Blueberries: Organic Production


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Blueberries: Organic Production

  1. 1. BLUEBERRIES: ORGANIC PRODUCTION HORTICULTURE PRODUCTION GUIDENational Sustainable Agriculture Information Service Abstract: Blueberries are the most widely grown fruit crop in the U.S. Blueberries are well-suited to organic culture, and good markets exist for organically grown blueberries. This production guide addresses key aspects of organic blueberry production, including soils and fertility, cultural considerations, pests, and diseases, as well as marketing. Additional resources are provided for further investigation.By George L. Kuepper and Steve DiverRevised 2001 by Katherine AdamRevised 2004 by Martin Guerena andPreston SullivanNCAT Agriculture Specialists©2004 NCATJune 2004 TABLE OF CONTENTS Introduction .................... 2 Choosing a Variety .............. 2 Soils and Fertility ............. 2 Cultural Considerations ......... 6 Insect Pests .................... 8 Diseases ....................... 11 Bird and Rodent Control ........ 16 Marketing ..................... 17 Economics ...................... 17 Photo Credits .................. 21 References ..................... 21 Photo by Scott Bauer Additional Resources ........... 23 2004 USDA Image Gallery Blueberry Electronic Resources on the World-Wide Web.............. 24ATTRA is the national sustainable agriculture information service operated by the NationalCenter for Appropriate Technology, through a grant from the Rural Business-Cooperative Service,U.S. Department of Agriculture. These organizations do not recommend or endorse products,companies, or individuals. NCAT has offices in Fayetteville, Arkansas (P.O. Box 3657, Fayetteville,AR 72702), Butte, Montana, and Davis, California.
  2. 2. blueberry (Vaccinium corymbosum) is the most Introduction widely cultivated, grown from the Mid-Atlantic to California, Oregon, and Washington, andThis publication focuses on organic blueberry from the Upper Midwest to the Mid-South. Theproduction, specifically the highbush and rab- lowbush (wild) blueberry (V. angustifolium) isbiteye species, and is most relevant to production adapted to the far North and is commerciallyconditions east of the Rocky Mountains. It does important in Maine, Eastern Canada, and parts ofnot go deeply into many of the basics of blueberry New Hampshire, Massachusetts, Michigan, andculture—variety choice, planting, pruning and Wisconsin. Rabbiteye (V. ashei) is a large bushtraining—which are largely the same under both well-adapted to the South, in the region roughlyorganic and conventional management. Such south of Interstate 40. Southern highbush (V. cor-general information is available from the Coop- ymbosum x V. darrowi), a new hybrid, is adapted toerative Extension Service and many horticulture the southern rabbiteye zone as well as the coastalbooks, periodicals, and bulletins. Nor does South. It has a lower chilling-hours requirement,this publication address organic production of and it flowers and fruits earlier than highbush orlowbush blueberries. The Maine Organic Farm- rabbiteye varieties.ers and Gardeners Association (MOFGA) andK-Ag Laboratories International in Wisconsin Blueberries have fewer pest problems than mostboth have information on organic culture of na- other fruits, offering an advantage for organictive, unimproved lowbush blueberries. (See the production. In some areas, most insect and dis-Electronic Resources section of this publication ease problems can be controlled through cul-for contact information.) tural manipulation and proper cultivar selection. Weather fluctuations and geographic seasonalWhile anyone may choose to grow organically, advantage are the major economic considerationsthe USDA National Organic Program (NOP) now for variety selection.regulates the labeling, marketing, and record-keeping procedures of all products labeled as The National Organic Standard is unclear on theorganic. If you have a commercial farm and plan precise requirements for planting stock whento market your produce as organic, you will need establishing a perennial crop like be certified, unless your gross farm income is Historically, non-organic transplants could beless than $5000. To learn about organic certifica- used to establish perennial crops. However, iftion and the steps involved in it, read ATTRA’s conventional planting stock were used, mostOrganic Farm Certification & the National Organic certifiers required that the plants be grown atProgram. least 12 months under organic conditions after transplanting before any harvested productBlueberries adapt well to organic culture. Pro- could be marketed as organic. It is likely, butduction costs may be somewhat higher using not certain, that most certifiers are continuingorganic methods, but this can be effectively coun- that policy. Therefore, it is important that youterbalanced by premium prices. Many cultural discuss your plans with your certifier prior topractices, such as the use of deep mulching and making a purchase.sodded row-middles, work for both conventionaland organic blueberry production systems, offer-ing a more sustainable approach to commercial Soils and Fertilityhorticulture. The Importance of Soil pH Choosing a Variety Blueberries are distinct among fruit crops in their soil and fertility requirements. As members ofBlueberries are members of the genus Vaccinium the Rhododendron family, blueberries require anand belong to the Rhododendron family (Eri- acidic (low pH) soil, preferably in the 4.8 to 5.5caceae). The Vaccinium genus contains several pH range. When soil pH is appreciably higherspecies of economic importance. The highbush than 5.5, iron chlorosis often results; when soilPAGE 2 //BLUEBERRIES: ORGANIC PRODUCTION
  3. 3. pH drops below 4.8, the possibility of manga- Powdered sulfur takes about one year to oxidizenese toxicity arises. In either case, plants do not and reduce soil pH. Prilled sulfur takes some-perform well. what longer. Limestone, used to increase pH, requires several months to a year to effect changesBlueberries have a relatively low nitrogen re- in pH, and reactive time is highly dependent onquirement and thrive on organic fertilizers. the fineness of the grind.Soil pH also plays a significant role in nitrogenmanagement for blueberries. Research shows Single applications of sulfur should not exceedthat blueberries prefer soil and fertilizer nitrogen 400 pounds per acre. Best results are obtained byin the ammonium form, absorbing and using it applying up to 200 pounds in spring, followedmuch more efficiently than nitrate nitrogen—the by up to 200 in the fall, for as many applicationsform preferred by most other commercial crop as are required to deliver the total amount. It isplants. Neutral and high-pH soils favor nitrifica- advisable to re-test the soil one year after eachtion—the rapid conversion of ammonium nitro- application to determine whether additionalgen to nitrate through the activity of nitrifying acidification is necessary.(Pritts and Hancock,microorganisms. In an acidic soil, however, the 1992)ammonium form of nitrogen predominates andis readily available to blueberries. For instance, Organic growers should be conservative inwhen a slow-release organic fertilizer like fish- the application of soil sulfur. Sulfur has bothmeal is applied, the nitrogen in the proteins is fungicidal and insecticidal action and can detri-converted first into ammonium. This ammo- mentally affect soil biology if overused. Organicnium—which would rapidly convert to nitrate growers sometimes increase their applications ofunder neutral soil conditions and be leached out peat moss at planting time, since it too is a soilof the root zone—tends to remain in the desired, acidifier (pH 4.8), reducing the need for sulfur.ammoniated form and thus be held in the soil The Ozark Organic Growers Association sug-for uptake. gests as much as 5 to 10 gallons of peat moss per blueberry plant. While costly, peat is resistant toPerhaps the most common method of lowering decomposition and provides the benefit of soilsoil pH in organic culture is by applying sulfur. humus. Those seeking alternatives to sphagnumPre-plant incorporation of sulfur to lower the pH peat moss might consider pine bark or similarto an optimal blueberry range of 4.8 to 5.5 should amendments incorporated in the planting rows orbe based on a soil pH test. Because soil pH is holes. While less desirable than sphagnum peatsubject to considerable seasonal fluctuation—es- moss, pine bark often can be obtained locally atpecially on cropped soils—it is advisable to do a much lower cost.soil sampling and testing in winter or very earlyspring, when biological activity is low. Table 1 It is advisable to monitor soil pH over time be-provides guidelines for sulfur or lime to raise or cause production practices can cause graduallower pH on different types of soil. changes to occur. Irrigation water often con- Table 1. Approximate pounds per acre of sulfur or ground limestone to change soil pH one unit.(Whitworth, 1995) Soil Texture Pounds per acre of sulfur Pounds per acre of lime to to lower raise Sand (CEC=5) 435 to 650 1000 Loam 870 to 1300 2800 Clay (CEC=25) 1300 to 1750 4400 //BLUEBERRIES: ORGANIC PRODUCTION PAGE 3
