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IPM Message 2005
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In Frank's travels, he has encountered very little fruit rot, so the "very good" keeping quality forecast seems to holding up. He has noticed significant amounts of cranberry fruitworm injury. It is critical to keep irrigating to support fruit sizing and reduce vine stress until we get some rainfall. Fruit quality will start to suffer in vines that are in a prolonged state of stress.
We will be having a meeting on Tuesday September 6 at 3 PM to discuss issues and get input from you concerning the renovation at State Bog. We plan to renovate in the fall of 2006. We are very excited about the proposition and want to get growers' input. Please see the August newsletter (Jen Friedrich's article on page 3) for more info.
The IPM message will now be updated on an "as needed" basis or at least once every two months. Continue to check the home page for announcements of new information posted to this page.
Reports of concerns have been few from the entomology lab this past week. Admire applications are going out for control of grub pests. If you try Admire, please contact the Ent Lab and let them know if it worked for you. We do not have any specific control data and at this point, are dependent on field observations. There are a few indications that a third generation of BHF may be around. Fruit inspection for cranberry fruitworm will be winding down in the next week or two.
Remember Poast has a 60-day PHI and Stinger has a 50-day PHI.
News on the disease front has also been quiet. Now is the time to be putting out bud set fertilizer applications if that is part of your program. The CCCGA Annual meeting is scheduled for Tuesday August 16. The last IPM message for the 2005 summer season will be uploaded by Friday August 19.
Now is the time to be thinking about using Admire if you have scarab grub infestations. Target oriental beetle immatures with a drench treatment. Admire has a 30-day PHI. Newly hatched grubs are most vulnerable and best results are achieved when the compound is present just prior to egg hatch. Monitor beetle flight activity with pheromone traps to know when egg hatch occurs. Treatments typically go out late July through early August. Admire is very toxic to bees; make sure they are not around if you are using this product. If you have further questions about using Admire on grubs, call the entomology lab at ext 20.
CFW monitoring is still on-going and people are still finding eggs. Some growers have put out 3 or 4 sprays to try to manage CFW. It is probably too late to be chasing BHF though depending on daylength and weather, we could see another generation. Spag managment is also happening now. Intrepid is a good choice but it does have Zone II restrictions.
If you are using Stinger for wild bean control or other sensitive weeds, use the lowest effective dose. Wild bean, in particular, is very sensitive to Stinger. When you use the lowest effective dose, the chances of causing vine injury are also reduced. If there are no vines in the infested area, you can use a higher amount. With severe infestations, you will likely have to treat again next year anyway. Remember, Stinger has a 50-day PHI.
I continue to receive calls concerning use of Simple Green for dodder control. Please see July 15 message for more information. I would encourage growers to apply sooner rather than later as once dodder flowers and sets seed, it will dieback on its own. The key is to try to get it before it sets any seed. Several growers have called to indicate that Kerb did not seem to do as good a job for them this year. I would have to speculate that this was a timing issue more than a resistance concern (many growers still report good control). If you have any thoughts on the matter, please feel free to call or email me at firstname.lastname@example.org.
Cranberry FW moths have been trapped in high numbers in the surrounding areas of active bogs. Growers should continue to be vigilant in their fruit inspection and spray programs. Brown spanworm and black headed fireworm should be less of a concern now. CB weevil numbers are up and you may want to consider scouting for weevil. Also, cranberry flea beetle may be coming onto the scene soon and netting will pick those up, too. If you are targeting soil insects with Admire, your application window is approaching. Apply postbloom when bees are not present during late July and early August. Admire has a 30-day PHI.
Frank reports that things look pretty good on the disease front and no major concerns at this time.
I have been receiving calls about using Simple Green for dodder control. We do not have a lot of experience to be able to answer and describe all of the parameters that would help this compound give the best dodder control. However, here is my current thought on the subject. Use a 20% solution (about 25 oz or 3 cups per gallon). Spray within the next 2 weeks while dodder is still growing and has not yet set flowers or seed. In our study, we sprayed once per week for 4 weeks. This is too much labor and time for most growers' situations. I have heard of growers who did one application and were happy with the results. Even so, results have been variable. I am conducting a trial this year to evaluate single vs multiple applications. I think you may have better success to apply the SG if the dodder is not already stressed. Since the weather has been so hot, perhaps consider irrigating, allow the vines to dry and then apply the SG. As I said, we do not have alot of experience with many different situations. So, if you try SG, please send me an email email@example.com or call to let me know how you used it and how happy you were with the results.
Things are fairly status quo for cranberry fruitworm, BHF, and weevil as reported last week. Continue to sample fruit for fruitworm eggs to determine if additional cranberry fruitworm sprays should be applied. Poast can still be applied for control of grasses but it has a 60-day PHI and cannot be chemigated. You can apply it aerially or as a spot-treatment. Since crop oil concentrate is added with Poast, be very careful if blooms are around and if the weather is hot (as it has been). You will cause injury to the flowers.
