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Massachusetts Berry Notes

Volume 13-- 2001 Berry Notes is written by Sonia Schloemann except where other contributors are noted. Publication is funded in part by the UMass Extension Agroecology Program and grower subscriptions. A text version can be e-mailed to you if you contact Sonia Schloemann. Please cite this source if reprinting information.

Summer Edition 2001 #6 Vol. 13, No. 11 June 29, 2001   Crop Conditions and Pest Summary Strawberry harvest is proceeding well.  Fruit quality is generally very good.  Hot weather will accelerate ripening, so be sure to keep fields well picked to avoid problems with sap beetle.  Irrigation can be used to cool fields during high heat periods.  Keep an eye out for evidence of black vine weevil feeding injury on strawberry leaves.  See last issue of Berry Notes for more about this pest.  Check new plantings for signs of potato leafhopper and/or cyclamen mite.  Early Blueberry varieties are beginning to ripen.  Fruit load is quite variable this year depending on variety and site.  Several farms report problems with Bluecrop (poor set, poor vigor), and Berkeley (shoot and cluster dieback).  Contact me if you are having similar problems.  Blueberry maggot fly is here.  Be sure to set your traps to determine migration into your blueberry planting.  Summer raspberries are post bloom with early varieties (e.g., Reveille) beginning to ripen fruit.  Potato leafhoppers are here in full force.  Keep an eye out on fall bearing varieties for hopper-burn.  Grapes progressed rapidly through bloom to fruit-set in the recent heat.  Post-bloom disease management protocols are inportant.    Grape berry moth larvae are present in vineyards now.  They can be located by looking for prematurely colored fruit.  Potato leafhopper and Japanese beetle are also present in vineyards now.  Check out http://lenewa.netsync.net/public/update.htm for updates from the Lake Erie Regional Grape Program. Meetings   Garden Center Critique and Merchandising Workshop Tuesday, August 7, 2001 10 AM - 3:30 PM Briggs Nursery, Inc., 295 Kelley Blvd. North Attleboro Dave Seavey, University of New Hampshire Extension, will use his Garden Center Critique and Merchandising Guide to lead retailers in a hands-on workshop analyzing marketing practices, scrutinizing their operation through the eyes of their customers, improving efficiencies and developing innovative marketing strategies. Attendees will use the garden center at Briggs Nursery as an example for their critique. The workshop fee is $40. To preregister, contact University of Massachusetts Extension Floriculture Program, Paul Lopes  508-295-2212 ext. 24 or Tina Smith, 413-545-5306. Weather Data The following growing degree day (GDD) and precipitation data was collected for the period, June 21 through June 27, 2001. Soil temperature and phenological indicators were observed on June 27, 2001. This information is intended to be used as a guide for monitoring the developmental stages and planning management strategies of pests in your location. Region/Location Growing Degree Days Soil Temp Accum. Precip   1 Week Gain Total for 2001 (4" depth)   Cape Cod: Barnstable 132 828 75° F 0.50" Eastern:          Hanson 166 875 85° F 1.00"                      Waltham 155 1042 77° F 0.97" Central:        Boylston 152 853 80° F 0.60" Western:       Amherst 139 903 70° F 1.50"          Great Barrington 116 757 65° F 1.35" (Source: UMass Extension Landscape Message #17, June 29, 2001) STATE WEATHER SUMMARY For the Week Ending Sunday, June 24, 2001 Prepared by AWIS, Inc.   AIR           TEMPERATURE    GROWING DEGREE DAYS CUM SINCE MAR 1           BASE-50F  BASE-60F STATION          LO  HI AVG DFN   TOT  DFN  TOT  DFN Ashburnham 58 88 70 +6 678 +220 232 +142 Boston 61 91 74 +5 882 +180 370 +165 Greenfield 51 90 69 +1 690 -1 236 +29 New_Bedford 61 84 73 +5 778 +89 283 +93 Otis_AFB 63 81 73 +8 732 +242 276 +174 Plymouth 58 87 72 +6 728 +199 258 +133 Walpole 61 90 73 +7 840 +257 335 +187 West_Medway 60 92 73 +7 834 +251 329 +181 Westover 59 88 71 +2 862 +39 336 +59 Worcester 55 85 68 +3 733 +208 267 +149 Worthington 50 88 66 +2 556 +98 161 +73 (Source: New England Ag. Statistics Service, New England Weekly Crop Weather Report, Volume 21, No. 8, June 25, 2001) Strawberry   Sap Beetle – Sonia Schloemann, UMass Extension One concern at this time of year is strawberry sap beetle and picnic beetle.  Sap beetles cause hollowed-out cavities on ripe fruit; an injury very similar to slug injury. Adults are small oval beetles about 2mm long and dark brown in color.  They are often hard to see because they drop to the ground when disturbed, but they may be found in the cavities they have chewed out in the fruit.  They are often found when there is ripe or over-ripe fruit in the field.  However, fields with a history of sap beetle infestation can suffer injury very early in the ripening stage.  Sap beetles can move rapidly into ripening strawberry plantings, especially when rainy spells occur during harvest, resulting in the build-up of overripe berries. The best management for this pest is sanitation; keeping the field as free as possible of ripe fruit.  