  4. 4. tains calcium and magnesium, which may cause can be useful in these areas, including Overviewsoil pH to creep upwards, while repeated use of of Cover Crops and Green Manures, Manures for Or-acidifying fertilizers, such as cottonseed meal, ganic Crop Production, and Farm-Scale Compostingmay lower pH.(Spiers and Braswell, 1992) Fortu- Resource List.nately, the presence of abundant organic materi-als such as peat and the breakdown products of Once a blueberry planting is established, supple-sawdust and woodchip mulches tend to buffer mental fertilization can be applied in a number ofsoil pH. Several organic growers have even ob- forms and by several means. Generally, supple-served that blueberries grown in high organic mental nitrogen is the greatest concern, followedmatter soils will perform well at a pH as high as by potassium. Blueberries have a low phospho-6.0 with few apparent problems. As a result, ad- rus requirement and typically require little, ifditional sulfur (or lime, for that matter) seldom is any, phosphorus fertilization. In fact, excessiveneeded. When needed, sulfur is usually applied phosphorus has been one of the factors linked toas a top dressing, but delivery of soluble sulfur iron chlorosis in blueberries. High calcium levelsthrough drip irrigation lines also is an option. are also undesirable.Vinegar or citric acid solutions may also be ap-plied through drip lines to provide acidity. Nitrogen fertilizer recommendations vary some- what from region to region. As a general guide-Blueberry Fertilization Practices line, 100 to 120 pounds of nitrogen per acre are commonly recommended on mulched berries;Soil-building practices prior to establishment a reduced rate of 50 to 60 pounds per acre iscan go a long way toward providing the fertil- advised where little or no mulch is used.(Clark,ity necessary for a healthy blueberry planting. 1987) In conventional production, nitrogen isHigh levels of soil organic matter are especially often applied in three split applications—one atimportant in blueberry culture, contributing to bud break, followed by two more at six-weekthe soil’s ability to retain and supply moisture intervals. Adjustments may be necessary forto the crop, buffering pH, and releasing nutri- less-soluble organic fertilizers. One rule of thumbents through decay. Soils rich in organic matter suggests that these fertilizers be applied from oneare also a desirable environment for symbiotic to four weeks ahead of the recommended sched-mycorrhizal fungi that assist blueberry roots in ule for soluble fertilizers. This allows additionalabsorbing water, nitrogen, phosphorus, and other time for the decomposition processes to make nu-minerals.(Yang et al., 2002) Green manures in trients available. Applications after mid-July areadvance of planting can play an important part discouraged, as they tend to promote late growthin cycling organic matter into the soil system, that is particularly sensitive to freeze can applications of composts and livestock Table 2 shows natural materials used by organicmanures. ATTRA has several publications that growers for supplementary fertilization. Table 2. Natural materials for supplementary fertilization.(Penhallegon, 1992, and Nitron, no date) Material Estimated N-P-K Characteristics Alfalfa meal 3-1-2 Slow to medium N release Good micronutrient source Blood meal 12-1.5-0.6 Medium N release, 6-8 weeks Cottonseed meal 6-2.5-1.7 Slow N release, 4-6 months Feather meal 13-0-0 Slow N release, 4-6 months Fish meal 10-4-0 Slow N release, 4-6 months Soybean meal 7-1.6-2.3 Slow N release, 4-6 months Compost Variable Analysis depends on feed stock Fortified compost Variable Analysis depends on materials addedPAGE 4 //BLUEBERRIES: ORGANIC PRODUCTION
  5. 5. Current fertilization practices among organic Potassium for blueberries is often adequately pro-growers vary considerably. In one example vided through decaying mulches. The need for(Moore et al., 1994), an organic blueberry grower further supplementation should be determinedin the Missouri Ozarks applied ½ pound of by soil and/or tissue testing. Where additionalfeather meal per mulched plant in late May of the potassium is needed, it can be applied in a num-establishment year, followed by a similar applica- ber of mineral forms—including sulfate-of-pot-tion four to six weeks later. In subsequent years, ash-magnesia or K-Mag,™ granite meal, andan additional (third) application of ½ pound of greensand. Some forms of potassium sulfatefeather meal was made earlier, in mid- to late- are also allowed in organic production. See yourMarch. As the feather meal products available certifier before buying this region contain roughly 13% nitrogen,this grower was applying approximately 141 High-quality compost is an all-around good blue-pounds of actual N per acre in the establishment berry fertilizer. Depending on the humus condi-year, and an annual total of 212 pounds per acre tion and biological activity in the soil, compostthereafter. may provide all the fertility needs of the crop. Where compost is of average quality, it may stillUsing the same schedule of split applications, function as a good soil conditioner. Using agedanother organic grower in the Arkansas Ozarks, animal manures in blueberry production also isalso growing mulched berries, applies cottonseed possible, but less common.meal (estimated at 7% N) at 1 pound per planteach time—that’s two times in the establish- Fertigation—the practice of injecting solublement year and three times in subsequent years. fertilizers through drip irrigation lines—is aAt these rates, this grower is applying roughly common practice in conventional blueberry152 pounds per acre in the establishment year production. Since fertigation is based on theand about 229 pounds per acre in subsequent complete solubility of fertilizers in water, thereyears.(Watkins, 1988) However, it should be are limited options among organic fertilizers.noted that many sources of cottonseed meal are Early attempts at fertigation with blood meal bycontaminated and will not be allowed in organic Arkansas blueberry growers resulted in cloggedproduction. Contact your certifier first. emitters and algae growth. In the 1990s, however, researchers in California successfully demon-Associate professor John Clark (1987) at the strated the use of spray-dried fish protein andUniversity of Arkansas believes the fertilization poultry protein in drip systems.(Schwankl andrates used by many organic growers are probably McGourty, 1992) In addition, several organicexcessive. Despite the slower release of organic- liquid fertilizers—derived from fish emulsion,based nitrogen, the carry-over from previous seeds, kelp, or seaweed—are available.seasons probably results in roughly the sameamount of nitrogen released each season as is Unlike the roots of grapes and bramble fruits,being applied. which grow well into the inter-row area, blue- berry roots are not very extensive. As a result,Clark suggests that the best way to determine all fertilizers and acid-forming amendments mustwhether fertilization rates are “on target” is to be applied under the plant canopy to assure thattest foliar nitrogen levels annually. This testing they reach the done in late July or early August (in Arkansas)by sampling leaves from the mid-shoot area on Foliar feeding of blueberries is practiced by somefruiting canes and sending them to an analytical organic growers and is especially helpful whenlaboratory. Lab results showing nitrogen levels plants are stressed. Foliar fertilization programsbelow 1.6% indicate a nitrogen deficiency; a level usually employ seaweed and fish emulsion. Theabove of 2.2% indicates excess nitrogen. This ser- Ozark Organic Growers Association has recom-vice is available through Cooperative Extension mended a seaweed-fish mix applied three timesin Arkansas and other states. Several commercial per growing season—at bud break, just prior tolaboratories also provide foliar analysis. ATTRA harvest, and just after harvest. More detailedidentifies laboratories that offer various soil and information is available in ATTRA’s Foliar Fer-plant tissue-testing services in its publication tilization publication.Alternative Soil Testing Laboratories. //BLUEBERRIES: ORGANIC PRODUCTION PAGE 5
