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Organic Alfalfa Production


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Organic Alfalfa Production

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Organic Alfalfa Production

  1. 1. ORGANIC AL.AL.A PRODUCTION AGRONOMIC PRODUCTION GUIDE Abstract: Demands for organic dairy feed are on the rise due to passage of the National Organic Program’s (NOP) organic standards in 2001. Cows producing organic milk must be fed organic hay. This publication discusses basic cultural requirements, insect pest management, diseases of alfalfa that include root and crown diseases and foliar diseases, nematodes, vertebrate pests, weed controls, and economics and marketing. Included are references and resources.By Martin Guerena and Preston Sullivan Table of ContentsNCAT Agriculture Specialists Introduction .................................................... 1July 2003 Basic Cultural Requirements ......................... 2 INTRODUCTION Insect Pest Management ................................ 2 Table 1. Alfalfa Pests and Their ................. Predators ................................................... 3 The rise in demand for organic dairy feed Diseases of Alfalfa .......................................... 8makes alfalfa an attractive crop for some organic Root and Crown Diseases ............................. 8farmers. According to the USDA’s organic stan- Foliar Diseases ............................................. 10dards, cows producing organic milk must be fedorganic feed. The decision to grow organic al- Nematodes .................................................... 11falfa depends on the potential profitability, tak- Vertebrate Pests ........................................... 11ing into account price premium, increased cost Weed Control ............................................... 12of production, markets, and transportation. Fed- Economics and Marketing ............................ 13eral laws regulating the growing, labeling, and Table 2. Estimated Organic Alfalfa Hay of organic products require produc- Production Costs .................................... 14ers to be certified through a private or state Summary ....................................................... 14agency. ATTRA has several publications on the References .................................................... 14topics of organic certification and production. Resources ..................................................... 16Organic Farm Certification & The National OrganicProgram addresses the new federal requirements. An Overview of Organic Crop Production provides a general introduction to or- ganic farming methods and would be considered a prerequisite to starting an organic alfalfa enterprise. The Organic and Sustainable Practices Workbook and Resource Guide for Cropping Systems is rec- ommended especially for producers new to organic farming. These and other relevant ATTRA publications are avail- able in print and on our Web site http:/ /www.attra. ATTRA is the national sustainable agriculture information service operated by the National Center 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. BASIC CULTURAL as rock phosphate and with animal manures, com- post, and other natural fertilizers. Two useful REQUIREMENTS potassium sources are potassium sulfate and potassium magnesium sulfate. Potassium sul- fate must be mined and non-synthetic. OMRI From an agronomic perspective, alfalfa is a (Organic Materials Review Institute, Box 11558,great rotational crop because of its soil condi- Eugene, OR 97440-3758, abilities. In addition, the perennial na- evaluates commercial products for organic pro-ture of alfalfa creates a favorable habitat for many duction. Accepted brand names are Ag Granu-beneficial arthropods, including pollinators and lar, Ogden Sulfate of Potash, Turf Blend™ Greennatural enemies of pests. These natural enemies Grade, Turf Blend™ Mini Granular & Turf Granu-help keep pest levels down in alfalfa and adja- lar, all from Great Salt Lake Minerals; Standardcent crops. Sulfate of Potash & Water Soluble Sulphate of The basic cultural requirements for alfalfa are Potash (SQM North America Corp.), and Ultrasimilar whether it is grown organically or con- Fines Sulfate of Potash (Diamond K Gypsum).ventionally. Seeding rates typically range from K-Mag’s (K-Mag Granular Natural® Crystals™12 to 15 pounds per acre. Seed may be drilled or & K-Mag Standard) generic material is langbein-broadcast into a well-prepared seedbed. Firm ite, and it is OMRI listed. Mined elemental sul-seed-to-soil contact is necessary and may be fur and borax can also be used.achieved with a cultipacker or from the drill Granite dust and greensand are potassium-presswheels. If the seedling stand in the tractor containing minerals used by some organic farm-tire tracks is better than the rest of the field, that ers that release available potassium very a sign the seedbed needs to be firmer. If your They are not cost-effective for large acreages un-shoes sink into the prepared soil past the soles, less mined locally. For additional fertility infor-that too shows the need for a firmer seedbed. mation, request the ATTRA publications Sustain-Plant high quality seed that is inoculated with able Soil Management, Alternative Soil Amendments,the appropriate rhizobium bacteria strain to as- and Manures for Organic Crop Production. Animalsure good nodulation and nitrogen fixation. Se- manure can provide both phosphorus and po-lect a variety that is well adapted to your area tassium economically. It is beneficial to baseand the diseases common there. Detailed pro- manure and compost rates on soil test nutrientduction information on alfalfa growing practices levels, the nutrient content of the manure, and(soil pH, planting dates, seeding rates, and vari- crop needs.eties for specific areas) can be obtained from your Harold Willis’s book How to Grow Great Al-local Cooperative Extension Service. falfa (Willis, 1983) provides a nice overview of Alfalfa requires a deep, well-drained, loamy reduced-input alfalfa production that is largelysoil with a pH between 6.5 and 7.5, free of hard- applicable to organic management. Willis cov-pans and shallow bedrock, to accommodate the ers the basics and goes a step further to discussplant’s long taproot that can penetrate to 20 feet. the relationships among soil biology, alternativeAlfalfa responds well to phosphorus and potas- forage-testing methods, and alternative pest man-sium fertility, but no nitrogen is required, since agement for alfalfa.alfalfa (being a legume) fixes its own nitrogen. Italso uses three to five pounds of boron per acreper year. Adequate lime, phosphorus, and po- INSECT PESTtassium levels should be established prior toplanting, if possible. Base fertilizer application MANAGEMENTrates on soil-test results, crop needs, and the nu- Insect pest management in an organic sys-trient content of the material being applied. Af- tem depends on several factors—including cli-ter the crop is established, only surface applica- mate, beneficial organisms already present in thetions will be possible. Wet soils can cause root area, and hay-cutting schemes. Many types ofheaving during winter and cause more problems insects and mites inhabit alfalfa plantings, yetwith root diseases than well-drained soils. only a few species threaten yields. Proper iden- In an organic system, soil fertility can be main- tification of alfalfa pests as well as their naturaltained with mineral–bearing rock powders such enemies is the first step in successful manage-PAGE 2 //ORGANIC ALFALFA PRODUCTION