Under severe infestations an insecticide application may be warranted.  Several materials are recommended for managing this insect.  Among them, Brigade™ has a very short harvest interval of 12 hrs.  However this material can be especially devastating on mite predators.  So, watch for a flare-up of two-spotted spider mites if you use this product.  Be aware of any harvest restrictions of materials used.  Always read the label.  Research in Maryland suggests that renovating as soon as possible after harvest can reduce infestation by sap beetle by over 60% in subsequent years. Anthracnose Fruit Rot in Strawberries, Annemiek SchilderMichigan State University Dark, circular sunken areas on strawberries are indicative of anthracnose fruit rot, also called black spot. This disease is usually caused by the fungus Colletotrichum acutatum, but other Colletotrichum species may also be involved. The fungus may also cause petiole and runner infections, flower blight, and anthracnose crown rot. Lately, anthracnose crown rot occurrence appears to be on the increase in Michigan. Flowers and ripening fruit are very susceptible to anthracnose fruit rot. The pathogen can spread rapidly through fruiting fields during rainy, warm periods. Irrigation to help cool down the berries may also contribute to spread and infection. The first symptoms of anthracnose fruit rot are light brown, water-soaked spots on ripening fruit. The spots quickly develop into firm, round lesions, which usually turn dark brown to black and become slightly sunken. Under humid conditions, salmon-colored spore masses cover the lesions. Spore production, spore germination and infection of strawberry fruit are favored by warm, humid weather. This explains why we often see anthracnose fruit rot appearing later in the picking season. Conidia are produced in a slimy matrix and are easily dispersed by splashing rain or by insects, animals or people moving through the field. Infected berries eventually dry up and mummify and can become a source of inoculum for the following season. C. acutatum is known to survive in infected plant material for up to nine months. Anthracnose fruit rot is very difficult to control when environmental conditions are favorable for infection during harvest. Therefore, control measures must begin early in the season. Start out with disease-free planting material. However, it is very difficult to detect the fungus in planting material because it causes latent (invisible) infections. The best approach at this point is to choose a reputable source of planting material and check newly planted fields for symptoms of disease, such as wilting or dying plants, which could be indicative of anthracnose crown rot. The spread of inoculum in the field can be reduced by mulching row middles with straw and using drip irrigation rather than overhead irrigation. Fruit with anthracnose lesions should be promptly removed from the field to reduce inoculum levels, especially early in the harvest season. Anthracnose fruit rot can be partially controlled by applying protective fungicides, such as Captan and Benlate or Topsin-M, from flower bud emergence through harvest. (Source: Fruit Crop Advisory Team Alert, Vol. 16, No. 13, June 26, 2001)   Highbush Blueberry Blueberry Maggot Fly – Sonia Schloemann, UMass Extension Blueberry maggot season is upon us.  Yellow sticky board traps should be set at the edges of the field to monitor migration into the blueberries from woods and hedgerows.   However, these boards attract mainly newly emerged flies that are looking for sources of honeydew on foliage (the flies perceive the yellow color as a ‘super leaf’).  Once the flies are sexually mature and ready to find berries for egg-laying, they are not as strongly attracted to the yellow boards.  Also, many flies spend the first week after emergence outside of the blueberry planting and never show up on the cards.  Therefore, if you have a history of serious damage from BBM, secondary placement of the baited green spheres will help ensure that you know when migration into the planting is happening.  Traps are available from various sources including: Great Lakes IPM, 10220 Church Rd. NE, Vestaburg, MI  48891; 800/235-0285, Fax 517/268-5311, glipm@nethawk.com.   Blueberry Tip Borer -  Sonia Schloemann, UMass Extension Blueberry Tip Borer (Hendecaneura shawiana) - In June, before new growth has begun to harden, some blueberry shoots may begin to wilt, arch over, and become discolored, the leaves turn­ing yellowish with red veins and the stems pur­plish.  This injury, which may be mistaken for primary mummyberry infection, is caused by the tip borer.  The newly hatched worm, tiny and pink, enters the soft stem and bores channels that may extend for 8 or 10" by autumn and result in the destruction of the stem’s fruit-production po­tential in the following year.  Prune out damaged tips as ob­served and burn infected canes.  