Things have not changed too much since the last message. The most critical thing now is to be controlling cranberry fruitworm. First sprays are out for many growers. Some growers are still chasing BHF and it will cause serious damage. It is likely that multiple sprays of Intrepid will be needed to do the job. The overall recommendation for CB weevil is to continue to sweep for this insect even during bloom. The small amount of damage that you may do while sweeping is very small compared to the damage that the second generation of weevils will do to the crop and the vine.
BHF larvae are doing some serious damage to young fruit and leaves. Webbing and feeding damage can be seen on affected uprights. Counts as high as 60 larvae per set have been reported in areas where controls failed. Diazinon and Intrepid are good choices at this point.
Cranberry fruitworm eggs have been found, especially on Early Black and Ben Lears. Out-of-bloom is very variable so you must check your own bog very thoroughly to get a good estimate. First fruitworm sprays are very critical this year. You should consider spraying sooner than the Chart Book recommendations especially for large fruited, early ripening varieties (Stevens, Ben Lear). If you are in doubt as to when to spray, collect some fruit and inspect for eggs. If you find unhatched viable eggs, you should consider shortening the spray window.
CB weevil second generation are out. But, remember, Avaunt cannot be used!
Vines are still running behind and this will affect fertilizer and fungicide schedules. First fungicides are going out on State Bog at the end of this week. If you are doing 3 applications, start at 10% bloom and proceed every 10-14 days. If doing 2 applications, start at 60% bloom and at 10-14 days. If doing only 1 application, spray at 85-90% open bloom. If you need to irrigate and spray around the same time, irrigate first, allow the vines to dry and then apply the fungicide. This will allow the fungicide to adhere properly to the leaf and fruit surface (minimizes wash-off potential).
Both Abound and Bravo are available for fairy ring control.
Avaunt is no longer being sold, but you can use it up to June 30. If you are in a Zone 2, you can use Actara. Be sure to get your letter from Marty (ext.20). Weevils are out and drilling away, but numbers are not as high as last year. Highs that have been reported to us have been around 30 weevils. Brown spanworm is out and hatching. Look for thin thread-like larvae on the edge of your net. BHF is flying and larvae can feed during bloom. Intrepid is a good option here. Cranberry fruitworm moths are also out. We caught 50 adults in a night here at State Bog. Since the vines are delayed, the moths are just waiting to lay their eggs as soon as something acceptable is available. Spag are showing up in all stages. Some growers are still finding larvae while other growers are reporting moths flying.
We think we may be seeing some evidence of winter moth injury from earlier in the year. We collected some vines where the bud was obviously chewed at but not fully consumed. Lateral buds were present on many of the affected vines.
Sparganothis larvae have been picked up in sweeps this past week with most reported numbers in the range of 1-2 larvae per set. Weevil populations have been variable and sprays of Avaunt have been going out to control weevil. It is still undetermined if weevil populations have already peaked or are still increasing so be sure to keep monitoring if weevils have been an issue for you in the past. BHF seems to be going to pupation; be sure to have your traps out. Folks have been calling about tent caterpillar. They have been very prevalent in the woods, but Annie feels that they shouldn't been a problem on the bogs. Please call the Ent lab (ext 45) if you have further questions.
Kerb can only be applied until June 15. Bloom seems to be moving along slowly especially in the native varieties. We have not really heard of many reports of even scattered bloom yet. We are still a bit behind, but with the warm weather, you may be needing to apply your first fungicide spray perhaps by late next week.
We will be holding a grower workshop to discuss pest management issues of the day on June 21 from 10-noon at the library.
The nice weather this week has allowed many people to put out sprays to control BHF, weevil, cutworms and dodder. High counts of BHF have been picked up in some situations. They are getting somewhat large, 7-8 mm, and the ent lab believes we are entering the last week or so before they pupate. So, if you need to spray, do it soon. People are spraying for weevil, but in many cases, weevil are still moving onto the bog. The Ent lab recommends trying to focus control efforts on the spring generation whenever possible. In an earlier message, I wrote that we thought the threshold for winter moth was 4-5; that is not what we presently believe. The action threshold for winter moth is currently estimated to be the same as spanworms, around 18 larvae per sweep set.
Due to the potential increase in demand for Bravo-type products from other commodities, Frank is recommending that you may want to purchase your Bravo supplies sooner rather than later. Soybean growers may be needing more than their usual share this year, depending on how they opt to handle their managment of asian soybean rust disease. Due to the very good to excellent KQF, fungicides rates and numbers of applications can be reduced this year. However, 3 applications should be considered for bogs that had above average levels of fruit rot last 2 years.
We will be holding a grower workshop to discuss pest management issues of the day on June 21 from 10-noon at the library. No contact hours will be offered, but it is an oppportunity to have an informative question and answer session with Station personnel and other growers.