  3. 3. ment of pests. Some localExtension service special- Table 1. Alfalfa Pests and Their Predatorsists are familiar with pests gcommon to specific areas va Bu spsand can help with proper ug g ug ar te a rs d B l Bu in B g L etle ira c Widentification. State Exten- to e e s in e rs P itision services along with eda Ey ms sas cew dyb ide nute ras g Pr Bi Da As La La Sp Mi Patheir universities have Alfalfa PestInternet-based informa- ____________________ ____________________ ____________________ ____________________ ____________________ ____________________ ________________ ________________ ________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ Alfalfa Weevil X X X X X X Xtion that can aid with pest __________________________________________________________ Caterpillars X X X X X X Xand beneficial insect iden- __________________________________________________________ Aphids X X X Xtification. Once this infor- __________________________________________________________ X Xmation is known, a scout- __________________________________________________________ Alfalfa Hopper X Xing program with regular Whiteflies X X X X X __________________________________________________________monitoring can help the Potato Leafhoppergrower determine the pest __________________________________________________________pressures and the pres-ence of beneficial insects. When pest pressures fast as the alfalfa. In this situation the plant ma-reach the economic threshold, control actions are tures before weevils can severely damage it.necessary. That is why monitoring is so impor- During a warm spring, or in warmer areas of thetant. For more information on sustainable pest country, larval populations will increase fastercontrol, see the ATTRA publication Biointensive than plant growth, resulting in extensive plantIntegrated Pest Management. damage (Metcalf and Luckmann, 1982). Some farmers find that healthier alfalfa standsAlfalfa weevils are less likely to be damaged by weevils. Some Alfalfa possesses several characteristics that even use refractometers to monitor stand health.favor biological weevil control. First, it is a pe- The refractometer is an instrument that providesrennial plant grown primarily for forage, with a measurement of the soluble solids or sugar in aindividual stands persisting for three to seven plant. A high refractometer reading reflects ayears. This stable system helps populations of high plant sugar level. As sugar levels increase,beneficial organisms increase. Secondly, although plants are better able to resist pest insectsprotein content of alfalfa hay is important, cos- (Behling, 1992).metics are not as important as for fresh vegetable According to Bowman (1992), a mixed plant-and fruit crops. Because alfalfa can tolerate some ing of alfalfa and grasses can reduce weevil anddamage, it is an ideal crop for a pest manage- leafhopper levels in some areas. Harvesting al-ment system that does not completely eliminate falfa in alternate strips has also been shown tothe pest but simply reduces its dramatically increase the number of beneficialpopulation to a modest level. insects occurring in the field (Anon., 1993). Rather than having all of their habitat stripped away from a whole-field harvest, the beneficials from the cut strips can move onto the neighboring remaining strip and continue to find food and shelter. Gen- eralist predators like spiders, damsel bugs, Clemson University - USDA bigeyed bugs, assassin bugs, and lacewing lar- Cooperative Extension Slide Series, vae attack alfalfa weevil larvae. Adult and larval aphid-eating lady beetles have been observed feeding on alfalfa weevil larvae (Kalaskar and Evans, 2001). alfalfa weevil Grazing the spring growth of alfalfa in the late vegetative and early bud stage allows for Spring weather conditions influence the se- nearly all the weevil larvae to be consumed byverity of alfalfa weevil damage. During a pro- the livestock before economic damage occurslonged cold spring, weevil larvae do not grow as (Gerrish, 1997). In a four-year conventional al- //ORGANIC ALFALFA PRODUCTION PAGE 3
  4. 4. falfa study done in Oklahoma (Anon. 1999), re- also live in areas adjacent to these fields. In ar-searchers achieved such good weevil and aphid eas where fall or winter egg-laying does not oc-control from grazing that only one insecticide cur, growers will have to deal with spring adultapplication was necessary throughout the whole weevil migration into the field, and subsequentstudy period. Grazing also aided the control of weeds. Classical biocontrol efforts for alfalfa weevil Some producers use “flaming” to complement in the U.S. have emphasized the introduction oftheir weevil-management program. Field flam- effective parasites into areas where these naturalers that burn LP gas are pulled across the field control agents are rare or absent (Yeargan, 1985).after harvest. The flames are directed at the During the 1980s, the USDA Animal and Plantground to burn off the weevils and their eggs. In Health Inspection Service (APHIS) and its coop-a Kansas study, alfalfa fields were flamed in early erating agencies led the effort to establish alfalfaspring. Flaming reduced the weevil larvae from weevil parasites. In 1991, APHIS completed its2.2 to 0.3 per stem in the first year of the study, ten-year parasite release program.and from 2.7 to 0.9 during the second year of the In the long run, a large population ofstudy (Anon., 1993). There were no yield or qual- beneficials can help provide permanent controlity differences between flaming or several insec- of weevil pests. However, newly introducedticides treatments that were compared. In addi- biocontrol agents often take at least three yearstion to weevil control, flaming alfalfa can reduce to bring their prey under control. Farm manag-weed levels. Early spring flaming controlled 75% ers should therefore try to conserve and fosterof Tansy mustard and shepherds purse and 46% existing populations of beneficials. Anotherof Kentucky bluegrass at a rate of 22 gallons of ATTRA publication that discusses how to con-propane per acre in a California study (Behling, serve beneficials, Farmscaping to Enhance Biologi-2002). In the same study, 11 gallons per acre cal Control, is available on request.controlled 50% of the weeds. Flame Engineering The larval parasites Bathyplectes anurus,(see References for contact information) in Bathyplectes curculionis, and Oomyzus (Tetrastichus)LaCrosse, Kansas, has tractor mounted equip- incertus, and the adult weevil parasitesment and literature to support this practice. Microctonus aethiopoides and Microctonus colesi, in Taking a last cutting of alfalfa as late in the addition to the insect eating fungus Zoophthoraseason as possible may reduce alfalfa weevil dam- phytonomi, are effective natural enemies of theage to the next year’s crop (Metcalf and alfalfa weevil in the eastern U.S. The westernLuckmann, 1982). With most of the foliage gone, U.S. is less favorable to these organisms for bio-the field is less attractive to adult weevils seek- logical control of the alfalfa weevil, except foring a place to lay their eggs during the fall. Late Bathyplectes curculionis, which is very effective incuttings may reduce winter hardiness, however, many areas of the West (Flint and Dreistadt, 1998).due to lack of vegetation to trap and hold