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IPM Message 2006

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AUGUST 18

Findings are similar to last week's message. There are spots of Spag infestations, but it is low industry-wide. Most folks got good control of the first generation with the early Spintor sprays. In general, cranberry fruitworm pressure seems low. Flea beetles are out there and there are a few hot spots (counts exceeding 50 per sweep) that required treatment. Applications of Sevin for fruitworm are keeping flea beetle in check. Clean Sweep reported a third generation of blackheaded fireworm on Nantucket. They also report seeing some upright dieback. This disease can be exacerbated by drought conditions. If you suspect that you have upright dieback, collect some vines from the damaged areas and bring them into Frank in the Plant Pathology lab.

The CCCGA Summer meeting will be held at Betty's Neck Farm (not the Cranberry Station facility as in years past) on Tuesday August 22. Contact the CCCGA for more information.

This will be the last weekly IPM message of the 2006 season. If other issues arise that need attention, I will list a link on the home page. Happy Harvesting!

AUGUST 11

We have seen flea beetle damage on several bogs in the industry. Sevin will work against flea beetle. You should do sweep counts before deciding to spray. We recommend reaching an action threshold of 15-20 beetles per sweep set before spraying to control them. If you do decide to treat, you should continuing sweeping to determine the infestation levels as repeat applications may be necessary.

We have been finding live, unhatched, orange-lined eggs in berry samples. We encourage you to continue sampling fruit to determine cranberry fruitworm sprays for at least another week. The entomology lab reports that they noticed an increase in fruitworm moth flight last week, so there is still activity out there.

If you plan to do tissue test, collect your samples from mid-August through mid-September. You can get your samples analyzed locally or send them off to UMass for analysis. Samples should contain no more than the top 2 inches of growth (no roots, soil, runners, or fruit). Collect tissue from vegetative and flowering uprights. You typically need about 1 cup of vine tissue. Do not collect samples when the vines are wet and do not send the samples in plastic ziploc bags. Always request nitrogen determinations when you submit your samples.

The CCCGA Summer meeting will be held at Betty's Neck Farm (not the Cranberry Station facility as in years past) on Tuesday August 22. Contact the CCCGA for more information. There will be one more IPM message posted by the end of the month before we suspend for the scouting season.

JULY 29

Reports have come in of weevil counts exceeding threshold in some areas (around 20). Some growers report that they feel cranberry fruitworm pressure seems low this year. Consultants report 1-3% infestation on many bogs with approximately 3-4 sprays out. Fruit inspection should continue at least until mid-August.

Spag larvae are being picked up in sweep nets. Moth counts in the traps have dropped way down in the past week. Intrepid can be a good choice for Spag as long as your bogs are not in a Zone II. Black headed fireworm larve have been seen inside berries (just a few). Flea beetle counts (around 15 per sweep) were noted on a few bogs.

Irrigation continues to be key as we head into another hot spell. It is always better to keep your plants well watered all the way along rather than trying to stretch the intervals and then play catch up. The water demands of the fruit are high this time of year.

Under a special local needs registration (24C) approved by MDAR, Diazinon 14G made by Wilbur Ellis can be used now and for the next 2 growing seasons to manage girdler. A supplemental label is available at the vendors and at the cranberry station and is necessary if you wish to apply the material.

Broadcast  21 lbs per acre or spot treat as necessary.  Granules should fall through the vines to the soil surface.  Irrigate immediately after application to insure that diazinon has contact with larvae living in the leaf litter. Only one application per season - mid to late July. Do not apply to ditch banks or ditch water.Ground application only, no chemigation or aerial application allowed. Hold water for 7 days. 5 Day REI.

JULY 21

Things have seemed relatively quiet across the industry this week, with respect to pest problems. Fruit inspection for viable, unhatched cranberry fruitworm eggs continues. In some cases, growers have already made 4 fruitworm sprays, though many others have made fewer than 4. Cranberry weevils are still being found, though generally in numbers below threshold. A second Spag application has gone out on a few bogs after a few larvae were picked up in sweep nets.

Certainly, the weather has been a big issue with very hot conditions early in the week. It is important to keep your vines well watered all the way along (and thus prior to the onset of very taxing periods of evapotranspiration). The water demand of the plant during this time of year is the highest compared to other times during the growing season. The "1 inch per week" rule will not suffice here; vines probably need closer to 2" per week during fruit set.

We have a job opening at the station for our Farm Manager position. If you are interested, please contact Debbie at ext 10 or Carolyn at ext 25 or click on the link above. The deadline for applications is July 28.

JULY 14

Clean Sweep Consulting reports that they have seen high infestations of southern red mite. This is certainly a pest that has been under the radar screen for many years. Look for red smears near the top of your sweep net. Nexter (same ingredient as Pyramite) or Trilogy can be used to manage SRM. Clean Sweep and we have been seeing a lot of stressed vines, often showing up as yellow vine syndrome. Again, we cannot say the exact cause of YVS but it seems to be associated with either too little or too much water. Consider installing a water level float to help you manage your water levels. These can be purchase at the station for $15. Call Krystal at extension 42 for more information.

