rootstocks, which he will share in presentation format and with pruning demonstrations in the field. The workshop begins at 11:30AM on April 23, at the NW Michigan Horticulture Research Station. Dr. Lang will present his data, which will be followed by a round table discussion over lunch which is provided. The on-farm demonstration will be held at Jim and Gary Bardenhagen’s, where we will learn how to train newly planted, two, and three year old sweet cherry trees. Please RSVP with Jackie at the NW Station (231-946-1510). |
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| New ag weather station installed: Romeo (Macomb County) Over the last two weeks a new agricultural weather station has been added to the state-wide Michigan Automated Weather Network (MAWN) by that generates the data for Enviro-weather. The station is in Romeo and is located at Westview Orchards and Cider Mill. The addition of this weather station in Macomb County will fill another gap in the MAWN network that we rely upon heavily for agricultural weather across the state. This new weather station and the data it generates will be particularly helpful for not only fruit growers in the region, but for the vegetable and landscape industries as well. Many thanks to the Jacobson, Schumacher and Roy families of Westview for their contributions to get this station up and running. Information on this station can be assessed at www.enviroweather.msu.edu. |
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Regional reports Cool temperatures with highs near 60ºF and near 40 ºF slowed down plant development. We are at the lowest GDD accumulation since 1996 and are about two weeks behind recent years. It rained most of last week and soils are wet. Fruit buds on most crops are swollen. With bud growth, there is increased danger for freeze damage. Morning freezes on Monday, April 14 (low 27) and Tuesday, April 15 (low 25) caused only a little damage to stone fruit. Even with our delayed spring growth, there is still a good chance of temperatures into the upper 20s into May, which could cause damage to developing buds and flowers. The forecast is for warmer conditions with rain showers Thursday.
Tree fruit Tree fruit buds are swollen and we are beginning to see green tissue. Mark Whalon reports that plum curculio adults were active on April 1 in East Lansing. Temperatures were too chilly for insect activity last week. Now is the time to put out Oriental fruit moth and redbanded leafroller traps. Apricot buds are at red bud to first white. At this bud stage, injury would occur at temperatures in the mid-20s. Peach buds are at swollen bud to calyx green. At this bud stage, injury would occur at temperatures in the low 20s. As fruit buds become more swollen, it is easier to determine the buds that were killed by winter cold. Winter damage was generally light in the major peach producing area. Green leaf tissue is emerging from leaf buds. It is too late to apply protectant sprays for peach leaf curl. Recent rains were certainly infections for this disease. There is probably some benefit to catch up sprays to reduce peach leaf curl where earlier sprays were missed. The most effective material would probably be chlorothalonil. Now is the time to put out pheromones for Oriental fruit moth for mating disruption. Mating disruption has been very successful against this pest. Cherry buds generally are at green side. Some tart cherries are at green tip and suffered a bit of damage from the freeze Monday morning. At this bud stage, injury would occur at temperatures in the mid-20s. The window for applying copper as a dormant spray to sweet cherries to reduce bacteria canker is ending. Copper can still be applied to tart cherries, which can tolerate copper very well. In plums, Japanese plum buds are at tip green. At this bud stage, injury would occur at temperatures in the mid-20s. European plums show only a slight swelling. At this bud stage, injury would occur at temperatures below 20ºF. Apples are generally at silver tip. Early varieties are at green tip. At this bud stage, injury would occur at temperatures below 20ºF. We expect to see quarter inch green later this week, at the quarter inch bud stage, damage would occur in the low 20s. Apples are susceptible to apple scab. Because of the mild winter, we expect scab spores from the leaf litter will be ready as soon as green tissue is available for infection. Growers should be ready to apply scab sprays. Pear buds are swollen. At this bud stage, injury would occur at temperatures below 20ºF. Few pear psylla adults are out and no eggs have been found. More adults should emerge soon when warm weather returns. Small fruit Small fruit have broken dormancy, but we are still in the window for lime sulfur applications in blueberries, grapes and brambles to suppress diseases that overwinter on the plant. Blueberry fruit buds are swollen and leaf buds are beginning to move. At this bud stage, injury would occur at temperatures below 20ºF. It is time to look for mummyberry mushrooms. Mushroom development begins about the time green tissue shows on the leaf buds and new mushrooms were reported last week. We should see a lot of mushrooms after several warm days warm up the soil. There is standing water in many fields. Grapes are at scale crack. At this bud stage, injury would occur at temperatures in the mid-teens. New strawberry leaves are emerging. At this development stage, injury would occur at temperatures below 10ºF. Growers are applying herbicides and putting down irrigation pipe for frost/freeze protection and straw mulch. Raspberry and blackberry buds are at green tip. At this bud stage, injury would occur at temperatures below 20ºF. Growers are finishing pruning. Now is the window for lime sulfur applications to suppress anthracnose. Cranberry beds are coloring up, but the tip buds are still tight. Miscellaneous Growers are clearing brush. Quite a bit of copper has been applied to stone fruit. Some tree planting has occurred, but I expect more as the soil dries out. A lot of older cherry and apple orchards were removed during the winter and early spring. The next Monday Fruit Update meeting will be Monday, April 21 at the Fruit Acres Farm in Berrien County. |