snow In northern Utah, research trials were conductedthat insulates the alfalfa crowns and prevents where a sugar solution was sprayed onto the al-them from freezing. The root reserves can be falfa foliage in order to increase the numbers ofdepleted if the alfalfa is cut too late in the sea- the alfalfa weevil parasite Bathyplectes curculionis.son. After the last cutting, the foliage should When sampled two days later, numbers of adultgrow some to allow the roots to store food be- parasitoids were consistently higher in the sugarfore the first killing frost. Another method is to plots than in the control plots (Jacob and Evans,graze off the fall top-growth well after freezing 1998). If aphid or whitefly honeydew is presentweather has set the plants into dormancy, reduc- in a field, sugar sprays to attract the parasitesing weevil egg numbers for next year. Grazing may be redundant. Honeydew can also bring onthe early spring growth before significant weevil sooty mold fungus that can reduce hay quality.damage occurs uses the forage directly and re- Records from the eastern U.S. indicate that whereduces the need for additional control measures. nine out of ten alfalfa fields were sprayed forTo best employ this practice, select alfalfa variet- weevils ten years ago, only one in ten is sprayedies that are adapted for grazing and practice ro- now (Yeargan, 1985). Pest management expertstational grazing or strip grazing. attribute this dramatic decrease in weevil spray- It is important to remember that adult wee- ing to the release of beneficial parasites. The al-vils do not overwinter only in alfalfa fields. They falfa weevil egg predator Peridesmia discus wasPAGE 4 //ORGANIC ALFALFA PRODUCTION
  5. 5. introduced from Europe as a biological control flights in order to Used with permission from University of Californiaagent. It is now known to be established in parts cause confusion orange Statewide IPM Program, Jack Kelly Clark, photographer, http://www.ipm.ucdavis.eduof Georgia, Maryland, North Carolina, South and interruptCarolina, and Tennessee. Data from some of potential mat- sulfur ing.these sites indicate that from 5.6 to 16.7% (7.1average) of overwintering weevil eggs were picture The alfalfapreyed on by P. discus (Dysart, 1988). butterfly (Colias A number of “natural” pesticides may be eurytheme) or Or-used in organic production. Of the botanical in- alfalfa caterpiller butterfly ange Sulphur, assecticides, neem has been proven effective against it is commonlythe alfalfa weevil by acting as a toxicant, insect known, is found throughout the country and isgrowth regulator, and antifeedant. In caged tests considered a pest on alfalfa only when the cli-under field conditions, 2.5 and 5% Neem seed mate is warm and the presence of natural en-suspensions applied four times at weekly in- emies is low. The adults have yellowish or whit-tervals to naturally infested alfalfa com- ish wings with dark borders. The larvaepletely interrupted the larval develop- are velvety green with white lines onment of the pest and increased their sides. The larger larvae (1½yields. (Oroumchi and Lorra, inches) causes the most damage by1993). consuming the entire leaf and de- green foliating the crop. The natural en-Caterpillar Pests lacewing emies that prey on or para- larvae Caterpillars have many sitize the alfalfa cater-natural enemies that usu- pillar include theally keep their numbers predators mentionedbelow damaging levels. above, the larval para-Understanding the biol- sitic wasp Cotesia bigeyed bugogy of beneficial organ- adult medicaginis, and the egg bigeyed bug nymph parasite Trichogrammaisms is important in orderto manage them effectively Used with permission from the Department of Entomology, Ken Gray Extension Slide Collection, and IPMP3.0, semifumantum. Oregon State Universityas pest-control agents. For Cutworms are a prob-example, insect parasitic nematodes like lem in seedling establishment in some alfalfa-Steinerema carpocapsae or insect infecting fungi like growing areas but rarely a problem on established stands. Species are represented by the variegatedBeauveria bassiana require adequate humidity to cutworm, Peridroma saucia; black cutworm,be effective. Other predators include spiders, Agrotis ipsilon; granulate cutworm, Feltiaminute pirate bugs, damsel bugs, bigeyed bugs, subterranea; army cutworm, Euxoa auxiliaris; andassassin bugs, lacewing larvae, and parasitic the Clover cutworm, Scotogramma trifolii. Theywasps. Birds also prey on caterpillars, so do not are active at night, feeding and chewing throughassume that all birds in the field are causing dam- the stems of the seedlings. In the day they bur-age. row underground or under clods, avoiding de- Bacillus thuringiensis is an effective biorational tection. Problem areas are usually found nearpesticide that controls caterpillar pests. Early field borders and in weedier areas. Cutwormsdetection and application during the early devel- have many predatorsopmental stages of the larvae (1st and 2nd in- and parasites thatstar) make these pesticides more effective. Phero- help control theirmone traps are useful tools that indicate when numbers. Some ofmating flights are occurring. Through degree- these parasitesday calculations from mating time, one can esti- and predators canmate egg laying and hatching. For information be purchased oron degree-day calculations contact your local harnessed natu-county Extension agent. Pheromone lures and rally throughdispensers are becoming popular for mating dis- planting or con- granulate Used with permission fromruption of some caterpillar pests. These must be serving habitat for cutworm University IPM Program, Jack Statewide of Californiadeployed and timed with the insects’ mating them. Kelly Clark, photographer, //ORGANIC ALFALFA PRODUCTION PAGE 5
  6. 6. If organically-acceptable pesticide applica- infects beet armyworm. It is available in the prod-tions are necessary, choose one that is least dis- uct Spod-X® LC (Certis). Bacillus thruingiensis onruptive to the natural enemies. The application young worms is effective if application is thor-of rolled oats and molasses baited with Bacillus ough. Laboratory and greenhouse tests showedthuringiensis or nighttime spraying of Bacillus that caffeine boosted the effectiveness of the B.t.thuringiensis are effective strategies. against armyworms up to 900 percent (Morris, Other alternative controls for cutworm include 1995). Like B.t., caffeine interferes with the pests’the use of thyme’s essential oils as a toxicant, digestive and nervous systems. Its use is mostinsect growth regulator, and antifeedant promising against pests that are weakly suscep-(Hummelbrunner and Isman, 2001). Mock Lime tible to B.t. itself. Recipe: dissolve 13 oz. pureor Chinese Rice Flower Bush, Aglaia odorata, in- caffeine in water; add the solution to 100 gallonshibits larval growth and is insecticidal to cut- of standard B.t. spray; apply as usual. (Morris,worms Peridroma saucia and Spodoptera litura, but 1995). Caffeine can be obtained from most chemi-no commercial formulations are currently avail- cal supply houses and is also available in pill formable (Janprasert et al., 1993). Azadirachtin, the from most pharmacies. Organic growers inter-active ingredient in neem, also has similar effects ested in this approach should ask their certifyingon various insects and is used in the form of neem agency about the appropriateness of this treat-cakes to control soil pests in