  6. 6. produce seed that may be scattered into the rows Cultural Considerations and germinate later. In a Texas study, researchers demonstrated thatPlant Spacing the inter-row area could be used to produce significant quantities of mulch for rabbiteyeHighbush blueberries are typically spaced 4 to blueberries. Successful winter crops of rye, rye-4½ feet in the row, with 8 to 12 feet between grass, and crimson clover, and a summer crop ofrows. As bushes can get quite large at matu- pearl millet, were grown, cut, and windrowedrity, many growers find that 10– to 12–foot row onto the blueberry rows. Nitrogen proved thespacings—approximately 900 to 1090 plants major limiting factor for non-leguminous coverper acre—are preferable for tractor operations crops; low soil pH and browsing deer limited(mowing, harvesting, and spraying). Rabbiteyes the biomass production of legumes. Pearl milletare typically spaced at 5 to 8 feet within a row, demonstrated the greatest level of allelopathicwith 12 to 14 feet between the rows, or 388 to 726 (natural production of plant chemicals by oneplants per acre. plant that inhibit other plants growing nearby) weed suppression.(Patten et al., 1990)Dr. J.N. Moore and others at the University ofArkansas have experimented with denser within- In some systems that employ sodded middles,row plant spacings for highbush blueberries, ef- a weed-free strip 6 to 12 inches wide often isfectively doubling the number of plants per acre. maintained between the edge of the mulch andYields during the first five years after planting the cover crop. The strip reduces competitionwere found to be substantially higher (a boon between the cover crop and berry bushes, andto the overall economics of blueberry produc- lessens the chance that weeds or the cover croption—especially where growers have made high itself will advance into the mulch. It has theinvestments in drip irrigation and bird netting). added advantage of discouraging cutworms, an occasional pest in blueberries. In organicThese researchers have been careful to point out, systems, this strip is maintained without the usehowever, that beyond the fifth year, inter-plant of herbicides.competition may create problems, requiring re-moval of every other plant in the row.(Pritts and Organic growers typically employ mechanicalHancock, 1992) Fortunately, highbush blueber- cultivators of various types to maintain the weed-ries transplant easily, and removed bushes can free strip. Gordon Watkins (1989) describedbe used to establish a new field. two modified “off-the-shelf” cultivators used by growers in the Ozark region. One, referred to as the Vasluski Edger, uses a single disc from a riceInter-row Management levee plow in conjunction with two shanks from a spring-tooth chisel. These are mounted on aBlueberries do not have extensive root systems. tool-bar that extends past the rear tractor tire. TheAs a result, clean cultivation of row middles to disc cuts a strip along the row edge and throwscontrol weeds and to incorporate cover crops is soil towards the plants, while the shanks stir soilless damaging to blueberries than it is to bramble closer to the bed. The result is a weed-free stripfruits. Still, it is wise to till no deeper than 3 about 6 to 8 inches wide. The drawback of thisinches. Similarly, inter-row living mulches—also implement is the amount of dirt shifted by thecalled sodded middles—generally are not competi- disc and the resulting “ditch.”tive with the crop unless the inter-row speciesare aggressive and invade the rows. Fescue is The second implement Watkins describes is thecommonly used in the Mid-South for sodded Lilliston Rolling Cultivator,™ with all the headsmiddles, as are several other grass species. removed except the two extending beyond one rear tire. One head rolls in the ditch area thatTimely mowing—usually three to five times is (or would be) created by the Vasluski Edger.per year—is the common means of controlling The second extends approximately 12 inches ontoweeds and other vegetation in sodded middles. the side of the bed. Depth of penetration is setIt is most important that weeds not be allowed to at 1 inch, and the implement is best operated atPAGE 6 //BLUEBERRIES: ORGANIC PRODUCTION
  7. 7. relatively high speeds. Since it cultivates about that an optimum vegetation-free zone during theone-half of the bed surfaces, only about a 2-foot first two to three years of growth extends roughlystrip remains for hand pulling and hoeing. The 1.5 to 2.5 feet from the plant. This translates to atool works well on small weeds but does not 3- to 5-foot-wide, weed-free row bed.control larger, well-established weeds. Current recommendations suggest mulching aFlame, steam, and infrared thermal weed-con- 3- to 4-foot-wide strip under the plants with 3 totrol systems are other options. In the 1980s and 5 inches of sawdust, bark, wood chips, or wood’90s, flame weeding made a rapid comeback as a shavings. Organic growers often prefer a deepernon-chemical weed control technique, especially mulch of up to 6 inches over a strip at least 4 feetamong organic farmers. However, this technique wide. Ideally, the mulch should be sufficientlyis not always practical or safe around flammable coarse to minimize crusting, and the surfacemulch materials. ATTRA can provide additional relatively flat to encourage water penetrationinformation on flame weeding. and gas exchange.In-row Weed Management and While the mulch suppresses many weeds, the moist organic medium can also become a havenMulching for annual weeds (annual ryegrass, stinging nettle, crabgrass) as well as perennial weeds (dan-Weeds are considered by many growers to be delion, horsetail, sheep sorrel) that find a niche inthe number one problem in organic blueberry perennial plantings. Strategic attention to weedculture. It is especially important to control ag- control, even in mulched fields, is a major culturalgressive perennial weeds such as johnsongrass, consideration. Tractor-drawn cultivation imple-bermudagrass, and quackgrass prior to crop ments are impractical for in-row weed controlestablishment. Sites with these grasses should on deep-mulched blueberries because blueberrygenerally be avoided for blueberry establish- roots often grow into the mulch, and significantment. Details of pre-plant and post-plant weed plant damage can result from tillage. Shallowmanagement for all fruit plants are provided in hoeing or hand-pulling weeds are two traditionalATTRA’s Overview of Organic Fruit Production. options practiced by many organic growers.Some techniques, however, deserve additionalelaboration. Weeder geese can also eliminate most of the grass and many of the tender broadleaf weedsIn much of the country, blueberries are grown from a planting. They are prone to eating ripeon mulched, raised beds. Rabbiteyes and old fruit, however, and may damage some of thehighbush plantings are commonly grown with- newly emerging canes, so their use should beout mulch. Raised beds reduce the incidence of timed accordingly. Obviously, goose stockingsoil- and water-borne diseases. Thick organic rates are much lower, and management easier,mulches provide weed and disease suppres- on clean cultivated plantings. Investigators atsion, soil temperature regulation, slow-release the Kerr Center for Sustainable Agriculture havenutrients, organic matter, and moisture conserva- used weeder geese for effective weed control intion. The latter is especially important because blueberries with sodded middles. The Center’sblueberry roots lack root hairs—the primary sites strategy involves using movable electric fencingfor water and mineral absorption on most plants. and intensive grazing. One possible drawbackThis characteristic makes water management of cited by Kerr Center researchers is the tendencyparamount concern and goes a long way toward of geese to compact the soil and mulch. ATTRAexplaining why irrigation and mulching are rec- can supply further information on weeding withommended practices. geese.The importance of maintaining a weed-free zone A promising alternative to organic mulchingaround blueberries was demonstrated in a Geor- is the use of fabric weed barriers. While fabricgia study(NeSmith et al., 1995) using rabbiteye mulches may not provide all the benefits ofblueberries—which have a more vigorous root deep organic mulch, they are highly effective forsystem than highbush. Researchers determined weed control and allow water to pass through. //BLUEBERRIES: ORGANIC PRODUCTION PAGE 7
