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The weather has been and will continue to be very hot. This can be stressful for the vines. Monitor as needed to make sure the vines and fruit are not lacking for water.
No unusual levels of rot have been reported and upright dieback symptoms have been reported in beds with a history of the disease or in beds with some sort of heat and/or water stress. Remember that fungicide applications at this time of the year will have a very small impact on field rot infection and upright dieback. Over the next couple of weeks, monitoring of weather conditions may be critical to avoid sunscald on berries. Scalding can occur with air temperatures as low as 85°F, especially on days with low cloud cover and low relative humidity (< 65%) and keep in mind that the risk of sunscald and heat injury varies from site to site and may depend on specific bed conditions. In addition to weather, irrigation practices, fruit size, and vine density can influence the risk of scalding. Scald damage can be prevented by using overhead sprinkler irrigation to cool down the fruit. Short irrigation periods can decrease canopy temperature by 4-10°F and avoid scalding as long as soils are not saturated and no puddling occurs.
If you have flea beetles out there and have numbers "too high" to count, you should spray Diazinon as soon as possible. Cranberry weevils (second generation) are out and abundant in some cases. The threshold for spraying is higher for the summer generation; an average of 9 is used to trigger a spray. Remember Actara is Zone II regulated and highly toxic to bees. If you are in a Zone II and use Actara, you must submit a form to MDAR within 10 days of the end of the month. Forms are available at the Station, CCCGA or on-line through MDAR's web site.
You should be well into scouting for CFW eggs now. Collect 50 berries per acre with a minimum of 200 berries per management unit. Repeat scouting procedure every 3-4 days until August 15. If CFW pressure is low through fruit set, it may be safe to extend your interval a little. If numbers trigger a spray, spray ASAP.
Yellow loosestrife is flowering out there now, which seems to be a bit earlier than we would typically see. QuinStar is a good option for yellow loosestrife control, but it has a 60-day PHI. Poast has a 60-day PHI. Chlorothalonil products and Stinger have a 50-day PHI. Callisto has a 45-day PHI.
If you have patches of dodder, you can spray them with concentrated Callisto applications. Spraying before dodder flowers is much more effective than spraying after flowers or seed are present. Select and Intensity are good options to control poverty grass. Both have a 30-day PHI, but get out there soon as treatment is best before the grass flowers!
If using granular NPK program, 25-30% of your total N goes out at fruit set. If using NPK/fish program, 30-35% goes out at fruit set. If only using fish, use 25% or 50%, depending on what you've done so far.
Early rot has already been reported on Early Blacks and Stevens. This fruit rot disease is one of the first to be observed during the growing season. Infected fruit have brown-dark brown spots with concentric rings and as infection progresses, black, pimple-like structure (pycnidia) may be visible on the fruit surface.
Virus-like symptoms have also been reported on Stevens. Tobacco Streak Virus and Blueberry Shock Virus can cause severe scarring symptoms on fruit. Special testing is required to confirm both viruses, so if you are observing unusual fruit symptoms and fruit scars please contact Erika at (508) 295-2212 ext.18/19.
Blossom 'blast', or heat injury to flowers, was observed in Crimson Queen. Heat injury in flowers and young tissues may occur with temperatures as low as 86F, especially in areas with poor vining or near water puddles. Heat injury and sunscald on fruit can be prevented by cooling the canopy with overhead irrigation. For more information, please call the Station and talk to Erika (x18) or Peter (x29).
You should be sampling fruit and inspecting for cranberry fruitworm eggs. We have been finding lots of hatched, dead and otherwise eggs, but you need to look to make sure you don't have a threshold number of unhatched viable eggs. Remember you can only do 9 oz/A of Altacor per season, which is usually 2 applications since most folks go with 4.5 oz/A. Delegate is good for later in the season as a "clean up" spray, if you can do it. For Spag, Altacor, Delegate, and Intrepid are your best choices. Altacor and Intrepid are preferred choices if you still have bees on your bog.
We have a 2ee recommendation for QuinStar: Application time can be reduced to less than 30 minutes if experience has shown that the existing chemigation equipment can distribute the product uniformly over the area to be treated. The label previously recommended injecting for 30-45 minutes. MDAR has approved the 24c for the use of Callisto as a concentrated spot application as well as using less adjuvant when chemigating the herbicide. You can use 1-4 pt/A instead of the 0.25% v:v, which usually means 1-2 gallons per acre. We should be getting copies of the supplemental label soon and will post it to our web site and distribute to ag suppliers.