India. Certis USA ment in a certified organic system.produces Neemix® Botanical Insecticide; it’s ac- Many other crops are hosts to armyworms,tive ingredient is Azadirachtin and is registered as are the weeds mullen, purslane, Russian thistle,on alfalfa for cutworm, looper, armyworms, crabgrass, Johnson grass, morning glory,whitefly, and aphids. lambsquarters, nettleleaf goosefoot, and pigweed. Beet armyworm, Spodoptera exigua, and fall These last three are preferred hosts that can servearmyworm, Spodoptera frugiperda, can both feed as indicators of the populations or be managedon alfalfa and on rare occasions cause yield re- as trap crops.ductions. Beet armyworms can cause yield re-ductions in alfalfa if populations are high enough.Armyworms hatch in clusters, and the smallworms spread through the plants over time. Theycut irregular shapes on leaves, skeletonizingthem, trailing frass, and spinning small webs asthey go. The egg clusters are covered with whitecottony webbing, making them easy to spot. Both Alfalfa looper adultthe removal of natural enemies and warm weather Used with permission from the Department of Entomology, Ken Gray Extension Slide Collection,conditions are favorable to outbreaks. and IPMP3.0, Oregon State University Alfalfa looper larvae The Alfalfa looper, Autographa californica, andUsed with permission from the Department ofEntomology, Ken Gray Extension Slide Collection, andIPMP3.0, Oregon State University the Cabbage looper, Trichoplusia ni, feed on leaf areas between veins, causing ragged-edged holes in the leaf and on the leaf margins, but they rarely cause significant damage because of their natu- beet armyworm adult ral enemies. If the enemies are lacking, defolia- beet armyworm larvae tion of alfalfa may become severe. Loopers feed on all the crucifers, crops and weeds, and on melons, celery, cucumbers, beans, Natural enemies are assassin bugs, damsel lettuce, peas, peppers, potatoes, spinach, squash,bugs, bigeyed bugs, lacewing larvae, spiders, the sweet potatoes, and tomatoes. Other hosts in-parasitic flies Archytas apicifer and Lespesia clude some flowers, like stocks, snapdragons, andarchippivora, and the parasitic wasps tobacco. Some weed hosts include lambsquarter,Trichogramma ssp. Hyposoter exiguae, Chelonus dandelion, and curly dock.insularis, and Cotesia marginiventris. Nuclear poly- In addition to the natural enemies mentionedhedrosis virus is a disease-producing virus that above, many parasitic wasps also attack loopers,PAGE 6 //ORGANIC ALFALFA PRODUCTION
  7. 7. including Trichogramma pretiosum, Hyposoter leafhoppers are about 1/8 inch long, green in-exiguae, Copidosoma truncatellum, and Microplitis sects with wings that when at rest resemble pupbrassicae. The parasitic fly Voria ruralis also con- tents. Immature leafhoppers are called nymphstributes to the loopers’ natural control. and look like wingless adults. Both the adultTrichoplusia ni NPV (nuclear polyhedrosis virus) and nymph feed on sometimes responsible for sudden decline in Planting grasses in the alfalfa stand is a cul-looper population, especially after a rainfall. Ba- tural practice that reduces leafhopper damage.cillus thruingiensis is effective when the problem Grass repels leafhoppers, and the females areis detected early. less likely to lay eggs in mixed stands. A Mis- souri study (Bowman, 1992) showed leafhopperAphids reductions of 54 to 76% over a three-year period Aphids are piercing and sucking insects from in a grass-alfalfa mixture as compared to purethe order Hemiptera that feed on alfalfa, result- alfalfa stands. The University of Minnesota Ex-ing in stunting, leaf curling or distortion, leaf tension has a chart that compares alfalfa heightdrop, and yellowing of the plant. They excrete to number of leafhoppers per sweep to aid inhoneydew, which is a food for sooty mold fun- determining when to take action to prevent eco- gus that contaminates alfalfa nomic injury. The Web site is: http:// and lowers its quality. On the positive side, honey- cropsystems/DC3516.html#plh. dew can serve as a food source for beneficial in- Three cornered Alfalfa Hopper sects. The principal The three cornered Alfalfa Hopper, Spissistilus aphids that attack alfalfa festinus, is a major pest in the South. It is another are Pea aphids, piercing and sucking, triangular green insect that damsel bug Acyrthosiphon pisum; Blue feeds on alfalfa stems and leaves. It is also nymph alfalfa aphids, found on vegetables, soybeans, peanuts,Used with permission from the Department of Acyrthosiphon lady beetle adult other legumes, grasses, small grains, sun-Entomology, Ken Gray Extension Slide Collection, andIPMP3.0, Oregon State University kondoi; Spotted flower, tomatoes and weeds. On alfalfa,alfalfa aphids, Therioaphis maculata; Al- it girdles the stem during feeding,falfa aphids, Macrosiphum creelii; Clover causing it to become brittle and fallaphid, Nearctaphis bakeri; Cowpea aphid, over. Natural enemies include theAphis craccivora; Green peach aphid, bigeyed bug and damsel bug. TheMyzus persicae; and the Potato aphid bigeyed bug has been observed caus-Macrosiphum euphorbiae. Aphids have Used with permission from the Department of ing the highest mortality (90-100%) ofmany natural enemies that usually keep Entomology, Ken GrayState University Collection, 1st and 2nd nymphal stages, while the and IPMP3.0, Oregon Extension Slidetheir numbers down. These include syr- damsel bug attacked all nymphal stagesphid flies, aphid flies, bugs (minute pirate bugs, of the three cornered Alfalfa Hopper (Medal, etdamsel bugs, bigeyed bugs), lady beetles, sol- al., 1995).dier beetles, lacewing larvae, insect eating fungi,and several parasitic wasps. WhitefliesPotato Leafhopper Whiteflies are small piercing and sucking in- sects. The adults resemble small moths, and the The potato leafhopper is a serious pest of al- nymphs look like scale insects. They are occa-falfa in the eastern U.S. Like aphids, they pierce sional pests on alfalfa in the Southwest. Whenstems and suck plant juices, disrupting plant populations are large, they can stunt, cause yel-functions. The symptoms are lowing, or give a mottled appearance to thestunting and yellowing plants. In extreme cases they can cause defolia-of the crop, but once Used with permission from University tion. Like aphids, whiteflies also secrete honey- of California Statewide IPM Program, Jack Kelly Clark, photographer, http://the symptoms are dew that facilitates sooty mold development andvisible, the damage lowers alfalfa’s quality. Whiteflies’ natural en- www.ipm.ucdavis.eduto the crop is done. emies include lady beetles, lacewings, minuteScouting is critical pirate bugs, bigeyed bugs, predatory mirid bugs,to prevent this from Macrolophus caliginosis, the predatory beetlehappening. The adult potato leafhopper Delphatus pusillus, parasitic wasps Encarcia formosa //ORGANIC ALFALFA PRODUCTION PAGE 7