The standard spray program used for other insect pests normally keeps this pest under control. New Jersey Update – Gary Pavlis, Rutgers University Anthracnose disease has been very scarce so for this year. Continued hot, muggy weather could cause this disease to flare up. Once it starts it is very difficult to control. If you don’t want to gamble on the weather, add three pounds of 80% Captan WP in the insecticide spray. Because Captan has a 4-day re-entry period, many growers have discontinued Captan sprays during harvest and have chose to tolerate the increased Anthracnose. Mummy Berry symptoms were seen in some berries harvested this week. I continue to see canes dying with no leaves present. We have tested these canes for disease and none was found. In most cases, the dead plants are due to a lack of water. Not because they aren’t getting irrigation, but because the roots are enable to take up the water. In one case it was because the soil pH was 6.1, in another case it was because of grub damage, in another case it was due to mealy bug damage. No leaves means root damage, the plant must be pulled out and the roots inspected to determine the cause. I have also seen bushed with individual canes dying in fields. The leaves & fruit are all dried up. This is called flagging. In some cases is was Phomopsis, a few cases were Stem Blight. In both cases the canes must be cut out ASAP before the disease moves down into the crown and kills the entire plant.  (Source: Blueberry Bulletin, Vol. 17, No. 10, June 24, 2001) Brambles   Raspberry Notes from the North Country – Pam Fisher, Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) Harvest is approaching and should begin next week in the earliest areas. Raspberry cane borer has been reported in Michigan and southwestern Ontario. This pest causes tops of primocanes to wilt above the spot where it lays its eggs. Break off infested canes and throw them on the ground. This will prevent the problem from building up to serous levels. Check fall-bearing raspberries now for two-potted spider mites. [The only miticide you can use before harvest is Apollo , which kills mite eggs. It has a 15 days to harvest interval. Do not use Pyramite before harvest on raspberries: it is labeled for post harvest only.] – NOT IN THE U.S. Use mite predators available from various sources.  Call me at 413-545-4347 for sources. Where severe weather occurred this week, watch for fire blight problems on Boyne and K81-6. Leaves will turn black, beginning with the viens, and the the tips of new shoots wilt wilt and droop. There are no sprays for fire blight on raspberry. Infected plantings should be pruned to the ground for one year to reduce the inoculum. Rose Chafers are out active now. These are beige, long-legged beetles that are often found in pairs. A few will cause insignificant damage. High populations can cause defoliation. Rose chafers are very hard to control. Insecticides applied for other insects may affect rose chafers as well, but only for a few days. (Source: Berry Bulletin Agriphone For June 22, 2001) Grapes Winter Injury and Other Maladies in Grapes– Bruce Bordelon, Purdue University Many grape growers in Indiana were dismayed this spring when they observed winter injury on their vines.  Certainly there were some frost problems this spring, both in April and again in mid-may, but the damage we‚ve been seeing is from winter cold, not spring frost.  We had a normal winter and damage this severe was not expected.  It turns out that the situation is common throughout the east.  New York, Ohio, Pennsylvania and Virginia growers have experienced the same problems.  Experts are speculating at the causes, but we‚ll likely never know for sure why so much damage occurred.  In some areas early fall frosts or freezes may be to blame.That is likely the case in much of Indiana where warm and wet conditions kept vines growing vigorously through September.  When freezing temperatures occurred in October, many vines were not well hardened off. We‚ve also seen an unusual amount of incomplete, or inconsistent bud break on many varieties.  In my plots I had vines with 2-3 inch shoots and buds just breaking at the same time.  I thought the late buds would catch up, but they haven‚t and now we have shoots just finishing bloom while others set a crop 2 weeks ago.  These conditions are likely due to incomplete bud development last summer.  I‚d like to think that a situation like this won‚t happen again, but thinking back about the unusual weather this spring has me wondering what kind of weird symptoms we‚ll see next year. (Source: Facts for Fancy Fruit 2001-08, June 20, 2001)   Long Island Grape Update – Alice Wise and Daniel Gilrein, Cornell University Week of June 24: Continuing the trend of extreme weather, it was blazing hot and humid this week. All varieties are in the postbloom stage with Chardonnay berries rapidly sizing up. Hedging and leaf pulling are underway in local vineyards. Fruit Set: At the research vineyard, set was highly variable this year. Chardonnay has too many clusters with too many berries. Thinning fruit will take a while this year. Sauvignon Blanc is variable with some clusters not setting any berries. Tocai Friulano, Muscat Ottonel, Muscat Blanc and Viognier have moderate but not terrific set. In the reds, Cabernet Sauvignon and Cab Franc look decent. The big news is Merlot, where set ranges from poor to moderate. There does not seem to be any consistent pattern except that clone 181 did a lot better than 314. Own-rooted vines also were on the lighter side. Interestingly, there is a high degree of variability even within a single Merlot vine. The later reds such as Petit Verdot, Syrah, Sangiovese and Barbera are a little on the light side but no disasters. Malbec is once again a heartbreaker with poor set.         