phone: (603) 862-1520  Hours: M-F, 8 a.m.- 5 p.m. Taylor Hall, 59 College Road, Durham, NH Directions. Brussels sprout plant leaves can be green to purple in color, and they’re arranged alternately on the stem. They prefer to feed on the youngest leaves and flowering parts and are often found deep within the heads of cabbages or Brussels sprouts. The second treatment was a rotation of two organic insecticides, insecticidal soap M-pede (Gowan Company, Yuma AZ) and Azera (Valent, Walnut Creek CA). Though not specifically tested, we were also able to document the effectiveness of scouting with economic thresholds to determine when to apply pesticides. Adult aphids may or may not be winged. Sow seed directly into the garden in mid-summer and provide plenty of water for best growth. Flowers did not reduce the amount of infestation of Brussels sprouts, and did not seem to be a good method of aphid control. Would different combinations or larger numbers of flowers provide better control? This condition produces loose sprouts. We also hypothesized that scouting and spraying the sprouts would provide some control. This resulted in 6 applications of Bt during the season at a rate of 0.5 lbs/acre. Also, ants tend to be attracted to the honeydew left by aphids, so an ant infestation may be symptomatic of an aphid problem. In 2013, a battery made of 1000 sprouts generated 63 volts, which were used to light up an eight-foot Christmas tree in Southbank, London. Would different arrangements of the flowers in relation to the Brussels sprouts (within, or even outside the plots) provide higher rates of parasitism of aphids? Observe and compare insect visitation of both control methods, focusing on insects that are predators or parasites of cabbage aphids. From conversations with growers in the region, we came to realize that many growers, especially organic growers, were struggling with cabbage aphid management We decided to conduct a study to compare two different methods of managing cabbage aphids: intercropping with beneficial flowers and using a rotation between two organic insecticides. The crops attacked include cabbage, brussels sprouts, kale, cauliflower, as well as wild mustard and shepherd's purse. However, the difference was not statistically significant. The Brussels sprouts (cv. Think of it as a zen exercise; makes it very contemplative, calming. Unfortunately, the plots with flowers actually attracted slightly more very infested sprouts than plots without the flowers. Late-maturing Brussels sprout plant leaves are at a high risk of damage by these pesky insects. Brussels sprouts are not difficult to grow but they are heavy feeders and need supplemental fertilization or heavily amended soil. Although growth rates slowed in mid-October, aphid numbers continued to rise into November. Although our research did not focus on the aphids, they were quite a nuisance and rendered most sprouts unmarketable. Most mature aphids are … The above photo shows extremely infested sprouts. Brussels sprouts (‘Brassica oleracea’) are healthy, delicious, long-season vegetables that belong to the cabbage family. These flowers were planted in random formation in the middle row of each of the four flower treatments. Cabbage aphids are green gray with a white, waxy coating. Beds were laid with 6 feet between bed centers. Some of the more common species are listed below. Aphids are small, gray-green, soft-bodied insects that are typically found in clusters on new-growth cabbage plants, like Brussels sprouts. The Brussels sprouts were planted 18 in apart in single rows into 1 mm embossed black plastic mulch. Which insecticides are most effective at controlling cabbage aphid. Rather than using a harmful insecticide to kill off aphids, there are several natural ways you can both manage an aphid infestation and prevent it from happening in the first place. However, cabbage aphid management in certified organic systems is very … https://homeguides.sfgate.com/brussels-sprouts-pests-diseases-40830.html We scouted for caterpillars and controlled them with Bt (Dipel DF, Valent USA) when necessary. However, the flowers did attract more insect enemies of aphids, notably parasitic wasps and syrphid flies. HORT COCO-UC MASTER GARDENER PROGRAM OF CONTRA COSTA Official Blog of the UC Master Gardener Program of Contra Costa County: Bugs on the Brussel Sprouts, University of Illinois Extension: Brussels Sprouts, University of California Statewide Integrated Pest Management Program: Brussels Sprouts, How to Care for a Curry Plant With Brown Tips on the Leaves, Black Caterpillars With Yellow Stripes That Eat Broccoli Leaves. Brussels sprouts are a cultivar