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News on the disease and insect fronts has been quiet. We have seen some flea beetle damage but reports are fewer. Remember that our fungicides work as protectants, not as curatives. That means if you apply a fungicide AFTER you see the rot, it will do no good. In general, applying fungicides this late is of little use. Consider managing your irrigation to allow the vines to be dry as much as possible; this helps to limit fungal growth. It is getting to be the time to put out bud set fertilizer applications if that is part of your nutrition program. This is usually 20-25% of your total N goes out in this dose.
We are at the end of the window to use Admire or related products for grub control. If your bees are off the bog, you can apply Actara and Admire if needed. 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.
If your bees are off the bog, you can apply Actara and Admire if needed. Cranberry weevils (second generation) are out and abundant in some case. 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. Admire or related products for grub control are aimed at the immatures in the soil. When adults are picked up in the net, applications should be made to target the larvae as eggs hatch. No aerial applications are permitted. Irrigate both before and after application.
Altacor should have good residual and rainfastness, if you are concerned about sprays going out in this unstable weather pattern that we currently find ourselves. 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.
Some folks have inquired about mixing Bravo and Altacor. There is likely no issue with the physical mixing of the two pesticides. However, efficacy may be compromised and we have no data to support this one way or the other. According to Syngenta representatives, when you mix a product with a spreader sticker, like Bravo, with a product that is locally systemic, like Altacor, the locally systemic product may get tied up with the spreader sticker and not work as well. Syngenta folks have seen this with Bravo and other products like Altacor. The only way to get around this is to add a penetrant surfactant and phytotoxicity may become an issue. If you choose to mix these products, don’t mix any more than you will need as these products do not like to sit together for a long time (may be some settling out). If you opt to separate the sprays, apply Altacor first (allow it to penetrate) and then apply the Bravo.
Dodder is starting to show up in good quantity on some bogs. There are not many options left at this point. If the dodder is attached to weeds that are susceptible to Callisto, you can try a Callisto application. If the dodder is mainly attached to cranberry, Callisto will probably not give you the control you are looking for. It is probably past the window for QuinStar if the dodder is already well attached, but if it is not, you could get some control. Now is the good window to use QuinStar for yellow loosestrife control. If you would like to try the hand-held flame cultivators for dodder control (they work well but take time to treat), call Katie at x27 to see if ours are available for loan. The open flame cultivator can be purchased locally (e.g., Home Depot), for about $50. The infrared models are more money and must be ordered over the internet. There are pros and cons to each type and we can talk to you about that if you are interested.
Ocean Spray fresh fruit export growers cannot apply chlorothalonil (Bravo) after July 15. All other types of delivery to OS can receive chlorothalonil applications up to July 25. Folks delivering to Decas cannot use chlorothalonil after July 25. Be sure to confirm with your handler if you have any questions about pesticide use. QuinStar and Poast have 60-day PHIs, so this may be getting close if you are harvesting early September.
Things seem fairly quiet so far. State Bog is 60-80% IN bloom. The Stevens at Rocky Pond Bog in Miles Standish are 5% out-of-bloom. At State Bog, the Ben Lears were 25% out-of-bloom and the Early Blacks were 13% out-of-bloom mid-week. For new hybrids and some early cultivars, recommended spraying for cranberry fruitworm control is at or close to 50% out-of-bloom so you should be collecting data now so you don't miss 50% out-of-bloom. It is time to fertilize with your bloom time application. If you are using sulfur for pH remediation, make sure you are applying when the bogs will be dry. Puddling and sulfur will injure vines.
You may need to be checking early varieties and hybrid varieties soon for %out-of-bloom. Bloom is moving quickly in some areas. It is always good to get 2 %oob counts BEFORE you hit 50%, just to improve your estimate. Some growers may be spraying for fruitworm control by the end of next week. Late water Howes are very behind and barely at bloom yet. It is too late to be spraying for weevil (unless you have LW Howes). Honeybees should be out there working as the weather has been very nice. Bloom time fertilizer applications can go out now. Be careful if hot weather comes if you are usually adjuvants in your mixes. This is especially true for crop oil concentrates. Indar and Abound combinations are good for second fruit rot sprays but remember the 2-week holding time for Abound. It's Frank's last week. Good luck in retirement, Frank!!
Just a short message this week. Bloom is coming on strong this past week. It is absolutely the time to be putting out first fungicide. The weather has not been cooperative, so if you haven't yet sprayed, do it as soon as you have a chance. The window for controlling early season insects is closing unless you have really high numbers. We have had reports of 14 spag larvae and 20 weevils. 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. Pinheads have been noted especially on the new hybrids.
This is the week of spag. There is, however, no easy answer!
