Berry Notes is edited and articles written by Sonia Schloemann except where other contributors are noted. Publication is MASSACHUSETTS funded in part by the UMass Extension Agroecology Program and grower subscriptions. A text version can be e-mailed to BERRY NOTES you if you contact Sonia Schloemann at 413-545-4347, [email protected]. Please cite this source if reprinting May 27, 2003, Vol. 15, No. 6 information. Volume 15-- 2003 Message from the Editor: Summer Schedule: Berry Notes will appear on a weekly basis for the next 10 weeks or so. I will try to post it each Tuesday by 5:00pm. Any variation on this schedule will be announced a week ahead of time. As always, please feel free to send comments or questions about Berry Notes to me at [email protected]. Twilight Meeting: A twilight meeting will be held on Tuesday June 24, 2003 at Nourse Farms (http://www.noursefarms.com/ ) in Whately, MA starting at 5:30 pm. This meeting will showcase varieties of strawberries, raspberries, gooseberries and currants. Please contact either Nourse Farms (413-665-2658) or me (413-545-4347) for more information and directions. Crop Conditions: Strawberries: Wet weather during bloom has set the stage for high pressure for fruit rot diseases in strawberries. Regular fungicide applications during the bloom period should reduce, but may not eliminate fruit rot from the fields this year. (See the article on Botrytis Fruit Rot in the previous issue of Berry Notes) On the bright side, we have had few frost events this year (especially when compared to last year) so fruit set is very high. Cool weather has also delayed the season by about a week. More in some locations. This late start to the season may result in a shortened season overall, if the weather heats up and pushes ripening. Be ready. Insect pest management is an important post bloom activity. Tarnished plant bug is the main concern at this time. Blueberries: Mummyberry pressure has been high this year, especially in locations that have a history of infection. Indar® 75WSP has a section 18 Emergency Exemption label for use in blueberries this year and can be used until June 30. It also cannot be used any closer than 30 days to harvest. Bloom applications can help with the secondary infections of this disease. Please remember to fill out the Application Reporting Forms if you use Indar for mummyberry this year. Without these forms to document use, we have difficulty making the case for emergency labels in future years. The first fertilizer applications should go on during bloom and the second a month later. Growers should place Cranberry Fruit Worm traps out now. Raspberries are in early pre -bloom. Growers should be prepared for Anthracnose, Spur blight, and Cane blight in summer bearers. Keep an eye out for strawberry clipper damage in expanding raspberry flower clusters and for leaf feeding by raspberry fruitworm. Grapes are growing very slowly. Disease management is still a high priority. Keep and eye out for flea beetle damage to new foliage. Also, check under the bark of trunks and canes for evidence of mealy bug. Spring Arthropod Pest Management for Berry Crops Greg English-Loeb, Cornell University [Note: go to original article at http://www.nysaes.cornell.edu/pp/extension/tfabp/newslett/nybn25.pdf for outstanding pictures of these pests] Management of arthropod pests begins in earnest as the Also during the prebloom period (and extending through temperatures increase and the growing season gets under harvest and sometimes after renovation) two-spotted spider way. Before reviewing the list of potential arthropod mite can be a problem in some plantings. Look for whitish pests for each of the major berry crops, I want to or yellowish stippling on leaves. Current threshold is 5 mites comment on a few changes in chemical control options per leaf or about 25% of leaflets have at least 1 mite. This is for berry growers. Actually, not much has changed since likely a conservative threshold for a healthy planting and last year. As a reminder, Confirm 2F (Dow), an insect research currently being conducted should provide a better growth regulator with specificity against many estimate. There are several compounds labeled for mites on lepidopteran pests, received NY DEC approval last year strawberries in New York: Kelthane [dicofol], Vendex for use on blueberries with the principal target pest being [hexakis], Agri-mek [abamectin], Savey [hexthiazox], the cranberry fruitworm. Another Dow product, Spintor Acramite, Danitol [fenpropathrin] and Brigade. Kelthane, 2SC, has also received DEC approval for use in Danitol and Brigade are hard on predatory mites. Agri-mek blueberries. I have not had much experience with either label calls for 2 applications, 2 weeks apart. For all these of these