We will be offering a workshop on how to use our new weed ID guide and do basic weed identification. It will be held on Tuesday August 4 9:30-11 AM in the library at the Station. Please let us know if you are coming (x10 or 21). The cost is $20 to attend and you get a copy of the guide.
We have gotten a few calls about gypsy moth. There is no recommendation to treat for the moths that folks are reporting (both brown moths and white moths); IPM recommendations target larval stages. To the best of our knowledge, gypsy moth has only one generation per year, contrary to some information going around in the rumor mill. You may see dead caterpillars on tree trunks. These have been infected with a fungus and they will die.
Altacor and Delegate are still your best choices for cranberry fruitworm control with respect to residual and bee safety compared to Diazinon, so we recommend using those products over Diazinon. If you are concerned about sprays going out in unstable weather pattern, Altacor should have good residual and rainfastness. Please use the traditional cranberry fruitworm timing for Howes, spraying 7-9 days after 50% out-of-bloom. This is still the best management strategy for this variety.
Now is the good window to use QuinStar for yellow loosestrife control, if you can use the herbicide as per your handler.
Dodder can be controlled with concentrated spot applications of Callisto. It is best to apply the herbicide BEFORE dodder flowers. Use 1-1.5 oz of Callisto per gal water plus an NIS or COC, also at 1.5 oz per gallon water. If it’s hot and humid, use an NIS. If it’s really hot and humid, wait until the weather breaks before applying any herbicide. Remember you cannot exceed 8 oz Callisto per acre. If you use 1.5 oz Callisto per gallon water, you can only treat approximately 7,600 sq ft or less than 1/5 of an acre.
Fruit set fertilizers should go out now for all varieties, if you have not already done so. Please consider using low P options whenever possible. The first and second numbers should be 1:1 or less, like 13-13-13 or 14-7-28.
Please let the Entomology lab know if you have a scale problem or if you think you have a problem. They can help you diagnose it and they want to know how much is out there. Timing for good control is critical so do not wait too long or try to time with other sprays; just go out and get it done.
You should be out there doing % out-of-bloom counts for cranberry fruitworm control and % IN bloom for fungicide and fertilizer decisions. Here are some numbers that we have gathered from Rocky Pond (Myles Standish State Park) and State Bog in East Wareham (as of June 22-23):
If the weather continues in this warm pattern, we could be hitting 50% oob for the hybrid varieties well before the traditional July 4th timing, so do your own calculations now and find out what % oob you have on your own bogs.
Please let the Entomology lab know if you have a scale problem or if you think you have a problem. They can help you diagnose it and they want to know how much is out there in the industry. If you have scale, it is time to spray. As far as fruit rot, it is also time to be putting out first fungicide. The window for controlling early season insects is closing unless you have really high numbers. These are cases that definitely need managing. Bloom time fertilizers go out around 75% bloom, you should check, but most likely many bogs are not quite there yet.
It is probably too late to be spraying for cranberry weevil (eggs are in the pods already) for most locations and varieties and for spag larvae. Adult Spag moths are out. If treating Spag with Intrepid or Confirm, apply 3 weeks after moth flight begins and again 10-14 days later. Conventional insecticides are applied 10-14 days after PEAK flight.
Now is the time to be monitoring for scale. Check the June 5 newsletter for more info. Bring samples into the Entomology lab for confirmation. Treatments should be going on in the next 2 weeks. If you are using pheromone traps to time sprays for BHF, Spag or girdler, traps should be out. Use 1 trap per 10 acres and place them on the upwind side of the bog so that the pheromone blows across your bog. Check them weekly (more or less depending on flight patterns) and clean or change them as needed. Record the moth numbers. Check descriptions of adult moths in extension materials as non-target species can get caught in the traps. Intrepid, Altacor, and Delegate go on several weeks earlier (based on when flight begins) than conventional products like Diazinon (based on when flight peaks), so make sure you know the time interval for the pest you are targeting.