  8. 8. And, though the initial cost is high, it may provereasonable when amortized over the fabric’s Insect Pestsexpected lifetime of 10 to 12 years. All fabricmulches must be removed, however, before theydeteriorate and decompose into the soil. Have a Rabbiteye blueberries seem more tolerant of in-plan in place to deal with this eventuality. Avail- sect damage than highbush varieties. Althoughable fabric mulches include Sunbelt by DeWitt insect damage in blueberry plantings rarelyCompany (see References). reaches economic thresholds, regular monitoring by scouting and use of insect traps is advised.Non-porous black plastic mulches—commonly As discussed in the previous section, the use ofused in vegetable production—are not recom- beneficial insect habitats along crop field bordersmended for blueberries. Polyethylene plastic increases the presence of beneficial insects. If youmulch encourages surface rooting—making the are releasing purchased beneficial insects, theseplants more susceptible to drought stress and field-edge habitats will encourage them to remainwinter injury—and the plastic does not allow and continue their life cycle in that location,water to pass through. helping reduce the pest populations. However, pests may also inhabit the field-edge habitats; therefore, these habitats should be monitoredPollination along with the crop field. For additional informa- tion, request ATTRA’s publications BiointensiveBlueberries are insect-pollinated; thus, increasing Integrated Pest Management and Farmscaping tothe number of pollinators can be quite beneficial. Enhance Biological Control.Blueberry flowers vary greatly in size and shape,depending on species.(Lyrene, 1994) Therefore, Depending on the locations of blueberry plant-having a variety of pollinators like horn-faced ings and the insect pressure on them, sanitation,bees, mason bees, carpenter bees, bumblebees, good cultural practices, vigorous plant growth,orchard bees, and others is important for good and natural biological control will handle mostfruit set. pests. However, when specific pests reach eco- nomically damaging levels, additional action isSeveral varieties of blueberry require cross-pol- necessary. The following discussion identifieslination, and almost all varieties yield better as some common blueberry pests and alloweda result of it. In a pollination study, the variety organic controls. This information was takenPatriot, and possibly Northland, benefited from largely from Cornell University’s Crop Profiles:cross pollination, while the variety Bluecrop Blueberries in New York (Harrington and Good,did not; therefore, highbush blueberry planting 2000), where more detailed information can bedesign must be based on the pollination require- found.ments of the particular variety.(MacKenzie, 1997)Identify the pollinators that are most efficientfor the variety and encourage them to remain inthe area by creating insect habitats. Cover cropsand adjacent vegetation may act as habitats forbeneficial insects that provide pollination andhelp suppress pest insects and mites. When cropsand field borders are managed with beneficialsin mind, they often are referred to as refugia,and represent a new approach to attractingpollinators and natural enemies of pests, basedon planned biodiversity. To learn more aboutrefugia, request the ATTRA publication Farms-caping to Enhance Biological Control. Additional Figure 1. Blueberry maggot adult fly.information on using various bees as pollinators Used with permission. By G.J. Steck and J.A. Paynecan be found in ATTRA’s Alternative Pollinators:Native Bees.PAGE 8 //BLUEBERRIES: ORGANIC PRODUCTION
  9. 9. Blueberry stem borer This beetle, Oberea myops, causes damage in two ways. First, egg deposits can cause the first 3 to 4 inches of the current season’s growth to wilt or die. This is evidenced by girdling in two places, approximately ½ inch apart, on the injured twig. Secondly, grubs can cause canes to die. Leaves will turn from green to yellow and drop off, and the cane will die. Pinholes along the shoot with yellowish strings hanging from them are indica- By Jerry A. Payne, USDA ARS, tive of this problem.The most common insect pest is the blueberry This pest can be controlled by removing wiltedmaggot, Rhagoletis mendax. It attacks the fruit in tips below the insect damage and burningmidsummer before harvest and feeds on all va- them.rieties of blueberries. It is found throughout theeastern U.S. and Canada. This pest overwinters Cranberry fruitwormin the pupae stage, buried 1 to 2 inches in the soil.The adult flies emerge over a period of a month Particularly troublesome inor two during summer. They lay eggs in ripe the eastern U.S., the cranberryberries, and the maggots eat the pulp of the fruits, fruitworm, Acrobasis vaccinii,causing many to drop, spoiling the sale of oth- affects both cranberries anders, and creating difficulties in post-harvest care. blueberries. It overwinters inThrough degree-day calculations based on soil the soil as a fully grown larvatemperatures, one can predict the emergence of and completes developmentthe flies—934.3 degree days at the low tempera- in the spring. Adult mothsture threshold of 41°F (Teixeira and Polavarapu, mate and lay eggs from bloom2001)—and implement appropriate measures to until late green fruit, usuallyprevent or control maggot damage. Figure 3. Photo used with permission By on unripe fruit. The eggs are C.D. Armstrong. very small and difficult to see.The choice of blueberry varieties can influence Cranberry fruitworm Young larvae enter the stemthe severity of blueberry maggot damage. In a adult moth. end of the fruit and feed on theRhode Island study, the early ripening varieties flesh. They often web berriesEarliblue and Bluetta were found to have fewer together with silk. A Michigan study reports thatmaggots than late maturing varieties whose rip- many parasites attack the cranberry fruitworm.ening periods were synchronized with the fly’s The most common larval parasitoid is Campoletisegg-laying period. Of the mid- to late-seasonvarieties, Northland and Herbert stood out withless damage.(Liburd et al., 1998)The botanical insecticides rotenone and pyre-thrum can be effective in controlling blueberrymaggots, but they can also be toxic to beneficialinsects, fish, and swine. The spinosad-type insec-ticide Entrust™ (Dow AgroScience) is approvedfor use on organic crops including blueberriesand has been reported effective against the blue- Figure 4. Cranberry fruitworm larva.berry maggot. Additionally, disking, cultivating, By C.D. Armstrong. Photo used with permission.and off-season grazing by fowl can reduce pupapopulations. patsuiketorum (Hymenoptera: Ichneumonidae); the most common parasitoid recovered from the fruitworm’s hibernating structure was Villa //BLUEBERRIES: ORGANIC PRODUCTION PAGE 9
  10. 10. lateralis (Diptera: Bombyliidae).(Murray et al.,1996) Therefore, maintaining refugia, by en-hancing field borders for beneficial insects, andproper sanitation are especially important incontrolling this pest. Additionally, eliminatingweeds and vegetative litter around plants helpscut down on overwintering protection for fruit-worm cocoons.The biocontrol Bacillus thuringiensis (Bt) can ef-fectively control cranberry fruitworm. Makesure to use a Bt product approved for organicproduction. The spinosad insecticide Entrust Figure 5. Japanese beetle skeletonizing a leaf. Photo used(Dow AgroScience) is registered for use against with permission. University of Maryland Cooperative Extension Home and Garden Information Center.the cranberry fruitworm and cherry fruitwormon blueberries. spore (which provides a long term approach to larvae reduction), trapping away from the crop,Cherry fruitworm and regular emptying of the traps.The cherry fruitworm, Grapholitha packardi, which Clean harvesting prevents the accumulationbores into the fruit and feeds extensively below of overripe fruit, reducing the attraction forthe surface, can be very damaging to blueber- beetles. In a Michigan study, fields with tilledries. It causes injury within a few days of hatch- row-middles had significantly fewer larvae thaning. This pest overwinters as mature larvae in those with permanent sod, and larval abundancehibernating structures on the blueberry bushes, was significantly lower on the interiors of thewith larvae pupating in the spring. The adults fields compared to the perimeters.(Szendrei etappear in about a month (this varies by seasonal al., 2001) Clean row middles may have fewerconditions). Adult moths mate and lay eggs on Japanese beetle larvae, but they also leave the soilunripe fruit. open to erosion, so this option should be used only on level fields.Pruning and burning the cut limbs helps controlthe cherry fruitworm, because the hibernating Some botanical insecticides—such as rotenone—larvae are contained in these limbs. The cherry can legally be used even on the day of harvestfruitworm is a lepidopteran pest, and organically according to current label restrictions; however,approved control products include B.t. or the none have proven adequate for Japanese beetlespinosad product Entrust. control. Kaolin clay, available in the product Surround, can be used for suppression of theJapanese beetle Japanese beetle only on blueberries that will be processed.The Japanese beetle larvae develop in pastures,lawns, and other types of turf, where they live in Leafrollerthe soil. Adults emerge in early summer and feedon blueberry foliage and berries, causing injury Leafrollers are the caterpillars of a few species ofto the berries, as well as decay from fruit-rotting small moths. These pests roll leaves (hence theirpathogens. name) to use as shelter during their metamor- phosis. Adults emerge, mate, lay eggs, and thenOrganic growers use a number of methods to con- repeat the cycle at least twice each year. Larvaetrol these pests. Hand picking, trapping, milky feed on green berries, ripe berries, and leaves.spore disease, and/or beneficial nematodes have Small numbers of leafrollers (fewer than 15 perall been used by growers with varying degrees of plant) usually will not cause significant losses,success. The key practices are the use of milky unless they are feeding on blossoms.(Elsner and Whalon, 1998)PAGE 10 //BLUEBERRIES: ORGANIC PRODUCTION