of the cabbage family, which are grown for their small, edible leafy green buds (which resemble tiny cabbages). cabbage aphids. The control plot yielded 58% of the sprouts marketable with light cleaning, and the flower plot yielded about 43% of the sprouts marketable with light cleaning. Preventing Problems: Pull up and compost old plants, because cabbage aphids can overwinter in dead plant tissue. In 2016, we evaluated three different strategies to manage cabbage aphid in Brussels sprouts: 1) nothing, 2) organic insecticides, and 3) interplanting with a mix of flowers. They may be winged or wingless, and they have two antennae at the tip of the head and a pair of tube-like structures that jut out of their rear end. Generally speaking (and especially if aphids are not evident), you don’t have to wash Brussels sprouts because you are already “cleaning” them by trimming off the bottom and then peeling away a few outer leaves. Extended production is pos-sible as plants will tolerate temperatures down to 20 ... Brussels sprouts can be sold in pint or quart baskets or bags. These insecticides were applied when thresholds were met through the scouting protocol put forth by the University of California's Statewide Integrated Pest Management Program, found at http://ipm.ucanr.edu/PMG/r108300811.html. Diablo) slightly greater than ¼ acre. Scouting only took us about 30 minutes every week. This graph shows that the plots controlled by organic insecticide had greater than 80% clean sprouts at harvest time. Avoid broad-spectrum, persistent pesticides on or around Brussels sprouts to conserve the populations of beneficial insects. Photo credit: Alan Eaton, IPM Extension Specialist and professor at UNH. However, if a large aphid population has been feeding on your Brussels sprouts, it can cause the wilting and yellowing of leaves, and possibly even other damage (although it rarely kills the plant). Aphids, in particular, reproduce quickly, so you should learn how to keep your plants safe from these bothersome bugs. The aphids multiplied very quickly from early September until mid-October. All aphids are soft-bodied and pear-shaped with a pair of cornicles, or little horns, projecting from the rear end of their abdomens. Organic Spray Treatment: We scouted for aphids weekly and sprayed when the aphid levels met the economic thresholds described by University of California’s IPM resources. Sprouts are hardy, and they typically grow best during cool or even frosty weather. Scouting once a week and spraying when threshold levels were reached based on University of California’s chart (http://ipm.ucanr.edu/PMG/r108300811.html) appears to be key to controlling aphids. Excessive or fast-release nitrogen fertilizer applications encourage a flush of tender new growth that is especially attractive to aphids. Rotating organic insecticides Azera and M-pede controlled cabbage aphids on Brussels sprouts very well. You’ll still probably have to peel and discard the outer leaves. The field was fertilized prior to planting based on soil test recommendations, with 120 lbs/acre of N and 150 lbs/acre of K2O using a combination of 27-0- 0 and 0-0-22. We irrigated via drip irrigation for approximately two hours based on feel of the soil, which typically resulted in irrigation 2X per week. The treatments were laid out as follows: The first treatment was the control, where no form of aphid control was applied. First, check the undersides of the leaves; you may see the bugs themselves, or you may notice the sticky residue they leave behind after feeding. A single harvest of the entire plant means that Cabbage aphids on Brussels sprouts Symptoms Large populations can cause stunted growth or even plant death; insects visible on the plant leaves or sprouts and are small, grey-green in color and soft bodied and are covered with a white waxy coating; leaves … Aphids are small, soft bodied insects that feed by stabbing their hollow, sharply pointed mouthparts through the epidermis of the plant and then sucking the juices out of the cells. OF CABBAGE APHID ON BRUSSELS SPROUTS BY ALINA SOPHIA HARRIS Sustainable Agriculture and Food Production Systems, University of New Hampshire, 2012 THESIS Submitted to the University of New Hampshire in Partial Fulfillment of the Requirements for the Degree of These plants are easy to care for, although pest control and prevention are crucial if you want your Brussels sprouts to remain healthy. Clip off and compost stems holding aphid clusters. Their edible heads—like the sprouts on a brussels sprout plant—may appear damaged, stunted, or sickly. Aphids are small, gray-green, soft-bodied insects that are typically