Many growers have reported finding Sparganothis larvae in their sweep nets this week. Small, medium, and large larvae have all been reported, as well as the beginning of flight in the pheromone traps (that should be up by now). A few growers reported higher counts of larvae, but most reports were right at or under threshold. Perhaps Avaunt took out all the other caterpillars and now all we find is Spag. It DOES appear to be higher than normal reports. Pheromone trap numbers will go up for the next 3-4 weeks before they start going down! The eggs take 9-12 days to hatch.
The only choices to manage Sparganothis fruitworm are Intrepid, Altacor and Delegate. Intrepid and Altacor will not kill large larvae. They need to be eaten and are best timed against eggs and small larvae. They require good chemigation systems and likely anything over 6-8 minutes will be too watered down to be effective. Several days of good weather are also necessary to maximize effectiveness. Delegate is more likely to take out the medium or larger larvae. We have gotten a few reports of Delegate failures; spag numbers increasing after a spray. Remember, Sparganothis are particularly hard to manage as they are squirrely, web-up and resistant to all organophosphates. Intrepid added to Bravo for first fungicide will help for a few weeks and Altacor for first fruitworm should also impact any spag that are out there.
Bogside Workshop Friday June 21 8:30-10 AM at the Cranberry Station. Katie Ghantous and Hilary Sandler will demonstrate how to use hand-held flame cultivation devices to control weeds. We will be demonstrating a 'mini cannon'sprayer that can be mounted on an ATV, golf cart, or back of a pickup and sprays about 30 feet. Peter Jeranyama will cover irrigation issues, Carolyn DeMoranville will cover fertilizer use, and Frank Caruso will discuss disease management. This will be Frank's last event with us prior to his retirement at the end of the month!
Many growers have been treating with Avaunt over the past few weeks for winter moth or weevil. We learned that gypsy moth sometimes gets through Avaunt, similar to spag getting through. One site had false army, blossom, weevil, bhf on a few pieces plus some spag too with all at, or close to, threshold. Another grower found spanworms in numbers greater than 50 in a sweep net in one case, along with weevil and cutworms. A grower in Rochester had gypsy moth, winter moth and brown spanworm. Another found spag only starting this week, and not just small ones. One grower had cutworms that made it through a long rinse time (end of line) of Delegate. We had weevil at Rocky Pond and sprayed on 5/18 and checked midweek with no return. State Bog had low counts of winter moth and weevil. On a late water bog, a grower reported high weevil and mid-range spanworm counts.
Insect populations continue to be low. However, now is the time to sweep!
Winter moth larvae are easily seen in sweep nets at this time. Populations are not nearly as high as expected this year, but it would be wise to check your own bog. Small gypsy moth, false army worm and even black-headed fireworm have been reported on bogs.
Cranberry weevil are active at this point and some pockets over threshold (4.5/25 sweeps) have been found. Remember, grey weevils found in the sweeps should not be counted as they are not a cranberry pest. Avaunt is a good choice if you have both winter moth or other larvae and weevil. If weevil is not in the mix, Delegate is a good choice for the worm pests, as is Intrepid.
Dodder seedlings are germinated everywhere, we are reaching the end of the window for pre-emergence sprays for dodder. Quinstar is now fully registered for both pre- and post-emergence control of dodder. Many handler restrictions are in place for this compound, so make sure of your handler's requirements before using. Also note that the allowed MAXIMUM RATE on the label is 8 oz. per acre per application with a maximum of two applications [the old Section 8 label allowed up to 12 oz. per application - the new label does NOT].
The window for pre-emergence management of other weeds is over. If the weeds are up, time early post-emergence Callisto applications in the next two weeks or so. This material requires 4 hours to be rain fast.
Since we have reached bud break, we reaching the end of the window for fungicide treatments for upright dieback If you had this disease in 2012, consider an application of fungicide following the recommendations in the Chart Book.
Winter moth larvae were picked up in sweeps last week. There is only a small window of opportunity to get out and sweep this week before the poor weather conditions come in, so try to get out there to see if winter moth is on your bog. Growers were picking up averages of 8-10 larvae last week. They are very small but you should be able to see them. At this size, it is hard to tell if they are WM, black-headed fireworm or Spag, but most likely, they are WM. Avaunt is a good choice along with Delegate and Intrepid.
Dodder seedlings have been reported inland over the weekend (May 4). Scout in the duff layer for emerging seedlings; you do not need to dig into the soil to find the seedlings. Plan herbicide treatments for about 2 weeks after early seedling emergence. Day-old seedlings were noted in Onset on May 8. Photo below shows single dodder seedling (probably several days old) on duff layer.
UMass Cranberry Station • 1 State Bog Road, PO Box 569, East Wareham, MA 02538 • email@example.com • 508-295-2212
The UMass Cranberry Station is part of The College of Natural Sciences.