Evaluation of Corn Varieties for Certified Organic Production Crawfordsville Trial, 1998

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1 Evlution of Corn Vrieties for Certified Orgnic Production Crwfordsville Tril, 1998 Dr. Kthleen Delte, ssistnt professor, Depts. of Horticulture & Agronomy Kevin Vn Dee, frm superintendent, Southest Reserch nd Demonstrtion Frm Kerry Tylor, reserch ssocite, Depts. of Horticulture & Agronomy Introduction Orgnic frming hs incresed to $4.2 illion industry in the U.S. nd continues to expnd pproximtely 2% nnully. In Iow lone, orgnic crege for ll crops hs incresed from 13, in 1995 to 12, in Orgnic corn production in 1997 ws reported t 9,92 cres. Interntionl demnd for orgnic products, prticulrly from the Jpnese nd Europen mrkets, is lso on the rise. Frmers interested in trnsitioning some or ll of their lnd into orgnic production require informtion on the est mngement prctices for these systems. Once the trnsition is complete, comprle yields to conventionl systems cn e otined. In ddition, orgnic products grner 2-3% premium price in the mrketplce, with orgnic corn, for exmple, verging 2% premium price over conventionl corn in Soil helth, mintined through crop rottions, orgnic mtter dditions (mnure/compost), nd cover crops, hs een the sis of successful orgnic frming. In the first yer trils growing corn under orgnic conditions, we exmined the performnce of four vrieties, using loclly produced, inexpensive, renewle resource (hog mnure) for fertiliztion, nd mechnicl methods for weed control (s required for certified orgnic production). Mterils nd Methods Plots previously plnted to soyens t the Southest Reserch nd Demonstrtion Frm (SERF) were identified for this study. Soil smpling in the fll of 1997 chrcterized the soil s shown in Tle 1. Tle 1. Pre-plnt soil chrcteristics t the SERF Orgnic Corn Tril, Soil Chrcteristic Amount Orgnic Mtter 4.4% ph 6. Buffer ph 6.45 P 2 ppm K 184 ppm Soyen cyst nemtode eggs 5 eggs/1 cc soil Plots were field cultivted for seeded preprtion on My 13 nd gin on My 21, Untreted corn seed ws plnted t 1.75 in. depth on My 21 in 3-in. rows. Four replictions of four vrieties were plnted t popultion of 27,7 plnts/cre in 2 x 6 ft. plots. Vrieties included the following Pioneer hyrids:,,, nd. The following informtion is excerpted from Pioneer literture:

2 Pioneer hyrid A 17-dy hyrid with very good er mold resistnce, rittle stlk resistnce, nd drought tolernce with moderte tolernce to gry lef spot. This hyrid should provide excellent silge yields, energy, nd digestiility. This vriety is lso ville s high oil hyrid in One drwck to this hyrid is its susceptiility to nthrcnose stlk rot. Pioneer hyrid An exceptionlly high yielding 17-dy hyrid with strong stlks, superior stygreen, outstnding drought tolernce, nd moderte gry lef spot resistnce. This vriety responds well to higher plnting popultions. Pioneer hyrid A very high yielding 18-dy hyrid tht is widely dpted nd stle. This vriety hs strong drought tolernce, exceptionl drydown, nd is n excellent choice for silge. Some concerns with this hyrid re its susceptiility to nthrcnose stlk rot nd its slightly lower rte of emergence. Pioneer hyrid A 112-dy hyrid with exceptionl yield potentil. Its strong gry lef spot resistnce, excellent stlk qulity, exceptionl stygreen, superior test weight, nd dependle erly growth mkes it n excellent choice for gry lef spot chllenged res. This hyrid lso demonstrtes exceptionl silge yield potentil with excellent redily ville energy nd digestiility. Fertiliztion ws provided through liquid hog mnure tht ws rodcst t rte of 3,5 gl/cre nd incorported on My 13, This ppliction period corresponded with the requirement for rw mnure to e pplied t lest four months prior to hrvest for gronomic crops. Anlysis of this mnure included 39 pounds of nitrogen per 1, gllons of mnure to supply pproximtely 136 pounds of N/A. No insecticides, fungicides or hericides were pplied in keeping with orgnic stndrds. Weeds were mnged through two rotry-hoeings (My 27 nd June 4) nd one row cultivtion on June 25. A core set of mesurements ws tken on 1 plnts per plot (totl of 4 plnts per vriety) for crop stnd counts (July 1), insect dmge (July 1), nutrient uptke (er-lef tissue content (July 2) nd stlk nitrte content (Octoer 5). The middle three rows (7.5 x 6 ft.) were hrvested on Octoer 9, 1998, with comine equipped with scle to quntify yields. All mesurements were sujected to nlysis of vrince nd Fisher's PLSD test.