  11. 11. The pesticide Bt var kurstaki can be applied when is favorable for the disease to develop. Chang-insects are feeding. Additional organically ac- ing one of these three factors may prevent thecepted strains of Bt can be effective at egg hatch, disease from occurring. Pathogens responsiblebecoming less effective as larval size increases. for blueberry diseases include fungi, bacteria,Neemix, a product containing azadirachtin, acts nematodes, and viruses. If these pathogens areas an insecticide and insect growth regulator af- present, manipulation of the environment and thefecting young (1st and 2nd instar) caterpillar pests. host, to make it less susceptible, help to manageIt is registered for leafrollers on organic blueber- diseases on blueberries in a more sustainableries with an “R” (regulated) status. manner. Check with your nursery and local Extension office to see whether known diseasesLeafhopper are prevalent in your area. Then, plant tolerant or resistant blueberry varieties.Leafhoppers are small, mobile insects that are Managing soil health is key for successful controloften found on stems or the undersides of leaves. of soil-borne diseases. A soil with adequate or-They feed by piercing the plant surface to suck ganic matter can house large numbers of organ-plant juices.(Elsner and Whalon, 1998) Leafhop- isms (e.g., beneficial bacteria, fungi, amoebas,pers transmit a microorganism that causes stunt nematodes, protozoa, arthropods, and earth-disease. In areas where stunt disease is a known worms) that in conjunction deter pathogenicproblem, leafhopper control is suggested. The bo- fungi, bacteria, nematodes, and arthropods fromtanical pesticide sabadilla, as well as insecticidal attacking plants. These beneficial organisms alsosoap and diatomaceous earth, are reported to be help foster a healthy plant that is able to resist pesteffective against these pests. Surround (for pro- attack. For more information, see the ATTRAcessing blueberries) and Neemix are registered publication Sustainable Management of Soil-bornefor leafhopper control on blueberries. Kaolin Plant Diseases.clay in Surround can be used for suppression ofleafhoppers on processing blueberries only. The plant’s leaf surface can also host beneficial organisms that compete with pathogens forAphids space. A disease spore landing on a leaf surface, for example, has to find a suitable niche for it toAphids, or plant lice, are related to the leafhop- germinate, penetrate, and infect. The more ben-per. They feed on the undersides of the youngest eficial organisms there are on the leaf, the greaterleaves and on tender shoots, and reproduce very the competition for the disease-causing spore try-rapidly. Aphids transmit blueberry shoestring ing to find a niche. Applying compost teas addsvirus, which can be very damaging to commercial microorganisms to the plant’s surface, making itblueberry producers.(Elsner and Whalon, 1998) more difficult for diseases to become established. Note, however, that there are restrictions on theAphids have many natural enemies like lady- use of compost tea prior to harvest. Be sure tobugs, lacewings, and parasitic wasps. Encourag- consult your certifier. For more information oning these natural enemies with habitat plantings disease controls, see the ATTRA publicationscan keep aphids and other pests on blueberries Notes on Compost Teas and Use of Baking Soda asbelow economic thresholds. Remove the virus- a Fungicide.infected plants, which will have bright red streaksor straplike leaves. Avoid overfertilization of the A blueberry diagnostic tool from Cornell Uni-crop. Organic growers can also use insecticidal versity has a step-by-step exercise that can aid asoap to control aphids. blueberry grower in determining what diseases may be affecting the crop. The diagnostic tool can be found at the following Web site: Diseases pritts/BerryDoc/blueberry/BBparts.htmDiseases in plants occur when a pathogen is pres- Diseases common to blueberries include mummyent, the host is susceptible, and the environment berry, Botrytis blight (gray mold), stem blight, stem canker, phytophthora root rot, blueberry //BLUEBERRIES: ORGANIC PRODUCTION PAGE 11
  12. 12. Figure 6. Mummy berry Figure 7. Mummy berry with apothecia Figure 8. Infected leaves and flower budFigures 6,7,8Credits: Photos used with permission. Nova ScotiaAgriculture and Fisheries Agriculture Center.stunt, and several viral diseases. For proper The fungus survives the winter on dead twigsdisease identification, consult Cooperative Exten- and in organic matter in the soil. The disease ission Service publications and related literature. more severe when excessive nitrogen has beenMany states also have plant pathology laborato- used, where air circulation is poor, or when frostries associated with their land-grant university has injured blossoms. Varieties possessing tightthat can provide diagnosis. fruit clusters are particularly susceptible to this disease. Remove dead berries, debris, and mulchFoliar diseases from infected plants during the winter and compost or destroy it. Replace with new mulch,Mummy Berry (Monilinia vacinii-corymbosi) and do not place mulch against the trunk of the plant.This fungus overwinters in mummified berriesthat have fallen to the ground. Sod or moss Highbush blueberry varieties are more resistantdirectly under the plant will contribute to spore to mummy berry than are rabbiteye. Rabbiteyeproduction. To control this fungus, remove varieties that showed lower levels of infectioninfested fruit (“mummies”) from the plant, rake were Coastal, Delite, Centurion, Walker, Cal-and burn mummified berries, or cover the fallen laway, and Garden Blue.(Ehlenfeldt et al., 2000)berries with at least two inches of mulch. Culti- Highbush varieties that exhibited constant re-vation during moist spring weather will destroy sistance to mummy berry were Northsky, Reka,the spore-forming bodies. Strategies that lead to Northblue, Cape Fear, Bluegold, Puru, andearly pollination of newly open flowers may be Bluejay.(Stretch and Ehlenfeldt, 2000)useful in managing mummy berry disease in thefield, since studies show that newly opened flow- This fungus overwinters in dead or diseaseders are the most susceptible to infection and that twigs, fruit spurs, and cankers. Spores are re-fruit disease incidence is reduced if pollination leased in the spring and are spread by rain andoccurs at least one day before infection.(Ngugi wind. Varieties in which the ripe fruit hangset al., 2002) for a long time on the bush prior to picking are especially susceptible. Removal of infectedPAGE 12 //BLUEBERRIES: ORGANIC PRODUCTION
  13. 13. Botrytis Blight (Botrytis cineria)Figure 9. Botrytis Blight Figure 10. Infected flower clustersPhotos used with permission. Nova Scotia Agriculture and Fisheries, Agriculture (Collectotrichum acutatum and C. gloeosporioides) Figure 12. Orange SporesFigure 11. Anthracnoseinfected fruit oozing out of berry.Photos courtesy of Dr. P. Bristow, Washington State University, Puyallup, //BLUEBERRIES: ORGANIC PRODUCTION PAGE 13
  14. 14. twigs by pruning and frequent harvesting arebeneficial to control. Old canes and small twiggywood should be removed in order to increase aircirculation around the fruit clusters. Immediatepostharvest cooling will significantly reduce theincidence of this disease.Stem Blight (Botryosphaeria dothidea)Stem blight shows up as a wilting, browning,or reddening of the infected leaves, which fre- Figure 14quently precedes the death of the plant. This is Figures 13 and 14. Symptoms of Botryosphaeria Stem Blighta vascular disease that most often starts from a Rust (Pucciniastrum vaccinii)wound infection site. The most typical symptom Photos used with permission. Bill Cline, Plant Pathology Extension, North Carolina State University.would be a flag (limbs killed by the disease thatdo not drop their leaves). The stems can be cutopen to reveal a light-brown discoloration. Rust is a serious leaf-defoliating problem for southern highbush varieties. The first yellowRemoval of infected wood, pruning about 12 leaf-spot symptoms appear in late spring to earlyinches below the discolored part of the limb, is summer. The yellow spots turn reddish-brownthe only practical control for Botryosphaeria stem as yellow-to-orange pustules show up on the bot-blight. Since infection can spread throughout the tom sides of leaves. Finally the infected leavesgrowing season, growers should prune during turn brown and drop off prematurely. Remedialdormancy. Fertilizer management is necessary action includes removing and burning infectedto prevent the formation of succulent shoots late vegetation. Multiple reinfestations are possiblein the season. Infection of cold-injured shoots during one growing season. Native evergreenaround the base of the bush is a primary way for berries (but not hemlock) are suspected as thethis fungus to enter the plant. The worst cases overwintering source and a necessary alternativeof stem blight occur on soils that are extremely host for completion of the fungus life cycle. Itsandy or on heavy peat soils that promote exces- may be beneficial to remove native species in thesive growth. Clove oil inhibits fungal growth and Vaccinium genus—which include sparkleberry,spore germination of Botryosphaeria dothidea and huckleberry, gooseberry, and bearberry—fromcould be effective in controlling this disease on areas adjacent to cultivated bushes.several woody plant species such as blueberry.(Jacobs et al., 1995) Be certain any clove oil prod- Phytophthora Root Rot (Phytophthora cinnamomi)uct you use is properly formulated and allowedin organic production. Root rot occurs more often on southern highbush plants than on rabbiteyes. The first symptoms are general unthriftiness leading to yellowing and reddening of leaves. Necrosis will appear on small rootlets and progress to a discoloration on the main roots and crowns. Eventually the plants will drop their leaves and die. Controls include use of clean nursery stock and good field drainage. Heavy soils that become waterlogged or have a high water table should be avoided. Plants can be grown on raised beds to reduce risks. Varieties resistant to Phytophthora include the rabbiteye varieties Premier and Tifblue and Figure 13 the highbush variety Gulf Coast.(Smith and Hepp, 2000)PAGE 14 //BLUEBERRIES: ORGANIC PRODUCTION