Under the permit of the Section 18, Kerb can be legally applied until June 15, 2005. Grower reporting forms are due by November 30, 2005. A few questions have been raised concerning my recommendations and the CCCGA Growers Advisory for Kerb. The advisory recommends minimizing the rinse-out time and I have been recommending application of 0.1-0.2 inches (if no rain is expected). These are not in conflict. CCCGA is advising growers to minimize the chance of run-off with Kerb. So you should still run your system long enough to get the herbicide off the vines and into the soil, but do not run any longer than necessary.
The past week of rain has certainly slowed everything down and has hampered alot of field work activites and scouting. This has already been one of the coldest Mays on record here in East Wareham. Frank reports that the Keeping Quality Forecast will have 7 of 16 points, making this the 3rd year in a row with very good to excellent KQ. Even with the rain, applications of Aliette and Ridomil should be fine. Growers with blueberries, strawberries, apples, etc may be feeling the pinch with lowered pollination due to the bad weather.
When we have been able to scout, we have picked up gypsy moths, winter moths, and first instar false armyworm. We know BHF is out there, but larvae may be very hard to pick up. It may be hard to see the damage and the webbing may be hard to see since there is very little new growth. Be vigilant. Weevil populations seem to be low, but if we ever get some warm dry weather, numbers may increase quickly. Cankerworm is another geometrid or looper that has also been seen. Seat-of-the-pants thresholds for winter moth and cankerworm are similar to spanworms, an average of 18 larvae per sweep.
Pheromone traps for BHF, Spag and girdler should be out ASAP. This is especially important if you are planning to use Intrepid or Confirm for BHF. The trap helps you identify the first evidence of moth flight. You should spray 3 weeks after first flight (the biofix).
Dodder has been slow to come up, but growers are reporting that they are seeing sprouts on the bog this week. Kerb can used until June 15 and if dodder is just showing up on your bog, applications made shortly after Memorial Day should be very timely. We have received notice that EPA has approved a postemergence biocontrol for dodder. The product is called Smolder. It is NOT approved for use in MA yet and likely will not be available for the 2005 season. However, Frank and I will be working to file the paperwork to get the product registered in MA for next year, so keep posted.
Avaunt is available through Section 18 permit for a short period, from now until June 30th only. Two applications are permitted up to 6 oz/A per application, not to exceed 12 oz. Allow 7 days between applications. Should the weather get warm and sunny, expect weevil populations to build quickly. Weevil numbers are building on blueberries and we expect them to move to cranberries soon. We have issued a special newsletter relating to Avaunt. Click here for the PDF. Actara CANNOT be used in Zone 2 areas between now and June 30th (since we have Avaunt).
Black headed fireworm, gypsy moths and green spanworms have been picked up in sweep sets during the past week. The gypsies are very small, 1/8", so our general feeling is that (coupled with the cool weather) you should consider waiting until next week to spray. We would recommend sweeping again next week and see how things look. Some growers (especially in Zone 2 where Intrepid cannot be used) are thinking about using Orthene or Diazinon for GM control.
Some growers have been putting out their Kerb applications. Afew reports of dodder on bogs have come in, but not many. You should look in your warm spots and off-loading areas for the very small, thin yellow seedlings. Remember Kerb can be used until June 15 if needed.
Things on the bog have been progressing rather slowly since the spring has been quite cool. However, in the past day or so, Blackheaded Fireworm (BHF) and winter moth larvae have been picked up in sweep sets. Take care not to confuse these caterpillars. BHF has a distinctly black head and kind of yellowish body with 4 sets of legs in the rear. Winter moth (esp. early larvae) can also have a black head, but this becomes a bit browner as they get older. Winter moth larvae are greenish and exhibit a looping behavior and have 1 set of legs in the back like spanworms. Their front 3 pairs of legs look very wispy like BHF. Our seat-of-the-pants action threshold for winter moth is 4-5, but this is just a guess. Green spanworm have also been picked up. If you have not starting scouting yet, you should get out there ASAP, especially if the weather warms.
Dodder has emerged in our experiments on 9 May (located off-bog and tend to be warmer). Most growers I have talked to have not yet seen dodder ON bog. Dodder has been seen in trash piles (again, warmer locations off-bog). If you are in a Zone 2 and want to apply Kerb, you must have documentation that Casoron has failed for you in the past. Otherwise, you must use Casoron in 2005. Please see my letter on Zone 2. Some growers are planning to apply Kerb next week, but this may be a bit early. If you can hold off until the next week (or about 10 -14 days after you see the first germination), that is a better target window.
If you have further questions about Kerb and Zone 2 applications, please call me at ext. 21.
UMass Cranberry Station • 1 State Bog Road, PO Box 569, East Wareham, MA 02538 • firstname.lastname@example.org • 508-295-2212
The UMass Cranberry Station is part of The College of Natural Sciences.