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| 2 -- Southeast Bob Tritten Weather Our late start to the 2008 growing season has now been reversed with a string of 11 warm days and nights to push our season ahead of normal. Based on degree days, I think that our season is now running 5 to 7 days ahead of normal, and based on flowering stage we are about a week ahead of normal. As a horticulturalist, it has been very interesting and yet a bit frightening to see fruit growth and development occur so rapidly over the last two weeks. Cold temperatures last night and this morning are in the low to mid-30’s for most reporting stations across the eastern part of the state. Exceptions to this were Lapeer County and then a few stations in the Thumb that had temperatures in the 26ºF to 29ºF degree range. I think the fruit crop development was slow enough in those regions that there most likely will not be an issue with frost and freeze injury. In Flint area, we had a rooftop frost that occurred just before sunrise. Based on the weather predictions for tonight, I expect to see one more night of potential frost and freeze concerns, with low temperatures dropping a few degrees lower than this morning. In looking at the 10 to 14 day forecast, it appears that we are through the worse potential freeze issues. Our region has missed several good rains over the last three weeks. While our top soils are a bit on the dry side, for the most part we have more than adequate amount of subsoil moisture. Most fruit growers have been planting tree and small fruits and are wrapping up that process. These growers are now looking for some good rains to get those plants off to a good start. Early in my career as a district horticulture educator, I had several well seasoned fruit growers share their observations over their many seasons as to the strength and viability of our fruit flower bud and crop based on their observation of how forsythia have flowered that seasoned. Over the years, I have come to see that there is a great deal of truth in observing the vigor of the forsythia bloom and to make a projection on the viability and abundance of our fruit crop. This year’s forsythia bloom has been wonderful as I observe flowering from across the region. As I look at the potential fruit crop across the region, I would also say that we are off to a start of a great season. Southeast Michigan GDD totals for March 1 -April 28, 2008
Tree fruits Apples in southern tier counties of southeast Michigan are at green tip for most varieties. Apples in the Ann Arbor area to the north are mostly at silver tip; apples in the Flint area are at silver tip to bud swell. There continues to be a good crop of apple buds as I visit more orchards across the region. Growers in the south are making applications of copper to control early scab, and growers in other parts of the region are considering dormant oil applications for San Jose scale and mite control. Pear buds are continuing to show signs of swelling with no green tissue showing. I have seen two short periods of pear psylla adult activity, and over the weekend I began to see a more steady flight of pear psylla adults. No egg laying has occurred. Peach buds have swollen nicely and I expect to see some green tissue to begin to show in a day or two in most farms across the region. The window for peach leaf curl sprays has now been closed. A good crop of flower buds continue to be seen. Sweet and tart cherries are at swollen bud with no green tissue showing on either. It appears that we have a nice crop of both sweet and tart cherries. Plums are showing little evidence of bud swell. Small fruits Strawberries are starting to grow underneath straw mulch. I would recommend that growers begin to think about mulch removal later this week at most farms across the region. It appears that we have good winter survival of plants. Raspberries are at green tip on some varieties, while most are still at bud swell. I continue to see tip burn on summer red, purple and black raspberries as a result of winter injury. This tip burn should be pruned back to viable tissue fairly quickly. I have not seen any evidence of cane emergence from the ground on fall bearing raspberries. Blueberry buds continue to swell with no green tissue showing. I feel that we have a nice crop of blueberries coming along this year. I have not seen any evidence of mummyberry mushrooms on the ground underneath blueberries. Grapes are still dormant to early bud swell. |