The Keeping Quality Forecast for 2015 is GOOD. We got 7 out of 16 possible points. For beds with little or no disease pressure, 2-3 fungicides may be sufficient. Be sure to consider other important factors (e.g. drainage, plant vigor, rot history) in addition to the KQF when managing fruit rot. Call Erika at ext. 18 if you have questions.
Poast (sethoxydim), and Select and Intensity (clethodim) can be used for control of true grasses. Chemigation is NOT allowed for any of these products. Poast should be applied with a crop oil concentrate (COC). Grasses should have at least 6-8 leaves to provide enough surface area for absorption. Select 2EC and Intensity should also be applied with a COC. Select MAX and Intensity One can be applied with a nonionic surfactant (NIS). Application of a Select or Intensity product is prohibited between hook and full fruit set, but they only have a 30-day PHI whereas Poast has a 60-day PHI. Poast has no timing restrictions, however. If you are not sure if you have a true grass, send me (email@example.com) a photo or bring a sample in before treating.
We will be having a bogside workshop on this coming Tuesday June 9 from 8-10 AM at the Station with 2 contact hours offered. The focus will be cranberry fruitworm and fruit rot management. We will meet outside if the weather is nice; in the library, if not so nice.
Many growers have been treating with Avaunt over the past few weeks for winter moth or weevil. Winter moth should be finishing up so it's is time to stop chasing. Weevil has been reported over threshold and it should be treated if you have high numbers. Spag is out and larvae are getting picked up in sweep nets now. We had also heard of high counts (8 larvae) of black-headed fireworm. Marty also reports seeing some weird spanworms out there, but nothing to be worried about. If you are using pheromone traps to time sprays for BHF, Spag or girdler, traps should be out by June 1. Use 1 trap per 10 acres and place them on the upwind side of the bog so that the pheromone blows across your bog. Check them weekly (more or less depending on flight patterns) and clean or change them as needed.
I have had a couple of questions about treating for control of poison ivy. Spot-applications of concentrated rates of Callisto with either COC or NIS give good control. Our 2-year trial showed better control in Year 1 when we treated mid-June/early July compared to late May/mid-June applications, but both decreased PI and cranberry growth rebounded. The difference between the two timings became much smaller in the second year when we treated in 2 consecutive years. The bottom line is if you have poison ivy in spots and have time to treat it, go for it. Two applications per year are recommended and they must be separated by at least 14 days. Use up to 1.5 oz/gallon with either NIS or COC, but if it is looking to be hot and/or you have flowers out there, I would favor the NIS. We have been working with Syngenta and we should have a Special Local Needs label for spot-treatments very shortly.
Early hybrids such as the Mullacas, were in hook stage earlier this week. So, for the very early varieties, first fungicide is just around the corner.
We have heard of very high counts of gypsy moth over the past week. If weevil is not in the mix, Delegate is a good choice for the cutworm pests, as is Intrepid. Sevin can also be a good choice if your caterpillars are dominated by gypsy moths. Humped green fruitworm has also be scouted.
Winter moth larvae are out and growers are spraying to control the immatures. We sprayed Rocky Pond bog in Miles Standish Forest on Monday for WM control. The larvae are very small; using a hand lens or other magnifier to see them, if needed (see pictures on first page of May 1 newsletter). Scouting for other early season insects should be well underway. Although the spring has been cool, native varieties are at 25 F for frost tolerance and the hybrids are at 27 F (cabbage head stage). Carolyn feels that the vines have “caught up” to their average growth stage for early May.
Frost season is underway! As of April 23rd, most bogs had reached white bud stage. Some bogs that iced-out late were lagging behind a bit. Starting on April 27th and updated as the plants advance, photos of tolerance stages will be posted on the Station website.
Winter moth found on cranberry! The Entomology Lab reports tiny winter moth (WM) larvae have been picked up in sweeps in Plymouth and Rochester! Despite temps below 60, a few larvae per sweep net have been found. They are incredibly tiny but they are out.
If you are going to treat for WM, consider Intrepid, Avaunt or Delegate given that larvae can now be found; they will only grow bigger by eating the tiny buds! Although the numbers may be below threshold, they will get into buds and may be harder to kill once inside. The threshold of 18 per sweep set is not a long-standing "tested" number; it is a guideline to help management. Consider only treating pieces where the higher numbers are found and perhaps at reduced rates of insecticide, and then sweep again. Possibly, the larvae are from the bog and a spray would stop them, but it is also possible larvae may come in from surrounding blueberries and trees and may continue "ballooning" in, and maybe both. Another consideration is size of cranberry bud… if the buds are too small, larvae may just die, if buds are bigger (i.e., sanded pieces, early varieties, warm locations) larvae may do well and grow faster.