Second generation cranberry weevil is out. Actara can be used to manage CB weevil. This is a Zone II restricted material. CB fruitworm moth flights are declining and most people are in the process of applying their second spray. Start inspecting fruit 1 week after application.

JUNE 29

Reports from Clean Sweep Consulting early in the week indicated that brown spanworm is hatching. They have picked up numbers under threshold, normally around 2-6 per set. CB weevil have been swept in very low numbers. Sparganothis larvae are pupating and many adults are flying. Bloom was moving along, but may have slowed a bit in the past few days. One Ben Lear piece in Lakeville was at 37% out of bloom last weekend! So some bogs are very advanced. You should be checking to see what your % out-of-bloom is so you can get at least one date BEFORE 50%; two are preferred. See the Chart Book, page 13 for details on how to calculate % oob. Timing of the first spray is critical. Spray 3-5 days after 50% oob for Stevens, 5-7 days for Ben Lear and 7-9 days for Early Black and Howes.

Be sure to sample fruit RANDOMLY when looking for CB fruitworm eggs. You do not want to skew your sampling to pick fruit that the females prefer (eg, enlarging pinheads, or fruit high in the canopy). Pick 50 fruit per acre with a minimum of 200 fruit per management piece. If you need to treat: Intrepid by chemigation is not a good choice for cranberry fruitworm since the larvae do not eat enough treated tissue. Results have been better with boom sprayers at 20 gal/A. Diazinon is probably the best choice, followed by Sevin. Please sure to check your diazinon label. If you have new product, you will be limited to 3 sprays. Lorsban is certainly permissible but it is a heavy hitter and kills beneficials.

Most folks fared better with the last bout of heavy rains; few bogs were actually submerged for any length of time. However, vines from a bog that went under had damaged tips and lost most of their bloom. Water and air temperatures were warmer during this rain event compared to the last one and the tissues were more susceptible for this rain storm, so damage was sustained much more easily.

JUNE 21

First fungicides should be going out (or already applied) if you are planning on a 3-spray schedule. We attempted to apply our first spray on Friday June 16, but the weather was unstable for several days. If you are following a 2-spray program, apply around 25% open bloom. The first spray is very important for good control.

A bit of a change for BHF control from notes in the Chart Book. Annie is recommending applications 10 days after peak flight (instead of the 3 weeks mentioned in the Chart Book). BHF development moves along very quickly (~2 weeks from egg laying to larval development). So keep this smaller window in mind if using Intrepid for BHF control. Intrepid is a good choice for BHF (if not in a Zone 2). Spag moths are starting to fly; they are day-active, so you will see the moths when you are sweeping or otherwise out on the bog. Spag populations typically peak around the first week of July. Spintor, Intrepid, and Confirm are the good choices for Spag. Remember Intrepid cannot be used in Zone 2 areas. You are limited to 4 applications of Intrepid per season. CB fruitworm moths are also starting fly now. Manage CBFW populations by calculating 50% out-of-bloom (more on that next week).

Remember, the new labels for Diazinon permit only 3 applications (as opposed to the 4-6 previously permitted). Be sure to carefully read the label of the Diazinon product you are using so you make sure you are in compliance.

Continue to sweep for cranberry weevil and brown spanworm through bloom; you can still pick up damaging populations at this time.

We are offering an additional workshop on Monday July 10 for 3 contact hours. Please see the calendar for more info. The IPM message will be updated by next Friday June30.

JUNE 13

I want to clarify that IT IS ILLEGAL to use Callisto on cranberries in Massachusetts. Although it is labeled for use in MA for other commodities (such as corn), cranberries are NOT currently on the label in this state. We anticipate that we might have a full label in 2007. Until then, please DO NOT use Callisto on your cranberry farms.

Some of the confusion likely stems from the fact that Washington State cranberry industry received an emergency exemption to use Callisto. They received the permit to use the herbicide against certain serious weeds (primarily for silverleaf, the common name for a Potentilla species that is not a problem in MA) for which they have no other control option. Some of you probably heard that a Section 18 was granted for the use of Callisto and that is true; it is just ONLY applicable for the Washington cranberry industry.

To be granted a Section 18 permit, one must demonstrate that there are no other viable control options AND without this particular pesticide, an economic emergency would occur in the industry. In our situation, Callisto is effective in controlling nut sedge (primarily), other sedges, and probably some rushes and other broadleaf weeds. At present however, we have other materials available that will control these weeds. As a result, I could not legitimately demonstrate that we would have an economic crisis if we did not get to use Callisto prior to its full registration.

Again, it is illegal to use Callisto on cranberries in MA. If you have any other questions about Callisto, please feel free to call me.

This update was posted on Tuesday and scouting reports had not yet come in. I will update again next Tuesday and then again on Friday the 23rd, returning to my usual Friday updates.