Why the poor set in Merlot? Merlot is known to periodically have problems with set. Obviously vine imbalance can play a role ñ nutritional imbalance, overcropping the previous year, excessive vegetative growth, etc. More likely in this case, the radical weather this spring is the culprit. Any kind of abnormality at bloom, whether vine or climate-related, can cause disruptions in fruit set. The fertilization process can be undermined if there is a delay in opening of the anthers, inhibition of pollen tube growth, drying of the stigma prior to receiving pollen and so on. Pest Update: A few potato leafhoppers are around, a few Japanese beetles and the usual grape berry moth. No firm reports of thrips. Only a few reports of mites so far this year. No reports of disease problems other than the usual spotty infections of phomopsis. Black rot, phomopsis and downy mildew pressure should be low due to lack of rain this week. No significant rain is currently predicted for the coming week either. Consider our growing season to be one long powdery mildew infection period. Powdery mildew protection is critical now. Researchers in Geneva have found that diffuse powdery mildew infections, those not visible to the naked eye, are implicated in the development of Botrytis bunch rot.         In some varieties such as Chardonnay, there is an extraordinary amount of cluster debris. In Merlot and Syrah, the flower caps have withered and are clinging to the developing berries. All of this means that a bunch closing spray for Botrytis is warranted in susceptible varieties (tight clustered whites and Pinot Noir). Thorough coverage is essential; targeting the spray toward the cluster zone is helpful. Grape pathologist Wayne Wilcox surmises that a Botrytis material in the general tank mix would likely provide protection though it is obviously less efficient than a directed spray. (AW) Thrips: Scouting should start soon for thrips. We suspect the species to be western flower thrips though formal ID has not been done. Look for stunted chlorotic shoots and leaves with necrotic flecking, scarring or distortion. Fruit can also be scarred but probably this has little or no effect on yield or fruit quality. To detect thrips, tap the suspect shoot or foliage over a white board or paper. Thrips (this is the singular and plural form) are white to yellowish brown, 0.8 to 1 mm long, and have antennae and a segmented body. They are very hard to see with the naked eye. A good hands lens (better yet a microscope) is necessary. As with PLH, there are no thresholds for this pest. Thrips populations tend to peak (past experience here ñ latter part of June) then decline. Make your decision while the population is on the upswing meaning that repeated scouting is necessary to judge if populations are building. The only material labeled for control of thrips on grapes is JMS Stylet Oil. Its potential for control is unclear. In a greenhouse trial at the LIHREC, CCE entomologist Dan Gilrein found that a 2% horticultural oil did reduce numbers on grape foliage. To have an impact, coverage must be absolutely excellent and a 2nd spray should be applied 7 days later. In the same greenhouse trial, Lannate showed good results but is not specifically labeled for this pest here and has a 7-day re-entry interval. If applied for control of potato leafhopper, Lannate may provide incidental control of thrips as well. (Source: Long Island Fruit & Vegetable Update, June 29, 2001, No. 17)   Ribes   Broken Branches on ‘Titania’ Black Currant Q:  I'm finding some of the fruit-laden branches on my 2nd-year Titania bushes are cracking near the base and flopping to the ground. I'm a new black currant grower, but this surprises me. Has it happened to other growers? Any advice? New Haven (near Middlebury), Vermont A:  I have been growing Titania for a number of years and find this problem every couple years. It is a high yielding variety and this year I have a number of plants breaking down. I have braced some of the canes by putting metal push in posts and supporting the canes with baler twine - like a fence. I am having this problem with other cultivars also, in spite of heavy pruning. They are all very heavy with fruit. Northumberland, PA (Source: The International Ribes Association TIRA Listserve, ribes-tira-l@cornell.edu ) The International Ribes Association is also constructing a new website.  Check it out at http://www.msu.edu/user/sleightd/tira/. Massachusetts Berry Notes is a publication of the University of Massachusetts Extension Fruit Program which provides research based information on integrated management of soils, crops, pests and marketing on Massachusetts Farms.  No product endorsements over like products are intended or implied.

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