  8. 8. and Eretmocerus eremicus, and the insect eating find a niche. Applying compost teas adds ben-fungus Beauveria bassiana. eficial microorganisms to the leaf, making it more If populations are not being controlled by difficult for diseases to become established. Fornatural enemies, an organically accepted pesti- more information on foliar disease controls, seecide application is advisable. Make sure to use the ATTRA publications Notes on Compost Teas,products that are least disruptive to the natural Use of Baking Soda as a Fungicide, Organic Alterna-enemies, and check with your certifying organi- tives for Late Blight Control on Potatoes, and Pow-zation on which products are acceptable. The cost dery Mildew Control on Cucurbits.of the application, the effectiveness of the pesti-cide, and the price of the commodity all have tobe considered. Insecticidal soaps, horticultural ROOT AND CROWNoils, and botanical insecticides like pyrethrum(PyGanic®), neem (Neemix®), sabadilla (Red DISEASESDevil Dust®, Natural Guard®, Veratran D®), and Damping off is caused by soil fungi such asRyania have been used on piercing and sucking Fusarium, Pythium, Phytophthora, and Rhizoctonia.insects with varying success. Check with your They attack germinating seeds and young seed-certifier before applying any of these products. lings by infecting emerging roots and cotyledons. DISEASES O. Extremely wet conditions are ideal for damping off to develop. Planting deep in cool soil delays AL.AL.A emergence and makes the seedlings more sus- ceptible to disease. Some work has been done on biological control of damping off in alfalfa us- Diseases in plants occur when the pathogen ing Streptomyces (Jones and Samac, 1996) and Ba-is present, the host is susceptible, and the envi- cillus cereus (Handelsman,, 1990).ronment is favorable for the disease to develop. Phytophthora root rot (PhytophthoraEliminating any one of these three factors will megasperma) is a water-mold fungus that thrivesprevent the disease. Organisms responsible for in saturated, poorly drained fields. Good landalfalfa diseases include fungi, bacteria, nema- preparation, careful irrigation management, andtodes, and viruses. If these organisms are present, the use of resistant varieties are cultural prac-manipulation of the environment and the host to tices that can keep this disease under control.make it less susceptible help to better manage After a hay cutting, irrigation management is criti-diseases on alfalfa in a sustainable manner. If cal, since older plants that have their shoots re-known diseases are prevalent in your area, check moved showed significantly more Phytophthorawith your seed salesman and request tolerant or damaged than younger plants under the sameresistant varieties. saturated conditions (Barta and Schmitthenner, Soil health and management is the key to suc- 1986). Symptoms include yellowing and defolia-cessful control of plant diseases. A soil with ad- tion of older leaves, wilting, and slow growth ofequate organic matter can house large numbers plants. Infected plants pull up easily, with rootsof beneficial organisms such as bacteria, fungi, and crowns breaking off due to rot. Roots mayamoebae, nematodes, protozoa, arthropods, and exhibit red, brown, or black lesions, but they canearthworms that in conjunction deter harmful recover if conditions that favor this pathogenfungi, bacteria, nematodes, and arthropods from cease.attacking plants. These beneficial organisms alsohelp to create a healthy plant that is able to resistpest attack. For more information, see theATTRA publication Sustainable Management of Soil-Borne Plant Diseases. The leaf surface can also host beneficial or-ganisms that compete with pathogens for space.A disease spore landing on a leaf surface has tofind a suitable niche for it to germinate, penetrate,and infect. The more beneficial organisms on the © 2003 OSU, used with permission of Plant and Soil Sciences Department, Oklahoma State Universityleaf, the greater the competition for the spore to examples of alfalfa with Phytophthora root rotPAGE 8 //ORGANIC ALFALFA PRODUCTION
  9. 9. (Stagonospora meliloti) Stagonospora Rot healthy plants, and they will re-grow more slowlyis a fungal disease that attacks the crown and after harvest. A cross-section of the root will dis-roots of the alfalfa plant. Symptoms on the leaves play ring-like discolored vascular tissue that in-are irregular tan spots with brown borders. As terferes with water transport. The bacteria ini-the spots enlarge they form concentric rings, with tially enters the plant through wounds causedsmall, round black spots forming in the center of by harvesting, insects, or nematodes. Culturalthe tan spots. The spores are released from these practices include the use of resistant varieties,small black spots and are dispersed by splashing avoid harvesting when plants are wet, harvestwater from rain or irrigation. Symptoms on a healthy stands first, and cleaning equipment whencross section of the tap root consist of reddish changing fields.spots on the tissue. There are no known resis- Sclerotinia rot (Sclerotinia sclerotiorum or S.tant varieties. trifoliorum) attacks alfalfa plants under cool and Rhizoctonia (Rhizoctonia solani) is a fungus wet conditions. The fungus attacks the stems and crowns, eventually wilting the plant and pro-that creates necrotic spots or cankers on roots, ducing a soft rot of the infected tissue. If condi-crowns, and stems and will cause blight on leaves. tions are favorable, white fungal bodies (myce-It is promoted by wet soil conditions and high lium) are visible. They then produce the blacktemperatures. Root damage in established plants resting spore structures (sclerotia) on the infectedappears as round and oval lesions (cankers) on tissue and surrounding soil. The sclerotia, whichthe taproot. During the summer when the patho- survive in the soil, germinate to produce smallgen is active, the lesions are brown to tan in color, structures called apothecia. The apothecia re-while during the winter the lesions are black. lease tiny spores (ascospores) that land on theThere are some alfalfa varieties that are tolerant. plants and begin the infection cycle. The sclero- Anthracnose (Colletotrichum trifolii) is tia can also produce the mycelium that can infectcaused by a fungus that develops in warm, hu- the plant directly. Where this disease has been amid weather. Spores are splashed from infected moderate problem, the use of resistant varietiesplants to healthy ones during rainfall or by irri- is recommended. Deep plowing will bury scle-gation. Diamond-shaped lesions with dark bor- rotia, but this resting spore can be viable for manyders appear on the stems, and the upper por- years if the environment is dry. Eventually the disease remerges after a few seasons. Solariza- tions of these stems will wilt and tion of soils infected with Sclerotinia sclerotiorum become hook shaped. The fo- reduced the viability of the sclerotia at 5cm, 10 liage on these stems will be-© 2003 OSU, used with permission of Plant and Soil Sciences cm, and 20 cm after 15 and 30 days and nullified come clorotic (loose green them after 45 days (Cartia and Asero, 1994). In Department, Oklahoma State University color) and die. Alfalfa va- alfalfa seed production, autumn burning of in- rieties resistant to an- fected alfalfa fields reduced sclerotia by more than thracnose are available. 95% and increased seed yields by 43% in Wash- Induced resistance to ington state (Gilbert, 1991). Colletotrichum trifolii has .usarium Wilt (Fusarium oxysporum sp. been achieved in al- medicaginis) causes the leaves and stems of the falfa by inoculating alfalfa plant to yellow and wilt, eventually kill- the plant with other ing the plant and turning it white. The tap root Colletotrichum species examples of plants with cross section will show a reddish-brown discol- such as C. malvarum, anthracnose oration. In an infected which causes anthra- field only somecnose on hollyhock (Althaea rosea), and C. plants willgloeosporioides (O’Neill, Elgin, and Baker, 1989). show symp-Equipment that has been used to harvest alfalfa toms. In in-infected with anthracnose should be disinfected fested soilsbefore moving to other fields. © 2003 the fungus Bacterial Wilt (Corynebacterium insidiosum). OSU, used with permission may persistPlants infected with this bacterium exhibit yel- of Plant and Soil Sciences Department, for five yearslowish, stunted leaves and shorter stems than Oklahoma State University example of fusarium wilt or more. Infec- //ORGANIC ALFALFA PRODUCTION PAGE 9