found in clusters on new-growth cabbage plants, like Brussels sprouts. We also hypothesized that scouting and spraying the sprouts would provide some control. Out of the five species of flowers that were planted to attract insect enemies of the cabbage aphid, three were much more effective than the other two. Always follow manufacturer instructions when working with an oil or soap and apply the material on a mild, cloudy day to plants that are not under water stress, if possible. However, soils that have been worked prior to planting are too loose to support good growth. The above graph shows that the alyssum flowers attracted the most syrphid flies, a predator of cabbage aphids. From 2013 to 2015, we performed experiments comparing different varieties of Brussels sprouts as well as different topping practices. We also rated the health of the Brussels sprout plants and the flowers during this data collection. Layout of the Brussels field on August 5th, showing the 12 total rows. The third treatment was polycropping the Brussels sprouts with a variety of flowers: alyssum, borage, marigold, phacelia, and cilantro. How to cure a cabbage aphid infestation. We hypothesized that mixing flowers in with the Brussels sprouts would provide some control of cabbage aphid levels on the sprouts by attracting insect enemies of the aphid. If you’re worried that a Brussels sprouts bug is eating leaves, there are a few key signs to look for. For scouting protocol, see https://nevegetable.org/crops/insectcontrol- 3. On Nov 11th we sampled 6 plants per plot and, for each plant, recorded the percentage of sprouts that were infested by aphids, had a few aphids that could be wiped off, or were free of aphids. Populations can fluctuate year to year—infestation rates can be damagingly high one year and almost zero in the subsequent year—possibly due to environmental factors, including rain, which can wash off the loosely attached aphids, and entomopathogenic fungi that attack the aphids and are more prevalent in wet conditions. Brussels sprouts grown in the UK are threatened by 46 different pests, including caterpillars, aphids, and various diseases. Feeding injury from cabbage aphid includes wrinkled, downw… There is a range of chemistries available among insecticides labeled for this pest: including pyrethroids and organophosphates, neonicotinoids, pymetorzine, and insecticidal soap. Brussel sprouts can power batteries. We sampled 6 leaves (2 lower, 2 middle, 2 upper) on 6 plants per plot. Her work has been published in Forbes, USA Today, Fodor's, Marriott Traveler, SAS Airlines, the Austin American-Statesman, Austin Monthly, and dozens of other print and online publications. The phacelia and cilantro were seeded on 6/2/2016, and all flowers were transplanted on 6/27/2016. The above graph shows that the flower plots consistently had more parasitized aphids, or “mummies”, which are caused by the parasitic wasp Diaratiella rapae. Flowers on August 5th, showing the marigold, alyssum, phacelia, and borage. Many varieties can t… If the cilantro and phacelia had been planted multiple times in sequence plantings, they may have kept flowering and attracted more insect enemies. Each plot was 13 plants long and 3 rows wide. We hypothesized that mixing flowers in with the Brussels sprouts would provide some control of cabbage aphid levels on the sprouts by attracting insect enemies of the aphid. The alyssum attracted the most syrphid flies. They got a good foothold, before I decided to do something. Aphid-infested brassicas will typically grow slowly or incompletely. Sprouts are harvested in fall when cool weather produces best flavor. Fall harvest in Kentucky is the most practical and rewarding. Most mature aphids are roughly 1/8-inch long. www.gardenanswers.com/plant-pests/aphids-on-brussels-sprouts Applying insecticidal soap to Brussels sprouts on a hot, sunny day can potentially injure the plants. Sustainable Horticulture State Specialist, Copyright © 2021 University of New Hampshire, TTY Users: 7-1-1 or 800-735-2964 (Relay NH), experiments comparing different varieties of Brussels sprouts as well as different topping practices, https://nevegetable.org/crops/insectcontrol-, Applied Vegetable & Fruit Research in New Hampshire, 2019-20 New England Small Fruit Management Guide, 2018-19 New England Vegetable Management Guide, Compare the percent marketable sprouts using these two control methods. https://www.growveg.com/guides/cabbage-aphid-controls-for-organic-gardeners Would different planting times for the flowers provide better control? Diablo), were seeded on 5/20/2016 and kept in the UNH MacFarlane greenhouses until transplanted into