Strawberry and Raspberry Pest Management in Wisconsin

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20 white) and mature fruit can be off-color, small, and of poor quality. Start monitoring for FT when the first flowers open. Tap opened flowers into a white or dark-colored shallow bowl; the disturbed thrips will fall into the bowl and can be counted. Count the number of thrips from 10 flowers from each of five areas in each field (total of 50 flowers per field). Do this weekly until most flowers have set. Published action thresholds are not research based, but have been derived from careful observation. Most commonly, the recommended threshold is about an average of 10 thrips per flower, though conservative thresholds as low as two thrips have been published. FT is significantly controlled with prebloom applications of insecticides targeted for strawberry bud weevil (“clipper”) and tarnished plant bug. Spinosad, spinetoram, and acetamiprid are all registered for controlling FT and all have a 1-day preharvest interval, meaning that it would be necessary to suspend picking for only one day if treatment was needed during the harvest period. Control FT as early as possible, preferably before 10% of the plants are in flower, to avoid killing pollinators. We still don’t know whether or not FT will become a pervasive problem in Wisconsin strawberries. As this insect is an annual immigrant to the state, in most years, population levels will probably be below the economic injury level. However, annual scouting of strawberries for this pest will allow quick action those occasional times when populations are larger than normal. Tarnished plant bug Tarnished plant bug (TPB) continues to be the most important insect problem facing Wisconsin strawberry growers. TPB is a sucking insect that feeds on the flower and young developing fruit. The resulting berry is stunted and has a concentration of seeds at the tip. Damage is similar to frost injury. Tarnished plant bug occurs in the field before the start of the blossom period and can be found throughout the year. The most damaging period is from blossom through the early growth of the berry. TPB should be monitored prior to the start of bloom, and again after the initial fruit have started to develop. Action thresholds (economic injury levels) for control of TPB have been developed; these are based on weekly pest monitoring. TPB monitoring is done in two ways. Starting with first flower bud formation, use an insect sweep net to sample for adults. Make five sets of 20 sweeps each per field. Treatment is advised if samples average more than four TPB per 20 sweeps (a total of at least 20 per 100 sweeps). The second method of sampling is used once the flower bud stems have elongated, but before flowers start to open. Tap flower bud clusters over a white pan or tray. Sample 100 clusters per field (such as 10 clusters in 10 locations, or 20 clusters in 5 locations randomly chosen throughout the field). This method samples both adults and nymphs (the latter can be as small as 1/16-inch). Published thresholds vary somewhat, but they range from an average of one TPB per cluster to one per four clusters. Use the more conservative threshold if you have experienced significant TPB damage in past years. Should tarnished plant bug occur at damaging levels, most insecticides will provide at least some control. However, bifenthrin, endosulfan, and fenpropathrin are the materials of choice when TPB numbers are very high.
Table 6. Spray schedule for strawberries—BEARING BEDS When to spray Problem Treatment Formulation Rate/acre Remarks EARLY SPRING Diseases (after uncovering plants; diseases should be treated as leaves are expanding) leaf diseases: angular leaf spot (see remarks) leaf blight leaf scorch leaf spot captan 50WP 3.0–6.0 lb copper various see label dodine 65WP 1.5–2.0 lb myclobutanil 40W 2.5–5.0 oz propiconazole EC 4.0 fl oz To control leaf diseases, start spraying before symptoms appear on foliage. If angular leaf spot has been a problem in previous years, include a copper fungicide (see “Disease Notes”). Copper may cause a slight chlorosis or yellowing of the foliage of some varieties; discontinue use if phytotoxicity occurs. red stele mefenoxam Gold EC 1.0 pt Apply in sufficient water to move the fungicide to the root zone. Insects PREBLOOM Insects (separation of blossom buds) aphids cyclamen mite aphids plant bugs spittlebug fosetyl aluminum 80WDG 2.5–5.0 lb Apply in sufficient water to thoroughly wet foliage. phosphorous acid rates vary Formulations and rates vary. See product labels. endosulfan 50WP 2.0 lb 3EC 1.3 qt malathion 25WP 6.0–8.0 lb 8EC, 8F 1.5–2.0 pt acetamiprid 30 SG 1.9-6.9 oz 70 WP 0.8-3.0 oz *bifenthrin WSB 6.4–32.0 oz carbaryl 80S 1.5–2.5 lb 50WP 2.0–4.0 lb 4F, XLR 1.0–2.0 qt endosulfan 50WP 2.0 lb 3EC 1.3 qt malathion 25WP 6.0 lb cyclamen mite endosulfan 50WP 4.0 lb 3EC 2.66 qt strawberry leafroller thrips *bifenthrin WSB 6.4–32.0 oz carbaryl 80S 1.5–2.5 lb 50WP 2.0–4.0 lb 4F, XLR 1.0–2.0 qt endosulfan 50WP 2.0 lb 3EC 1.3 qt malathion 25WP 6.0 lb spinetoram SC 6.0-10.0 fl oz spinosad Entrust 1.25–1.5 oz SpinTor 4.0–6.0 fl oz 2SC spider mite *abamectin 0.15EC 16.0 fl oz *bifenthrin WSB 16.0–32.0 oz fenbutatin oxide 50WP 1.5–2.0 lb *fenpropathrin 2.4EC 16.0–21.3 fl oz strawberry bud weevil (clipper) *bifenthrin WSB 6.4–32.0 oz chlorpyrifos 4E 1.0 qt If cyclamen mites are a problem, make a separate application of endosulfan 3EC at 2.66 qt (or 50WP at 4 lb) in 400 gal spray per acre (also controls aphids, spittlebugs, and plant bugs). Two aphicide treatments in spring before bloom and two in fall before mulching help control spread of strawberry viruses in new and bearing fields. Carbaryl may aggravate aphid and spider mite problems. *Fenpropathrin can be used for control of tarnished plant bug and spittlebug at the rate of 10.67 fl oz/a. Acetamiprid may also be used for thrips control at the rate of 4.0-6.9 oz/acre (30 SG formulation) or 1.7-3.0 oz/acre (70 WP formulation). If strawberry bud weevil has been a problem, two applications are suggested 10 days apart. Chlorpyrifos may be phytotoxic when applied in hot weather. * Restricted-use pesticide—can only be applied by a certified applicator. (continued) 21
Page 1 and 2: A1934 Strawberry & Raspberry Pest M
Page 3 and 4: INTEGRATED PEST MANAGEMENT FEDERAL
Page 5 and 6: PESTICIDES AND COMMUNITY RIGHT-TO-K
Page 7 and 8: Table 2. Examples of pesticides wit
Page 9 and 10: Table 3. Toxicity categories of pes
Page 11 and 12: Reportable spills involving SARA su
Page 13 and 14: Planter granular applicators can be
Page 15 and 16: Please note that this recycling pro
Page 17 and 18: Strawberry Disease Management Read
Page 19 and 20: Table 5. Disease resistance ratings
Page 21: Strawberry Insect Management INSECT
Page 25 and 26: Table 6. Spray schedule for strawbe
Page 27 and 28: Strawberry Weed Management A succes
Page 29 and 30: label for specific instructions on
Page 31 and 32: Table 8. Weed management for strawb
Page 33 and 34: Table 8. Weed management for strawb
Page 35 and 36: products are taken up through leave
Page 37 and 38: Raspberry Insect Management Several
Page 39 and 40: Table 9. Spray schedule for raspber
Page 41 and 42: Raspberry Weed Management Effective
Page 43 and 44: Table 10. Weed management for raspb
Page 45: SPRAY RECORD SHEET Date applied Mat

Strawberry and Raspberry Pest Management in Wisconsin

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