  10. 10. tion is through wounds on the roots caused by ish. Once the disease becomes systemic it willinsects or mechanical injury, and through the tiny stunt the plant, thickening the stems and distort-secondary and tertiary feeder roots. Cultural con- ing leaves. The initial infection occurs as sporestrols consist of resistant varieties, reduction of germinate on wet leaves. Once the weatherplant stress through proper irrigation and nutri- warms up and the environment becomes drier,tion, avoidance of mechanical injury, clean har- the disease will cease until the conditions for itsvesting equipment, and rotation with grains or development once again become favorable. Re-grass forages. Inoculation of alfalfa seedlings with sistant varieties, seeding in spring instead of au-vesicular arbuscular mycorrhizal (VAM) fungi tumn, and early harvest in spring are cultural(Glomus spp.) produced a lower incidence of wilt practices that may reduce the severity of this dis-than non-mycorrhizal plantings, and the number ease.of Fusarium and Verticilium spores were lower in Stemphylium Leaf Spot (Stemphyliumsoils inoculated with VAM fungi than in non-my- botryosum) is a unique fungal disease in that vari-corrhizal soil (Hwang, Chang, and Chakravarty, ous biotypes display different symptoms on al-1992). falfa in different parts of the U.S. In the West, Phymatotrichum Root rot (Phymatotrichum spots are irregular in shape, tan in color with darkomnivorum) is commonly known as Texas root borders, and do not increase in size. Cool, wetrot and infects more than 2000 species of broad- weather favors this biotype’s development. Inleaf plants. This fungus is active in alkaline soils the East and Midwest the spots grow and coa-and prefers the hot summer temperatures of lesce to form a larger blighted area, often with aTexas and the Southwest. Infected plants will series of concentric rings. Heavily infested plantsexhibit water stress and wilt during the summer, can lose their leaves and die. This biotype pre-and when pulled will break off below the crown. fers warm temperatures and is more of a threat The vascular system in the summer and early fall. Resistant varieties© 2003 OSU, used with permission of Plant and Soil Sciences Department, Oklahoma State University near the crown and early harvest are recommended to deal with will be brown this disease. and the roots Black Stem (Phoma medicaginis) appears as rotten. The in- small black or brown spots on leaves and stems fected area in of alfalfa. As the fungal disease progresses the an alfalfa field spots coalesce into larger spots that cover the will grow out- leaves and stems. Lesions on the stem may girdle wards as the dis- Texas root rot ease spreads, form- the plant, turning the leaves yellow and eventu- ally killing the plant. The organism may also in-ing a ring pattern. After humid and rainy weather, vade crown tissue and cause crown rot. Goodtan spore mats 8 to 12 inches in diameter may soil fertility and harvesting at regular intervalsform on the soil near the edge of these ring pat- will increase plant vigor and help plants tolerateterns. Extended rotation with corn, sorghum, or the effects of the disease.other grains may reduce the severity of the dis-ease. Common Leaf Spot (Pseudopeziza medicaginis) develops small brown to black- .OLIAR ish spots on alfalfa leaves. In the center of these dark spots are the fungal fruit- DISEASES ing bodies that disperse spores dur- ing wet weather. When conditions are right, this disease can spread Downy Mildew (Peronospora quickly through a field. Infectedtrifoliorum) is a foliar disease that leaves will have many spots, turnoccurs when weather conditions are yellow, and fall off the plant. Thiscool and wet. It appears as a gray- disease effects the quality andish-white, powdery growth quantity of the forage. Once the(spores) on the bottom side of the weather warms and dries, the dis-leaves. The corresponding top por- example of downy mildew ease cycle stops, but older leavestion of the leaves will be yellow- © 2003 OSU, used with permission of Plant and Soil Sciences Department, Oklahoma State University and debris will provide inoculumPAGE 10 //ORGANIC ALFALFA PRODUCTION
  11. 11. once it cools. Resistant varieties and early har- tion water from entering clean fields. Wind-blownvest are recommended cultural controls. In a con- dry alfalfa also has the potential to transport al-ventional alfalfa study, adequate potassium fer- falfa stem nematodes to clean fields. Other cul-tilization (65 lbs/a.) was shown to reduce the se- tural practices are using resistant varieties, cleanverity of common leaf spot disease on alfalfa certified seed, and crop rotation for two to three(Grewal and Williams, 2002). years with non-host crops such as small grains, corn, cotton, beans, or tomatoes. NEMATODES Root Knot Nematodes (Meloidogyne spp.) can cause galling, excessive branching of lateral Plant parasitic nematodes are microscopic roots, and stunt growth of stems and leaves. Rootworm-like animals that attack plant roots, creat- knot galls are distinguished from nitrogen-fixinging galls that limit water and nutrient uptake. nodules by their refusal to dislodge from the rootThis results in weakened plants that are suscep- when rubbed. This nematode is sometimes im-tible to further pest attack. Nematode control is plicated in interaction with other pathogens suchessentially prevention, because once a plant is as Phytophthora root rot, Fusarium wilt, and Bac-parasitized it is impossible to kill the nematode terial wilt. Cultural controls include the use ofwithout also destroying the host. The most sus- resistant varieties and irrigation and nutrienttainable approach to nematode control will inte- management to avoid plant stress. Crop rota-grate several tools and strategies, including cover tion does not provide adequate control becausecrops, crop rotation, soil solarization, least-toxic of the wide range of hosts that the root knot nema-pesticides, and plant varieties resistant to nema- tode attacks.tode damage. These methods work best in the Root Lesion Nematodes(Pratylenchus spp.)context of a healthy soil environment with suffi- have a wide range of hosts and are most active incient organic matter to support diverse popula- sandy soils. The above ground symptoms cantions of microorganisms. A balanced soil eco- be confused with other disorders that cause stunt-system will support a wide variety of “biological ing and nutrient deficiencies. The roots exhibitcontrol” organisms that will help keep nematode reduced growth and dark brown or black lesionspest populations in check. For more informa- on the root epidermis. These lesions may coa-tion on nematodes and their controls, request the lesce and turn the entire root dark brown or black.ATTRA publication Alternative Nematode Control. Attacks by the root lesion nematode can allow Alfalfa Stem Nematode (Ditylenchus secondary infection by other disease