materials although based on information out of materials, coverage is very important. The mites mostly stay New Jersery (courtesy of Dr. Sridhar Polavarapu), on the underside of leaves. Confirm is probably the better choice for cranberry Tarnished plant bug (TPB) is the key insect pest of fruitworm because of its longer residual activity. In strawberries during bloom to near harvest. Both adult bugs other news, a new miticide from Uniroyal (Acramite) and the nymphs cause injury (deformed fruit) but nymphs are has received both federal EPA and state DEC probably of the greatest concern for June-bearing cultivars. registration for use in a number of fruit crops including The economic threshold is half a nymph per flower cluster strawberries. (you sample by tapping cluster over a white plate and The Food Quality Protection Act, passed in 1996, counting nymphs that fall off). It is worth sampling for this required the EPA to review the label status of a number pest on a regular basis since it varies in population size from of older generation pesticides. Organophosphate place to place and from one year to the next. Spraying a insecticides were one of the first groups reviewed pesticide when nymph counts are below threshold costs you followed by carbamate pesticides. This review is still in money and can kill beneficial arthropods unnecessarily. progress. Last year I reported that azinphosmethyl Good weed management can help reduce problems with [Guthion] was slated to be cancelled on certain crops TPB. such as strawberries and grapes. However, as of now, Cyclamen mite is a potentially serious pest that seemed to this has not occurred and Guthion is still available. Note show up in more fields than usual two years ago but was not that phosmet [Imidan] and carbaryl [Sevin] are currently very prevalent in 2002. The mites get active in the spring under review, with particular focus on extending the re- with populations peaking after bloom. The mites like to feed entry interval. We will keep you posted on the outcome on young leaf tissue (just as the leaves are unfolding). The of these various activities. mites themselves are difficult to see without a good hand Strawberries lens. Cyclamen-damaged leaves tend to be stunted and During the prebloom period the strawberry bud weevil crinkled. Prior to bloom or after renovation are good times to (clipper) is the main arthropod pest to watch out for. In treat for this pest. Kelthane and Thiodan [endosulfan] are recent years we have learned that many strawberry labeled for use against cyclamen mites. Use lots of water for cultivars, such as Jewel and Seneca, can tolerate a fair thorough coverage. amount of bud loss from this pest, although at sufficient Two more insect pests deserve mention at this time. The first densities, it can still be a problem. As a rough rule of is Strawberry sap beetle (SSB) (see previous issue for more thumb, treat for clipper when you observe more than one details on biology and management of SSB). This small, clipped primary or secondary flower bud or more than 2 brownish beetle seems to be increasing as a pest in New York tertiary buds per truss, on more than one truss per foot of strawberries. Both the adult beetles and the larvae feed on row. Note that once flowers are open they are no longer ripe and overripe fruit. We still are exploring the best ways at risk from clipper. Clipper often is a more severe to control SSB. Two pyrethroids are labeled in New York problem along borders of plantings, near woods. for its control: Dantitol and Brigade. Note that Brigade does Lorsban [chlorpyrifos] and Brigade [bifenthrin] are not have a preharvest interval while for Danitol it is 2 days. labeled for clipper in New York. However, Brigade is more expensive. For both materials, 2 good coverage is likely to be important for its control. Tarnished plant bug (TPB) is another potential problem for Spittlebug starts appearing on leaves, stems, and raspberry growers during the period from bloom to harvest. flowering racemes about this time (bloom) and Both the adults and their nymphs can cause deformed fruit, extending into harvest. They overwinter as eggs in the although the deformities are not as obvious in raspberries as soil and hatch out as temperatures rise in the spring. The in strawberries where TPB is also an important pest (see nymphs crawl up the plant and begin feeding on the below). We do not have a good estimate of the economic xylem tissue (the water conducting vessels of the plant). threshold for TPB in raspberries but a rough guide would be There are not a lot of nutrients in xylem and therefore 10 to 20% of canes infested with adults or nymphs. Carbaryl nymphs need to process a lot of sap, extracting the few is labeled for control of TPB on raspberry.