Heather Faubert, University of Rhode Island Extension reports that winter moth eggs started hatching on April 19. Over the past week, all the eggs at the monitoring tree in Kingston, RI have turned blue and hatched. She expects all eggs have hatched by now in our area as well.
It is still too early to be spraying for winter moth in cranberry, however, we wanted to keep you up to date on WM progress in various spots throughout the region. According to Heather Faubert, University of Rhode Island Extension, winter moth eggs started hatching on Sunday, April 19th in Rhode Island. Many blueberry and apple growers sprayed insecticides over the weekend, protecting flower buds.
As of April 20 (using a base of 40°F starting Jan 1), East Wareham (02538), and Sandwich (02563) had 138 GDD, East Freetown (02717) had 156, Carver (02330) had 129, and South Dennis (02660) had 128. This is still much lower than this time last year (range was 185 to 261 GDD). MA's target for winter moth hatching is 177-239 GDD. To check your area: http://adstest.climate.weather.com/outlook/agriculture/growing-degree-days.
Management: Timing is important because if the newly hatched caterpillars are allowed to crawl inside the expanding buds, they are protected from any insecticide that might be applied. Scouting should be started early (ca. May 1) to catch these populations. Avaunt, Delegate, and Intrepid are the best choices for control of WM on cranberry. If you have a history of WM, you may need to apply a prophylactic spray early in the season. The Action Threshold for WM is 18 average per sweep set.
We do not recommend oils at this time (even though other small fruit growers use them against WM). Marty has not found cranberry to be listed on an oil label (if you know differently, please tell us).
For more information about Winter Moth, see IPM message dated April 9th below.
We sent out a Winter Moth fact sheet in the April 8, 2015 newsletter. Look for it! These photos are included in the fact sheet:
It's not too soon to be thinking about winter moth. We are a bit lucky in that we can usually find WM in blueberry ahead of when they will be in cranberry. However, you can track potential egg hatch yourself. Eggs hatch when temperatures average around 55°F. It is believed that egg hatch in Massachusetts occurs when approximately 177-239 growing degree days (GDD) above a base of 40°F (starting Jan 1) have accumulated.
GDD can be variable. As of April 8, East Wareham (02538), Norton (02766), and Sandwich (02563) have 42 GDD, East Freetown (02717) has 40, Carver (02330) has 27, and South Dennis (02660) has 37. This is much lower than this time last year (range was 89 to 138 GDD). Visit http://newa.cornell.edu/ or http://www.weather.com/outdoors/agriculture/growing-degree-days/01002 to calculate the Growing Degree Days for your location.
Management: Insecticide sprays timed to coincide with egg hatch are the most effective way of controlling this pest. The timing is important because if the newly hatched caterpillars are allowed to crawl inside the expanding buds, they are protected from any insecticide that might be applied. Scouting should be started early (ca. May 1) to catch these populations. Populations may re-occur as larvae can balloon in. Avaunt, Delegate, and Intrepid are the best choices for control of WM on cranberry. If you have a history of WM, you may need to apply a prophylactic spray early in the season. The Action Threshold for WM is 18 average per sweep set.
Organic growers can use Entrust (spinosad), or one of the Neem products such as AzaDirect, Neemix, or Ecozin in place of the insecticides listed in the table above. Products that contain B.t., may also be effective but depend on the caterpillars ingesting enough product to be effective.
For detailed information concerning the biology and management of Winter Moth, visit the following: http://extension.umass.edu/landscape/fact-sheets/winter-moth-identification-management http://extension.umass.edu/landscape/fact-sheets/winter-moth-overview
For current regional updates on the Landscape message:
UMass Cranberry Station • 1 State Bog Road, PO Box 569, East Wareham, MA 02538 • firstname.lastname@example.org • Phone: 508-295-2212 • Fax: 508-295-6387
The UMass Cranberry Station is part of The College of Natural Sciences.