organisms.dipsaci) is one of the few species of nematodes Root lesion nematode resistant varieties of alfalfathat feeds on above-ground plant parts. Alfalfa and fallowing for a couple of months followingsymptoms include sections of stunted plants with residue incorporation are suggested cultural con-distorted leaves. Stem internodes are short and trols.swollen, and some stems may turn white. Thesesymptoms appear on spring regrowth or afterthe first or second cutting of an established field. VERTEBRATE PESTSControl methods include sanitation, such as clean- Alfalfa provides a very desirable habitat foring equipment from infected fields before mov- several mammal pests. Besides feeding on theing to other fields, and preventing runoff irriga- nutrient-rich succulent leaves, stems, and roots, mammals may burrow into levees and ditches and damage irrigation systems and harvesting equipment. Mammal pests of alfalfa include mice,© 2003 OSU, used with permission of Plant and Soil Sciences Department, Oklahoma State University gophers, ground squirrels, rabbits, and deer. Proper identification of the species involved is critical, because control measures differ with each one. Assistance in correctly identifying the ani- mals causing the damage is available through the local Extension service. .ield Mice (Mictotus spp), also called stem nematode damage meadow voles, dig short, shallow burrows and //ORGANIC ALFALFA PRODUCTION PAGE 11
  12. 12. make underground nests, creating trails about wildcats is recommended if rabbits are a persis-two inches wide that lead from their burrows to tent problem. Modification of the rabbits’ envi-surrounding areas of the field where they feed. ronment by removing debris and vegetationControl measures consist of cutting the surround- where they hide is another cultural control. Re-ing vegetation in ditches and adjacent fields, trap- pellents, frightening devices, traps, hunting, andping (which can be impractical when populations domestic dogs and cats, can also contribute toare high), the use of ammonium-based repellents reducing rabbit numbers.(check with certifier), and habitat creation for rap- Deer and other large grazers such as elk andtors and mammal predators such as coyotes, antelope can cause significant damage to alfalfafoxes, wildcats, weasels, and shrews. plantings. Several methods to control these large Gophers (Thomomys spp.) are burrowing ro- mammals have been used with varying levels ofdents that feed mostly on underground plant success. Odor repellants and devices that pro-parts, with alfalfa being one of their preferred duce periodic explosions can be effective for lim-foods. Besides weakening or killing the plants, ited periods, but are not long-term solutions be-they also damage irrigation ditches and borders. cause the animals grow accustomed to them.The mounds of soil they push up from their bur- Fencing is probably the most effective method torows also bury other plants and cause obstacles protect large fields. The use of guard dogs, anfor the harvesting equipment. Non-toxic controls odor repellent, and no treatment were comparedconsist of trapping, flooding the burrows, sur- at a pine seedling plantation in Missouri for pro-rounding a field with plants that repel gophers, tection against grazing deer. The dogs were asuch as gopher spurge (Euphorbia lathyrus) and better deterrent than Hinder (odor repellent) orcastor bean (Ricinus communis). Depositing preda- no treatment. Browse rates averaged 13, 37, andtor urine, pine oil, or any other foul smelling sub- 56%, respectively, for dogs, Hinder, and no treat-stances in the burrows has been reported to pro- ment during the three-year study. Browsed seed-vide temporary control. The use of barn owl lings were generally heavier in weight on plotsperches to attract these predators has been suc- protected by dogs, suggesting that browsing se-cessful in controlling gophers in California. On verity was also reduced (Beringer, et al., 1994).average, a barn owl can eat 155 gophers per year For more information on controlling deer, request(Power, 2003). Propane devices that ignite in- the ATTRA publication Deer Control Options.jected gas, causing the burrows to explode, arereported effective in reducing populations tem-porarily. Check with your certifier before using WEED CONTROLthis method. Additional treatments are neces- Strategies for non-herbicidal weed control in-sary, depending on the length of the season. clude interseeding alfalfa with annual or peren- Ground Squirrels (Spermophilus spp.) dam- nial grasses, harrowing, grazing, and using nurseage alfalfa by feeding on leaves, stems, and crops during establishment. Additionally, any-crowns. Their burrows damage plant roots and thing that can be done to help the crop grow bet-irrigation levees and create obstacles for field ter and thus compete with weeds better shouldequipment. Controls include trapping, remov- be done. These practices include adequate limeing rocks and stumps at the edges of fields that and fertility, planting well-adapted varieties,provide a desirable habitat, deep tillage to dis- choosing a well-drained site, rotating alfalfa withrupt the burrow system, and shooting. Repel- annual crops to interrupt the buildup of certainlents such as pepper spray, mothballs, and preda- weeds, and cutting alfalfa at the proper growthtor urine have been used around plants and bur- stage. For spring-seeded alfalfa, a nurse crop ofrows with varying success. Again, check with any one of the early-maturing spring grains willyour certifier before using any of these. help suppress weeds during the alfalfa’s estab- lishment period. Peas or oats are common com- Rabbits (Sylvilagus spp.) and Jackrabbits or panion crops intersown with alfalfa. Seeding al-Hares (Lepus spp.) can be kept out of alfalfa fields falfa stands with annual grass crops such as oatswith fencing that is at least four feet high and reduces weed pressure through direct competi-buried at least six inches. Habitat establishment tion. These mixed stands of alfalfa and oats makeor conservation to encourage natural enemies good hay for the horse market. On-farm studiessuch as hawks, owls, eagles, coyotes, foxes, and in Wisconsin (Bowman, 1992) during 1988 andPAGE 12 //ORGANIC ALFALFA PRODUCTION
  13. 13. 1989 showed only 1% weed infestation in a production systems. A thick alfalfa stand willbrome-alfalfa-trefoil mix. A timothy-alfalfa mix suppress weed growth, provided that weeds dohad 14% weeds (mostly grasses), and an not become a problem during the establishmentorchardgrass-alfalfa mix had 21% weeds—again, phase. Stands tend to thin out after four to fivemostly grasses. Quackgrass often invades aging years, however, because alfalfa contains a sub-alfalfa stands. In these studies, the brome- and stance toxic to its own seedlings. Weed controlorchardgrass-mixed plots were quack-free can become especially difficult at this point.through the second year of the study. Dairies Weed control during the establishment phaseusually require pure alfalfa hay, so the economic is critical. Failure to have weeds under controlimpact of selling mixed hay vs. pure alfalfa should following a planting will result in crop noted. The grade of the alfalfa hay dictates Fall plantings generally result in fewer weed prob-price, with “Supreme” demanding the higher lems than those done at other times of the yearprice, followed by “Premium”, “Good,” “Fair,” (Mortenson, 1992). After primary tillage, the fieldand “Utility.” This system is also used for mixed can be allowed to sit for 7 to 10 days and thehay, but a “Premium” mixed hay price may be weed germination observed. Two or more discingreduced to the price for a “Good” alfalfa hay, if passes may be necessary to reduce germinatedthere is interest in the mixed hay. For more in- weed seed. After that, apply compost, boron,formation on feed quality, check the University and other nutrients the soil test calls for and tillof Nebraska Cooperative Extension Web page at: into the soil. Another week or so can be allowed to check for weed growth. If none, the field isg915.htm. ready to plant. For a mixed stand, reduce the alfalfa seedingrate to 8 to 10 pounds per acre in combinationwith a reduced rate of perennial grass seed. If ECONOMICS ANDan oat or barley nurse crop is to be used, seed 1to 2 bushels of oats (32 to 64 lbs) or 1 bushel of MARKETINGbarley (48 lbs) per acre along with the alfalfa and Organic dairies are the primary buyers of or-perennial grass mixture. For best alfalfa estab- ganic hay. Organic soybeans can serve as a sub-lishment, harvest the small grain nurse crop in stitute protein source for organic dairies. Underthe boot stage, or just before it forms a seed head. these circumstances, organic hay prices mayCaution must be taken during fall seeding in dry- move parallel to the price of organic conditions, because the small grains use the Much of the organic soybean market is in Japan,moisture faster than the alfalfa seedlings, result- and when they are paying $20 per bushel for soy-ing in poor stand establishment. beans, few beans are going for animal feed. Pre- It is important to get a good stand established miums for organic hay are, at a minimum, 10 toduring the first year because of autotoxicity con- 15% (Lehnert, 1998). Premiums for organic haycerns. Mature alfalfa (more than one year old) may go as high as 40 to 50% when few substi-produces a chemical called medicarpin that is tutes exist (Lehnert, 1998). As with any hay mar-toxic to younger plants. This chemical is concen- ket, quality affects price. Moldy or over-maturetrated on the leaves and stems, so reseeding af- hay will bring lower prices.ter harvest is recommended on mature plantings. Budgets for organic alfalfa hay production canMedicarpin is water soluable; a good rain or irri- be found at most county Extension offices. Thegation can leach this chemical past the root zone. figures presented in Table 2 are adapted from aFor more information on conventional budget for an or-alfalfa autotoxicity, visit ganic farming situation. Thethe America’s Alfalfa Web two primary differences be-site at: http:// tween organic and alfalfa budgets will be fertilizerchapters/autotoxicity.htm type (manure vs. commercial Rotations including fertilizer) and pest control (or-short-duration alfalfa (2–3 ganic and biological pesticidesyears) are appropriate for vs. conventional pesticides).sustainable and organic © 2003 The actual figures will vary //ORGANIC ALFALFA PRODUCTION PAGE 13
  14. 14. Table 2. Estimated Organic Alfalfa Hay Production Costs Item Unit Quantity Price $/ac Your Farm__________________________________________________________________________________________ Variable Expenses__________________________________________________________________________________________ Fertility (Manure) ton 10 12.00 120.00__________________________________________________________________________________________ Lime ton 1 18.00 18.00__________________________________________________________________________________________ Insect Control (approved chem.) acre 155.00 155.00__________________________________________________________________________________________ Twine bale 140 0.04 5.79__________________________________________________________________________________________ Machinery__________________________________________________________________________________________ Fuel acre 1 2.76 2.76__________________________________________________________________________________________ Oil and filter acre 1 0.41 0.41__________________________________________________________________________________________ Repairs and Maintenance acre 1 21.72 21.72__________________________________________________________________________________________ Labor hour 5.62 8.00 44.99__________________________________________________________________________________________ Interest on operational capital (6 mo.) acre 10% 0.10 18.84__________________________________________________________________________________________ Total Variable Expenses 387.51__________________________________________________________________________________________ Fixed costs__________________________________________________________________________________________ Establishment costs (25%/year) acre 1 35.07 35.07__________________________________________________________________________________________ Machinery__________________________________________________________________________________________ Depreciation acre 1 21.05 21.05__________________________________________________________________________________________ Interest on operation capital (6 mo.) acre 1 30.22 30.22__________________________________________________________________________________________ Housing and Insurance acre 1 2.13 2.13__________________________________________________________________________________________ Total Fixed Costs 88.47__________________________________________________________________________________________ Total Budgeted Expenses 475.98 Table adapted from: region to region and from farm to farm. pers and aphids are generally controlled by aThe blank space to the right of each row is pro- number of natural enemies that are encouragedvided for your estimated costs. One useful Web to stay in the field. Several diseases also plaguesite where conventional alfalfa budgets can be alfalfa, including various root and crown rots,found is wilts, and foliar diseases most of which can bebudgets.html#forage. controlled by proper field dranage. Alfalfa also attracts several rodents, rabbits, and deer that SUMMARY consume the crop and reduce yields. A variety of organic methods to limit losses associated with Demand for organic dairy feed makes alfalfa these pests are available. Weed control strate-an attractive crop for some organic farmers. Fer- gies include interseeding the stand with grasses,tility sources include a variety of mined mineral- harrowing, grazing, and using nurse crops dur-bearing rock powders, animal manure, and com- ing establishment. Adequate lime and soil fertil-post. Alfalfa can be attacked by a variety of in- ity allow the stand to compete with weeds. RE.ERENCESsect pests including alfalfa weevils, various cat-erpillars, aphids, and leafhoppers. Controls foralfalfa weevil include flaming in the fall, plantinga mixture of alfalfa and a grass, and strip har- Anon. 1999. Early spring grazing as a compo-vesting the crop to maintain populations of ben- nent of alfalfa integrated pest manage-eficial insects. Caterpillars can be controlled by ment. Midwest Biological Control News.several different insecticides derived from the April. p. 6.fungus Beauveria bassiana, the bacteria Bacillus Anon. 1993. Burning helps control alfalfathuringiensis, or several egg parasites that are en- weevils. Hay and Forage Grower. May,couraged from natural populations or released p. 22.into the field in substantial numbers. Leafhop-PAGE 14 //ORGANIC ALFALFA PRODUCTION