  15. 15. Blueberries’ shallow roots may benefit from thesoil-disease suppressive qualities of an organicmulch.Phomopsis Twig Blight (Phomopsis species)Tip browning and dieback are classic symptomsof this disease. Then elongated brownish cankersup to 4 inches long appear on stems. The fungusoverwinters in infected plant parts. Spores arereleased from old cankers in the spring; rain isnecessary for spore release. Temperatures rang-ing from 70 to 80°F encourage infections, andmoisture stress predisposes the plant to infection.The disease is most severe after winters in whichmild spells are interspersed with cold periods. Figure 16Growers should prune and destroy infectedplant parts. Avoid mechanical damage such as Figures 15 and 16. Phomopsis Twig Blightthat caused by careless pruning and cultivating. symptomsAvoid moisture stress by using irrigation duringdry periods. A fall application of lime sulfur after Photos used with permission. Highbush Blueberry Production Guide, NRAES, Cooperative Extension, Ithaca, New York.the leaves have dropped helps reduce diseasespores. Spring application of lime sulfur should Fusicoccum Cankerbe made early before warm weather occurs, toavoid injury to plants. Refer to your state’s spray Fusicoccum is a stem disease causing dieback andguide for recommended rates and timing. Careful general plant decline. This fungus overwintersvariety selection can greatly reduce the severity in cankers. Spores are largely disseminated byof twig blight. The varieties Elliott and Bluetta rainwater, and cold stress may play a part inhave proved resistant to Phomopsis twig blight. increasing disease damage. Removal of infected(Baker et al., 1995) plant parts is essential for control. Varieties differ in their resistance to this disease. Figure 15 Figure 17. Fusicoccum Canker (Fusicoccum species) Photo used with permission. Highbush Blueberry Production Guide, NRAES, Cooperative Extension, Ithaca, New York. //BLUEBERRIES: ORGANIC PRODUCTION PAGE 15
  16. 16. Viral diseases Bacterial diseaseControl of vectors, like aphids and leafhoppers, Bacterial Crown Gall (Agrobacterium tumefaciens)and sanitation of pruning and propagating ma-terials are important steps in controlling viral The crown gall bacterium does not grow well indiseases. Once a plant is infected, diagnosing it an acidic environment, so this disease is uncom-and culling it from the field is critical to prevent mon where soil pH is maintained in the optimumthe virus from spreading. range for blueberries.Shoestring disease Bird and Rodent ControlSymptoms appear as red discoloration in the mid-vein of a leaf, which then develops abnormallyinto wavy, distorted, or crescent shapes. Other Birds are a common pest of blueberries. Theirthan buying disease–free plants, destroying wild impact varies, depending on location and birdplants near the planting, and removing diseased density. Oregon reported up to 60% crop lossplants, control does not exist. Some cultivars from birds.(Main et al., circa 2000) In a Floridapossess genetic resistance or tolerance. study (Main et al., circa 2000), blueberries pro- tected with bird netting yielded the same asStunt those unprotected. Various methods of control have been tried—including “scare-eye” balloons,With this disease, plants lose vigor and become Mylar reflective tape, and sonic devices—withyellowish and dwarfed. The yellow-tipped varying levels of success. The problem withleaves remain small, rounded, and often puck- most repellents or scare tactics is that birdsered. The only known carrier is the sharp–nosed become habituated to the stimulus, renderingleafhopper, though other vectors probably exist. it ineffective after a short time. Sometimes,Diseased bushes cannot be cured. They must be growers overcome this problem by changingremoved from the field as soon as they are diag- the stimulus frequently—e.g., switching fromnosed. Agitation of the bush during removal will balloons to Mylar tape, or moving the balloonsdislodge the leafhoppers, causing them to move from one site to another. Properly applied birdto a neighboring healthy bush. netting has provided consistent and predictable control, but it is expensive to purchase and setScorch virus up. At the time of this writing (2004), the cost for ¾-inch bird netting 14 feet wide by 100 feet longThis virus causes severe dieback, blossom blight- is $85 plus shipping; 14 feet by 200 feet is $175,ing, and significant yield reduction on susceptible plus shipping; while a 5000 foot roll of 14-footvarieties, eventually killing its host. First, the wide netting runs $1800 plus shipping. For a Webflowers turn brown and fade to a greyish color site that sells bird netting, see <www.bird-away.before they fall off, though with the West Coast com/html/bird-netting.html>.strain of the virus, the dried flowers can be re-tained on the bush for more than a year. Produc- An Illinois study (Anon., 1991) found that thetion drops off and the plants do not recover. The yield increase on net-protected blueberries paidvirus is spread by aphids or by planting infected 80% of the costs of installation at a problem site.stock. The first line of defense is to plant virus- As growers report a 10-year life expectancy forfree stock obtained from a nursery that under- netting, the investment proved profitable by thegoes regular virus testing. Otherwise, remove second year.infected plants when symptoms appear and afterthe disease has been diagnosed by testing. Also, Rodents, primarily voles, can be a problem incontrol aphids in the blueberry field. Replant blueberries, because they inhabit mulches andwith virus-free stock. Most University Extension feed on roots and bark. Several other soil dwell-Service State offices have a disease diagnostic ers such as moles and shrews may also be present.service for plant samples. Shrews are carnivores that feed on grubs and worms; however, their tunneling can harm thePAGE 16 //BLUEBERRIES: ORGANIC PRODUCTION
  17. 17. plants. Rodent problems are largely confined flavonoids, vitamin C, anthocyanins, and phe-to plantings that are mulched and those with nolic acids.(Medders, 2001) Among the sellingpermanently sodded middles. Clean cultivation points are that blueberries are a good source ofprovides little shelter and disturbs burrows, but antioxidants and vitamin C, that the tannins init also creates an erosion hazard. Organic alter- blueberries can help prevent urinary tract infec-natives include trapping, encouraging predators tions, and that ½ cup of blueberries contains only(e.g., setting out perches to attract hawks, and owl 40 calories.(Anon., 2002)boxes for barn owls), frequent mowing of soddedmiddles, and managing fencerows and adjacent For more information about marketing options,areas to discourage migrants.(Hauschild, 1995) see the ATTRA publications Direct Marketing, Farmers’ Markets, and Adding Value to FarmFor details on options for rodent control, please Products: An Overview. On-farm, value-addedrefer to ATTRA’s Overview of Organic Fruit Pro- blueberry products usually require setting up aduction. This publication also discusses manage- rural enterprise besides farming, and may entailment of bird problems. Cooperative Extension considerable additional planning, management,and the U.S. Fish and Wildlife Service also have and start-up expense. Co-packers are an alterna-information on rodent and bird control. tive to doing your own processing. Blueberries are a popular “U-Pick” crop. When Marketing acreage exceeds the capacity of U-Pick custom- ers, whether 5 or 15 acres, hired labor becomes necessary. One rule of thumb suggests that 10 to 15 pickers per acre are required during the heightThere are a number of marketing options for or- of the harvest season.ganic blueberries. Fresh blueberries can be mar-keted directly through roadside stands, U-Pick For a good article on marketing blueberriesoperations, on-farm sales, and farmers’ markets. from a New Jersey blueberry farm, see <www.There are also well-established wholesale mar- for both fresh and frozen blueberries. shtml>.While highbush blueberries are grown for both For more information, see Blueberry Marketingfresh fruit and processing markets, “nearly half of Options, from the Northwest Berry & Grape In-the cultivated blueberries grown are sold as fresh formation Network, available on-line at <http://blueberries,” according to the North American Council.