3 Results nd Discussion Corn performed very well under orgnic conditions, with yields rnging from ushels/cre. Averge production for ech vriety is presented in Figure 1. There were no significnt differences mong the four vrieties (ANOVA, P=.5), lthough produced the gretest yields (158.9 ± 9.6 ushels/cre). There were no significnt differences mong vrieties in stnd counts t 45 dys fter plnting (Figure 2). Stnd counts verged 25, plnts/cre fter three tillge opertions. Any negtive effect from untreted seed ws not evident in this tril. Differences in nutrient levels in er-lef tissue t two months were oserved only for P nd K, where the silge vriety contined significntly greter levels of these nutrients (Figure 3). Stlk nitrte content (Figure 4) ws less thn desired for recommended nitrogen rtes for complete grin fill (7 to 2, ppm), ut grin fill did not seem to e prolem in this tril. Greter yields my e otined with incresed hog mnure ppliction rtes, ut pollution prolems, in the form of nitrogen nd phosphorus leching, could lso result. No corn orer lrve were detected in the 16 plnts smpled on July 1, lthough evidence of feeding ws noted throughout the crop. Dmge levels did not rech the economic threshold (5%) required to justify sprying with Bcillus thuringiensis. Gry lef spot ws lso detected throughout the plnting (Figure 5), ut dmge levels were not s pprent s those oserved in the conventionlly-rised Pioneer 34R6 ( with the Bt gene), plnted on My 14, where 1% of leves indicted significnt level of infection. The gretest mount of infected leves ws oserved in plnts, ut yields were not ffected significntly. There were some differences in grin nlysis (Figure 6) where the silge vriety contined the lest mount of protein nd the gretest mount of strch. Levels were dequte for ll vrieties, however. Results from this tril mimicked results otined y orgnic frmers in Iow where yields of ushels/cres re common. While this corn would e considered trnsitionl (in the three yer trnsition etween conventionl nd orgnic production), the selling price of certified orgnic corn in 1998 verged $3.75/ushel. If corn is sold s orgnic, returns from n verge orgnic corn cre (15 ushels/cre) would e $ Cost of production studies for the Crwfordsville tril (in progress) should compre with those scertined in the Orgnic Corn Tril t the ISU Neely-Kinyon Frm in 1998, where orgnic corn returned 227% profit over conventionl corn (see Armstrong Frm Annul Progress Report, 1999). Acknowledgements We would like to thnk Mtt Hunt, Justin Dvis, nd Milton Miller for their help on production spect of this project. We lso thnk Glen Rippke of the ISU Grin Qulity L for grin nlysis, nd Pioneer Hi-red Interntionl for providing seeds for this study.

4 Figure 1. Yields from orgnic corn tril, Crwfordsville, Figure 2. Corn stnd counts in orgnic tril, Crwfordsville, 1998.

5 c N P K Figure 3. Orgnic corn tril er-lef tissue nlysis, Crwfordsville, Figure 4. Stlk nitrte content in orgnic corn tril, Crwfordsville,

6 c Figure 5. Gry lef spot infection in orgnic corn tril, Crwfordsville, % Protein % Oil Figure 6. Grin nlysis from orgnic corn tril, Crwfordsville, 1998.