the field on 6/21/2016. Use a slow-release fertilizer, if possible. They commonly occur in dense colonies , often covered with waxy droplets. I have some cabbage worms that are tearing my Brussel Sprouts up. Brussels sprouts always get aphids worst, but I think that if you continue to keep them in check by consistently blasting them with water then you will get a harvest. Called honeydew, this sap dries into clear, shiny spots; the spots often turn black due to the fungus (called sooty mold) that grows on them. Is a rotation of insecticides necessary for control? We collected data every other week beginning on Aug 3rd, until Nov 4th on the number of aphids and all other insects observed on the Brussels sprouts as well as on the flowers. Our research raises several questions for future research: Many of our brussels sprouts were donated to the Cornucopia Food Pantry in Durham, NH. The cilantro and phacelia also attracted a decent number, but stopped flowering then died early in the season. https://www.kellogggarden.com/blog/gardening/growing-brussel-sprouts Below is a table of our history of pesticide applications to control cabbage aphid: Amount Sprayed (Dilution): 2.5 oz (2 oz/gal), Amount Sprayed (Dilution): 7.5 oz (2.5 oz/gal), Amount Sprayed (Dilution): 8 oz (2 oz/gal), Amount Sprayed (Dilution): 10 oz (2.5 oz/gal), Amount Sprayed (Dilution): 10 oz (2 oz/gal). Cabbage aphids are pests only of brassicas, with cabbage, cauliflower, broccoli, and Brussels sprouts being most severely affected. Aphids are usually present in spring and summer, although populations can increase by late summer and last well into fall. University, University of New Hampshire Cooperative Extension Hence, organic sprouts are hard to find. It also shows that with light cleaning, about 90% of the sprouts in the organic insecticide plots were marketable. The most effective flowers were the alyssum, cilantro, and phacelia. If you’re already dealing with aphids and you want to control them naturally, try: Finally, if you want to prevent aphids from occurring, be sure to take the following steps: Justine Harrington is based in Austin, where she writes about current trends in health, wellness, community, gardening and sustainability. Cabbage aphid numbers increased quickly starting around the beginning of September, and were just beginning to slow down by November. The sprouts form at the base of each leaf in a long stem. Growers across the globe and in Northeastern United States have reported economically damaging populations of cabbage aphid (Brevicoryne brassicae) in Brussels sprouts (Brassicacea). Luckily, low aphid populations do not typically result in plant damage. Both the flower plots and the control plots had fewer than 10% clean sprouts. The alyssum, borage, and dill were also seeded on 5/20/2016. University of Connecticut recommends a threshold of 10% infested plants in cabbage, broccoli, cauliflower and Brussels sprouts after heads or sprouts begin to form. During these trials, we experienced severe infestations of cabbage aphids. Cabbage aphids seemed to really start multiplying at the beginning of September. Late-maturing Brussels sprouts and cabbage are at high risk for damage by cabbage aphids. … https://greensideup.ie/mealy-cabbage-aphids-on-my-brussels-sprouts © Copyright 2020 Hearst Communications, Inc. Create a timeline of cabbage aphid levels throughout the growing season. The pest affects the Brassicacea family, which includes economically important agronomic, forage, horticultural, and forage crops. Each treatment was repeated four times throughout the field, which was a field of solid Brussels sprouts (cv. Monitoring and Treatment Decisions No special monitoring is needed for green peach or turnip aphids in cole crops; keep notes on them as you monitor the cabbage aphid. Insecticidal soap sprays, however, may be phytotoxic under some conditions and rates, especially in Brussels sprouts and cabbage. Each treatment was repeated four times throughout the field, which was a … The plots controlled by a rotation of organic insecticides showed very good control of aphids, while the plots with beneficial flowers or no pest control were very infested by aphids by harvest time in November. In 2016, we evaluated three different strategies to manage cabbage aphid in Brussels sprouts: 1) nothing, 2) organic insecticides, and 3) interplanting with a mix of flowers. Cauliflower, as well as different topping practices until transplanted into the garden mid-summer. Without the flowers marigold, phacelia, and they typically grow best during cool or even frosty weather bug... 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