(Anon, no date) Since returns blueberry/mopt.htm>.to the grower usually are higher for fresh berries,most organic growers choose that option. Additionally, the Wild Blueberry Association of North America (WBANA) Web site, <www.As local retail markets become saturated, many>, promotes marketing andgrowers will also sell their berries wholesale is an excellent source of information on produc-through growers’ cooperatives. This is a common tion practices.option for organic growers, especially where or-ganic collectives have helped to identify premiummarkets. Some value-added processing optionsinclude frozen berries, jams, and juice. EconomicsA breakthrough in value-added marketing Organic blueberries typically sell for about 20%came in the late 1990s, when scientific research more than conventionally grown blueberries.indicated special health benefits associated Nationally, a survey conducted by the Organicwith blueberry consumption.(Staff, 2000; Anon, Farming Research Foundation showed that or-1999; Lazarus and Schmitz, 2000) More farm- ganic blueberry growers received between $1.00ers are now looking at marketing blueberries and $3.50 per pound for fresh berries in 1997 andas a healthy “functional” food that contains that wholesale prices for fresh organic blueberries //BLUEBERRIES: ORGANIC PRODUCTION PAGE 17
  18. 18. were 20% to 100% higher than for conventional Below are two of their budgets for conventionalblueberries, depending on supply and demand. highbush blueberries (Table 3 and 4).(Krewer, 2001)Highbush blueberries typically start producingin the third season, and yields increase annuallyfor the next four years. At full capacity, blueber-ries yield about 3 tons per acre. As blueberriesare expensive to establish and maintain, growersoften do not realize a return on their capital in-vestment until the seventh year. Well-maintainedblueberry bushes remain productive for at least15 to 20 years.Blueberries ripen fairly predictably, accordingto the region in which they are grown. In heavybearing years, market prices can drop dramati-cally, with early-bearing regions faring well andlate-bearing regions doing poorly. Harvest pat-terns follow a sequence beginning with rabbiteyesfrom Georgia and Texas, followed by highbushberries from North Carolina and the SouthernInterior Highlands (Arkansas, Tennessee, Ken-tucky, and Missouri). These are followed by theNorthern Interior Highlands, New Jersey, andso on. In years of overproduction, harvest pricesdo not even cover the cost of picking. Therefore,factors affecting local supply (such as late springfrost and the number of blueberry farms in yourarea) can play a major role in profitability.Blueberries are a highly perishable crop, and ef-ficient post-harvest handling is critical. Berry flatsshould be quickly refrigerated following harvest.For the commercial grower, a walk-in cooler isa must, as is a grading and packing shed. TheMississippi State University Extension Servicepublication Costs & Returns Associated with Pro-ducing Commercial Blueberries, available on-lineat <>, provides more detailed informationon the economics of blueberry production, in-cluding costs for irrigation, fertilizer, yields basedon plant age, labor requirements, field operationcosts for establishment, and more. While cost andreturn estimates will vary by state, the publica-tion can serve as a useful planning guide.For a budget showing establishment and main-tenance costs for blueberry production, see thishighbush blueberry budget from Penn State:<>.PAGE 18 //BLUEBERRIES: ORGANIC PRODUCTION
  19. 19. Table 3. Per-acre Cost Estimates for Fresh-market Highbush Blueberries* Costs Land Your Planting Your Mature Your Preparation Estimate year 0 Estimate year 4+ EstimateVariableCustomoperations 74.60 34.80 6.00Fertilizer 311.00 16.00 32.00Weedcontrol 0.00 129.64 212.10Insectcontrol 0.00 10.88 74.85Diseasecontrol 0.00 0.00 103.24Seed 48.00 60.00 0.00Plants 0.00 2,001.00 0.00Irrigation 0.00 620.00 120.00Mulch 0.00 250.00 0.00Beerental 0.00 0.00 25.00Labor 8.00 400.05 5,526.19Fuel 0.00 4.23 7.32Maintenance 0.00 3.12 8.07Interest 22.62 188.13 16.87TotalVariable 464.23 3,717.84 6,131.63FixedEquipment 0.00 6.22 14.71Land 100.00 100.00 100.00TotalFixed 100.00 106.22 114.71TotalCosts 564.23 3,824.06 6,246.35*Demchak, K., J.K. Harper, and G.L. Greaser. 2001. Highbush Blueberry Production.Agricultural Alternatives. Pennsylvania State University College of Agricultural Sciences. //BLUEBERRIES: ORGANIC PRODUCTION PAGE 19
  20. 20. Table 4. Returns above total costs for various prices and yields*Price Yield - pounds/acre 4000 6000 8000 10,000Dollars/pound $ $ $ $ 0.75 -646 -446 -246 -46 1.00 354 1054 1754 2454 1.25 1354 2554 3754 4954 1.50 2354 4054 5754 7454 1.75 3354 5554 7754 9954 2.00 4354 7054 9754 12,454 2.25 5354 8554 11,754 14,954*Demchak, K., J.K. Harper, and G.L. Greaser. 2001. Highbush Blueberry Production. Agricul-tural Alternatives. Pennsylvania State Univeristy College of Agricultural Sciences.PAGE 20 //BLUEBERRIES: ORGANIC PRODUCTION
  21. 21. Figure 17. Highbush Blueberry Production Photo Credits Guide, NRAES-55, published by NRAES, Co- operative Extension, P.O. Box 4557, Ithaca, New York. 14852-4557.Figures 1 and 2. Steck, G.J., and J.A. Payne, No Blueberry Maggot, University of FloridaInstitute of Food and Agricultural Science. ReferencesFigures 3 and 4. Armstrong, C.D. No date. Uni-versity of Maine, Cooperative Extension. Anon. 2002. Remind customers of blueberry’ benefits. The Seasonal Marketer. July. p. 8.worm.htm Anon. 2000. Blueberry elixir reverses age-re-Figure 5. University of Maryland Cooperative lated symptoms. Agriculture Research (USDA).Extension Home and Garden Information Cen- February. p. Anon. 1999. Blueberries may provide anti-ageinghtml boost. Earth Save. 6, 7, and 8. Nova Scotia Agriculture andFisheries Agriculture Center. Delbridge, Rick. Anon. 1991. Cost-effectiveness of anti-bird net-1995. Monilinia Blight of Lowbush Blueberry. ting for blueberries. HortIdeas. April. p. 42.8 Anon. No date. The cultivated blueberry market.wildblue/disease/monilini.htm North American Blueberry Council. 9 and 10. Delridge, Rick. 1995. BotrytisBlight of Lowbush Blueberry. Nova Scotia Ag- Baker, J.B., J.F. Hancock; and D.C. Ramsdell.riculture and Fisheries, Agriculture Center. 3 p. 1995. Screening highbush blueberry for resistance to Phomopsis canker. HortScience.wildblue/disease/botrybli.htm Vol. 30, No. 3. p. 586-588.Figures 11 and 12. Dr. P. Bristow, Washington Clark, John. 1987. Associate Professor of Hor-State University, Puyallup, WA. In: Bristo, P. ticulture, University of Arkansas at Fayetteville.2002. Blueberry Anthracnose. Crop Protection Personal communication. March 18, 1997.Factsheet, British Columbia, Ministry of Agricul-ture, Food and Fisheries. 5 p. Cox, K.D., and H. Scherm. 2001. Oversummer survival of Monilinia vaccinii-corymbosi in relationFigures 13 and 14. Cline, W.O. No date. Stem to pseudosclerotial maturity and soil surface en-Blight of Blueberry. Plant Pathology Extension, vironment. Plant-Disease. Vol. 85, No. 7.North Carolina State University, Fruit Disease p. 723-730.Information Note 9. Delbridge, Rick. 1995. Monilinia Blight of Low-fdin009/fdin009.htm bush Blueberry. 8 p. Nova Scotia Agriculture and Fisheries Agriculture Center.Figures 15 and 16. Highbush Blueberry Produc- Guide, NRAES-55, published by NRAES, wildblue/disease/monilini.htmCooperative Extension, P.O. Box 4557, Ithaca,New York 14852-4557. DeWitt Company. 8 DeWitt Drive, Sikeston, 63801. 573-472-008, 800-888-9669 //BLUEBERRIES: ORGANIC PRODUCTION PAGE 21