JUNE 9

Not many people were able to get out to scout this week due to the heavy rains. Many locations received 6-8 inches of rain Tues-Wed. The biggest concern was that some beds were under water for a period of time. Being that most of the water drained off within 48 hr, we do not expect much in the way of damage. It was certainly helpful that water temperatures were cool. Frank recommends staying the course and managing the bloom according to your typical fungicide program. However, if any flooded portion is prone to Phytophthora root rot, you should consider applications of Ridomil, Aliette or Phostrol. Please let us know if you notice unusual symptoms that you think might be related to the flooding situation.

We will be hosting a workshop on Wed June 21 from 10-noon at the station. We plan to discuss cranberry fruitworm managment and fertilizer issues. Feel free to bring your questions or concerns to the meeting. 1 contact hr will be offered.

JUNE 2

Reports from Clean Sweep Consulting indicate that tent caterpillar has been showing up in peoples' nets. As far as we know, tent caterpillars are not eating cranberries. However, if you have seen damage, please let us know. Many folks thought the TC were gypsy moth larvae. GM caterpillars are very hairy all over whereas TC have most of their hairs along the bottom of their body. Also, GM are still somewhat small now and the TC are 2 inches or more.

Spag has been swept in numbers usually around 2-3 but have been as high as 6. Traps should be set out for Spag, Blackheaded fireworm and girdler. BHF is probably getting too big to control at this point and adults will be out soon. If you still have small larvae, you may want to wait until after this rainy period and then spray Spintor. Cranberry weevil have been in counts around 6-10 but low 20's have also been netted. Remember Actara is the best choice for CB weevil control; Avaunt cannot be used.

Untreated green spanworms are causing damage. But remember the action threshold is 18 larvae per sweep set. Bogs inland (Lakeville as the like) are approaching early hook. Be sure that you have your bees lined up for bloom.

MAY 25

Much of the information today comes via Clean Sweep Consulting and conversations with growers at our workshop on the 24th. Gypsy moth counts have been very high in some areas (people stopped counting at 50 per sweep set). However, Gypsy moth counts went down when a spray was applied. However, some areas are still above threshold. Folks are planning to sweep again after the application and may consider another application if numbers are still high. Gypsy moth, cutworm, blossom worm larvae are all added together to determine if your infestation has exceeded the action threshold of 4.5 larvae per sweep set.

Sparganothis fruitworm larvae are being picked up in the net as well. Some bogs are close to averaging 1.0 per set - the larvae are small. Clean Sweep has been seeing fireworm larvae of varying size indicating that the hatch has staggered. Larvae vary in size from newly hatched to 1/3". We have picked up BHF and Sparganothis larvae on State Bog and Rocky Pond and have opted to spray Sevin for control.

Green spanworm has been reported to be in numbers exceeding 25 per sweep. Remember the action threshold for spanworms is 18 larvae. Significant damage has been seen in untreated areas.

Weevil counts were low early in the week, likely due to the windy and very cold conditions. However, later in the week, especially in the Carver area, weevils are out in high numbers (11-16 per set). Actara at 2 oz per acre in systems that perform under 8 minutes is very effective against weevil. You may need to treat again. Avaunt cannot be used this year.

Our next workshop is planned for Wed June 21 from 10 AM - Noon , focusing on cranberry fruitworm and fertilizers and any other issues of the day. There is no need to pre-register.

MAY 19

The bogs are drying out now and folks have been out sweep netting. We have found blossomworms in fairly high numbers along with gypsy moths. The combined action threshold for cutworms is 4.5 larvae per 25 sweeps. Tent caterpillars are obvious in the crotches of trees, but you should not be concerned about these for cranberry. We have also picked up BHF larvae in numbers high enough to trigger a spray. Remember Intrepid cannot be used on bogs in Zone 2 areas.

Dodder is emerging on many growers’ bogs. We do not have specific research information to totally back up the interval between sighting of first emergence and applying Kerb. However, other data we have shows peak emergence occurs about 14-21 days after first emergence. Of course, go with the interval that has worked well for you. If you are uncertain, I would recommend a Kerb application about 10-14 days after 1 st emergence. 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. Please see the chart book for more information.

Our water float and fruit rot workshop on Wed May 24 will begin at 9 AM . We will have a short sweeping demonstration at the end of this workshop since we were not able to do any sweeping at the last workshop (due to wet conditions).

MAY 10

Things on the bog have been progressing rather slowly since May has been quite cool and very wet. It looks like we are in for several days of potential showers and rainy cool weather. You should be ready to scout as soon as the weather breaks to get baseline information. A few BHF, gypsy moth and cutworms have been picked up so far. This kind of weather makes netting for cranberry weevil very difficult.

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.

Dodder has emerged in our experimental pots on 2 May (located in 5-gal buckets off-bog) and I found many germinated seedlings on State Bog on 4 May. 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. Please see the chart book for more information. 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.

We are having a water float and fruit rot workshop on Wed May 24. You need to sign up by 17 May to attend. The cost is $20.

 

 

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