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3 -- Grand Rapids Area There is still very little happening on the crop development front. Apple buds remain tight, but many varieties are showing silver tip and a bit more advanced than a week ago. Peach and cherry buds have plumped up, but only show a slight change from last week. Normal degree day accumulations at the Sparta weather station through April 14 should be 141 degree days base 42 and 51 degree days base 50. Current totals at Sparta are 97 base 42 and 28 base 50. With the forecasted temperatures, we’ll probably see some green showing by the middle or end of this week and could be at a quarter inch green in apples by next Monday or Tuesday. Growers are finished with winter pruning of apples and are completing brush removal from blocks. Ground applied fertilizer applications could be started soon, but with the price of fertilizers, growers should carefully time applications so that they are not wasted putting them on too early. Tree planting could start in another couple of weeks if the soil warms up and dries out a bit. Tree fruit pests Copper applications to sweet cherries should be started at the first signs of green tissue showing to help with bacterial canker. Apple scab spore rods have been out for two weeks. Single digit numbers of spores have been caught with the last two rain events indicating that there are mature spores out there and growers should be ready for scab infections as soon as green tissue shows up. European red mite eggs can be found, but numbers appear to be normal so far. Blocks that had high numbers of mites late in 2007, should be checked carefully and planned for regular early season monitoring for red mites. It’s not too early to start putting pheromone ties up for Oriental fruit moth in stone fruits or for codling moth in apples. Since there have been no pesticide applications made yet, it’s a very safe time to have workers doing this task. We rarely get this much extra time in the spring to do pheromone tie applications. Announcements The Ridge area Code-A-Phone is operational. The number is (616)451-8065. The Spring Spray meeting will be held Thursday, April 17 at Bill and Patrick Goodfellow’s farm on 12 Mile, just west of M-37 near Sparta. The meeting will run from 6:00 PM to 8:00 PM. |
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4 -- West Central The cool weather conditions continue with no significant change since last week. The nights of April 13 and April 14 were clear and frosty with the temperatures from low to mid-20’s in Manistee and Hart to mid-20’so low 30’s in Ludington. Since the vegetation did not move much, damage is not expected to be of any consequence to the production outlook. All apple varieties are in early silver bud. Pears are just starting to show bud scale separation with no indication of major swelling. Peaches are in swollen bud. European plums are still dormant and Japanese plums are in swollen bud. Tart cherries are just beginning to show scale separation and initial bud swelling. Sweet cherries are showing swollen bud. West Central Michigan GDD Totals from March 1 - April 13
Degree day accumulation is more than half behind last year’s. DiseasesAs for apple scab, Roto rods are in place for monitoring spore maturation and discharge. Last week’s rains did not produce any spore discharge yet. For peach leaf curl, we are moving out of the optimum control window. However, fungicide applications (Bravo) are encouraged up to bloom. Research has shown the application will be beneficial though somewhat less effective. This prolonged cold with daily frost occurrence will favor bacterial canker development. This opportunistic disease of a cool season will multiply reaching its peak at just about bud break. Bacteria has found a safe haven in the buds near the cankers or near the affected spurs as well as in the vascular tissue. It will invade the trees through the wounds resulted from frost and/or pruning. For detailed information regarding weather conditions, degree-day accumulations and weather forecast, visit MAWN (Michigan Automated Weather Network) http://www.agweather.geo.msu.edu/agwx/forecasts/fcst.asp?fileid=fpus53kgrr From there you can link to the MSU’s Enviro-weather system equipped that includes various models to be used as tools in disease and insect management. |
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5 -- Northwest GDD42 53 GDD50 15 Growth Stages at NWMHRS (04/14/08 - 8:00 AM) Apples are at early silver tip. Pears: Bartletts are dormant. Sweet cherries: Early bud swell. Tart cherries, apricots, plums and grapes are dormant. Weather The weather has been chilly so far this spring, and we have accumulated half of the growing degree days of last season. We had a few big rains in April: over one inch on April 1, 0.93 inch on April 9, and another 0.66 inch on April 11; in short, we have had good rainfall (3.06 inches). Crop report Most crops are still in the dormant stage, but we have seen early silver tip in Macintosh, Red Delicious and Gala apples. We are also starting to see early bud swell in Golds and Napoleons. Lots of pruning is taking place in the northwest, and inquiries have started for growers looking to secure honeybee colonies. Pest report The NWMHRS trap line was put up yesterday, and plum curculio emergence traps are also in place. No plum curculio were captured in the traps as of April 14. |
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Weather news Changes in the upper air pattern across North America were underway Tuesday, April 15. The troughing feature which has persisted across the central United States for much of the past few months is expected to gradually shift westward to the western United States by the end of this week. This will lead to continued wetter than normal conditions across Michigan, but with a noticeable increase in temperature. |
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