  22. 22. Ehlenfeldt, M.K., and A.W. Stretch. 2000. Main, Martin B., T.A. Obreza, and Ginger Allen.Mummy berry blight resistance in rabbiteye circa 2000. Comparison of ‘Gulf Coast’ blueberryblueberry cultivars. HortScience, Vol. 35, No. 7. yields in southwest Florida with and without birdp. 1326-1328. exclusion netting. University of Florida Exten- sion Service. EDIS. 6 p.Harrington, Eric, and George Good. 2000. CropProfile for Blueberries in New York. Cornell Medders, Howell. 2001. Let food be thy medicineUniversity. March 9. 18 p. Available from and medicine thy food. Arkansas Land and Life. Summer. p. 8-11.nyblueberries.html Menge, John. 2002. Biocontrol of PhytophthoraHauschild, Karen I. 1995. Vole management in cinnamomi. 3rd California Conference on Biologi-small fruit plantings. Northland Berry News. cal Control, Davis, CA.December. p. 22–24. Moore, J.N., M.V. Brown, and B.P. Bordelon.Jacobs, Karel A., J.C. Locke, and M. Carter. 1995. 1994. Plant spacing studies on highbush blue-Inhibition of Botryosphaeria dothidea mycelia berries. Arkansas Farm Research. July-August.growth and conidial germination by botanical 8-9.extracts, insecticidal soap and clove oil, 1994-5.Agricultural Research Service, USDA TEKTRAN. Murray, D.A., R.D Kriegel, J.W. Johnson, and A.J. Howitt. 1996. Natural enemies of cranberry fruit-000006/49/0000064970.html worm, Acrobasis vaccinii, (Lepidoptera: Pyralidae) in Michigan highbush blueberries. Great LakesKerr Center for Sustainable Agriculture P.O. Box Entomologist. Vol. 29, No. 2. p. 81-86.588 Poteau, OK 74953. 918-647-9123. NeSmith, D. Scott, and Gerard Krewer. 1995.Krewer, Gerald. 2001. Suggestions for Organic Vegetation-free area influences growth and es-Blueberry Production in Georgia. University of tablishment of rabbiteye blueberry. HortScience.Georgia. Fruit Publication 00-1. May. Vol. 30, No. 7. December. p. 1410– Ngugi, H.K, H. Scherm, and J.S. Lehman. 2002.Lazarus, Sheryl A., and Harold H. Schmitz. 2000. Relationships between blueberry flower age,Dietary flavonoids may promote health, prevent pollination, and conidial infection by Moniliniaheart disease. California Agriculture. Septem- vaccinii-corymbosi. Phytopathology. Vol. 92, No.ber/October. p. 33-39. 10. p. 1104-1109.Liburd, O.E., S.R. Alm, and R.A. Casagrande. Nitron. No date. Nitron’s Product Guide for1998. Susceptibility of highbush blueberry cul- Natural Fertilizers & Soil Conditioners, publishedtivars to larval infestation by Rhagoletis mendax by Nitron Industries, Fayetteville, AR.(Diptera: Tephritidae). Environmental Entomol-ogy. Vol. 27, No. 4. p. 817-821. Patten, Kim, Gary Nimr, and Elizabeth Neuen- dorff. 1990. Evaluation of living mulch systemsLyrene, P.M. 1994. Variation within and among for rabbiteye blueberry production. HortScience.blueberry taxa in flower size and shape. Journal Vol. 25, No. 8. August. p. 852.of the American Society of Horticulture Science.Vol. 119, No. 5. p. 1039-1042. Penhallegon, Ross. 1992. Organic Fertilizer NPK Values. January. In Good Tilth. p. 6.MacKenzie, K.E. 1997. Pollination requirementsof three highbush blueberry (Vaccinium corym- Pritts, Marvin, and James Hancock (ed.). 1992.bosum L.) cultivars. Journal of the American Highbush Blueberry Production Guide. North-Society of Horticulture Science. Vol. 122, No. 6. east Regional Agricultural Guide. Northeast Re-p. 891-896. gional Engineering Service, Ithaca, NY. 200 p.PAGE 22 //BLUEBERRIES: ORGANIC PRODUCTION
  23. 23. Sampson, B.J., and J.H. Cane. 2000. Pollina- Whitworth, Julia. 1995. Blueberry helps: fertil-tion efficiencies of three bee (Hymenoptera: izing blueberries. Issue 1. In: Horticulture Tips.Apoidaea) species visiting rabbiteye blueberry. Oklahoma State University Cooperative Exten-Journal of Economic Entomology. Vol. 93, No. sion. Stillwater, OK. March. 1 p.6. p. 1726-1731 Yang W.Q., B.L. Goulart, K. Demchak, and Y.D.Schwankl, Lawrence J., and Glenn McGourty. Li. 2002. Interactive effects of mycorrhizal inocu-1992. Organic fertilizers can be injected through lation and organic soil amendments on nitrogenlow volume irrigation systems. California Agri- acquisition and growth of highbush blueberry.culture. September–October. p. 21–23. Journal of the American Society for Horticultural Science. Vol. 127, No. 5. p. 742-748.Smith B.J., and R.F. Hepp. 2000. Susceptibilityof southern highbush blueberry cultivars to phy-tophthora root rot. Proceedings of the Seventh Additional ResourcesInternational Symposium on Vaccinium Culture,Chile. Acta-Horticulturae. No. 574. p. 75-79. Baker, M.L., and K. Patten (eds.). 1990. TexasSpiers, J.M., and J.H. Braswell. 1992. Soil-ap- Blueberry Handbook. Texas A&M, Overton,plied sulfur affects elemental leaf content and TX. 100 p.growth of ‘Tifblue’ rabbiteye blueberry. Journalof American Society of Horticulture Science. Vol. Caruso, Frank L., and Donald C. Ramsdell. 1995.117, No.2. p. 230-233. Compendium of Blueberry and Cranberry Dis- eases. APS Press, St. Paul, MN. 87 p.Staff. 2000. Blueberry elixir reverses age-relatedsymptoms. Agriculture Research (USDA). Feb- Doughty, C.C., E.B. Adams, and L.W. Martin.ruary. p. 23. 1981. Highbush Blueberry Production. Washing- ton-Oregon-Idaho Cooperative Extension ServiceStretch, A.W., and M.K. Ehlenfeldt. 2000. Re- Bulletin. PNW 215.sistance to the fruit infection phase of mummyberry disease in highbush blueberry cultivars. Eck, P., 1988. Blueberry Science. Rutgers Univer-HortScience. Vol. 35, No. 7. p. 1271-1273. sity Press, New Brunswick, NJ. 284 p.Szendrei, Zsofia, Nikhil Mallampalli, and Rufus Eck, P. and N.F. Childers (ed.). 1966. BlueberryIsaacs. 2001. Effect of cultural practices on Japa- Culture. Rutgers University Press, New Bruns-nese beetle in Michigan blueberries. Paper from wick, NJ. 378 p.the Entomological Society of America AnnualMeeting, San Diego. Elsner, Erwin A., and Mark E. Whalon. 1998. Common Blueberry Insect Pests and TheirTeixeira, L.A.F., and S. Polavarapu. 2001. Post- Control. Michigan State University Extension.diapause development and prediction of emer- September.gence of female blueberry maggot. (Diptera: Environmental Entomology. Vol.30, No. 5. p. 925-931. Galletta, Gene J., and David G. Himelrick (eds.). 1990. Small Fruit Crop Management. PrenticeWatkins, Gordon. 1989. Non-toxic weed control Hall, Englewood Cliffs, NJ. 602 blueberries. Ozark Organic Growers Associa-tion newsletter. May. p. 6–7. June–July. p. 6–7. Gough, R.E. 1995. The Highbush Blueberry and Its Management. Food Products Press, NY.Watkins, Gordon E. 1988. Organic Blueberry 272 p.Culture. Proceedings of the Seventh AnnualOklahoma Horticultural Industries Show. Janu- Johnston, S., J. Mouten, and J. Hull, Jr. 1969.ary 28–29. p. 45-51. Essentials of Blueberry Culture. Michigan State University Extension Bulletin. E-590. //BLUEBERRIES: ORGANIC PRODUCTION PAGE 23
  24. 24. Moore, J.N. 1976. Adaption and Production of The Berry Diagnostic ToolBlueberries in Arkansas. Arkansas Agricultural By Dr. Marvin PrittsExperiment Station Bulletin. No. 804. Cornell University, Ithaca, NY 14853 Blueberry Production Guide. NE Re- pritts/BerryDoc/blueberry/BBparts.htmgional Ag Engineering Service, Ithaca, NY. 200p. NRAES-55, published by NRAES, Coopera- A companion to the NRAES Production Guidestive Extension, 152 Riley-Robb Hall, Ithaca, NY for strawberries, raspberries and blueberries.14853-5701. 607-255-7654. Blueberry gall midge, Featured CreaturesScott, D.H., A.D. Draper, and G.M. Darrow. 1978. Blueberry Growing. USDA Farm- gall_midge.htmers’ Bulletin No. 2254. US Gov. Printing Office,Washington, DC. 33 p. Blueberry Gardener’s Guide Blueberry Information links Blueberry Electronic Resources on the The Blueberry News World-Wide Web Summer Issue, 2002. Official Newsletter of the Florida Blueberry Growers’ Associa-2002 Blueberry Cultivar Trial–Quicksand tion. Blueberry Page AgNic and MSUAlternative Opportunities for Small Farms: Production Review blueberry.html Commercial Fruit Crops Advisory Program, Blueberry ModuleThe Berry Basket, its precursor, News from the Patch, and Blueberry Times highbush_blueberries.htm Common Blueberry Insect Pests and Their ControlBlueberry Bookmarks Michigan State UniversityMichigan State University Crop Profile for Highbush Blueberry in New JerseyThe Blueberry Bulletin Cooperative Extension CropProfiles/ Disease resistance in blueberry cultivars com- monly grown in KentuckyBlueberry Citation Database State University Extension 24 //BLUEBERRIES: ORGANIC PRODUCTION
  25. 25. Florida’s Commercial Blueberry Industry 207-568-4142 207-568-4141 FAX mofga@mofga.orgFruit Science: Small Fruit Links, Blueberry Managing Plant Diseases with Biofungicidesshtml#partBlue By C. Thomas and Nut Review: Blueberries commhort/2002-11/2002-11-02.htmlMississippi State University Extension Service November 2002. Vol. 1, Issue 11. Integrated Pesthtm Management Program, Pennsylvania Department of Agriculture.Highbush Blueberry ProductionPennsylvania State Agricultural Alternatives Massachusetts Berry Notes, University of Mas- sachusetts Fruit Advisorhighbush_blueberry/highbush_blueberry.pdf index.htmlHighbush Blueberry Michigan Blueberry Growers Association www.blueberries.comThe History of the Lowbush Blueberry Industryin Nova Scotia, 1880–1950 Michigan State University Extension Site History of the Lowbush Blueberry Industryin Nova Scotia, 1950 - 1990 Midwest Small Fruit Pest Management bookindex.htm Ohio State University’ with Kentucky Blueberries Bulletin 861, Chapter 3, Highbush Blueberries.htm The New York Berry News—Tree Fruit & BerryK-Ag Laboratories International Pathology2323 Jackson St., WI 54901 newslett.shtml920-426-0002920-426-2664 FAX North American Blueberry Northwest Berry & Grape InfonetComparison of ‘Gulf Coast’ Blueberry yields Oregon State Universityin Southwest Florida with and without bird nettingBy M. B., T. A. Obreza Main, and G. M. Allen Library of Fruit Science By Paul Evans Organic Farmers and GardenersAssociation (MOFGA) Back issuesP.O. Box 170Unity, ME 04988 //BLUEBERRIES: ORGANIC PRODUCTION PAGE 25