STORING SHELLED CORN in ALABAMA J. L. BUTT, Associate Agricultural Engineer H-. S. WARD, Associate Botanist W. G. EDEN, Entomologist S l I It'of (01 i i ii i s beoi ii i i T tIll popla ti tlllllit fliti I liltitt orCiii i tits xlit k c 2i of lud1d ii i crailI Ole ii l d tffitill fo tw lx XXiti Ii tt p uli i lv it I (It fiicI it k \ it h mli i teii c til l l4 cioi cot it( itt lis itllcrto l ici i sliii 10 col ii for st li it li e(lct \( tlr Ohi ld ar c1 o>1tniiind ist ityc a (5) siicdii Th lit' xtii,i( pt i-o \\lXXl it",X Wl iti Itt ~ ~ 192 Ititl ixil IXliitthit itl Va- ii h i i l i lii t illotx ille lii ijt ilt gii ti it 13.2t lii i iit t I lts. S iil xiPIilt d ii\ XX ti t 10l t i l i it iiic it i tti at t ilt o te)ii s iwc i iii dii slw4C XX O Its ptl teli o11lit tiliil iiiilut Xtill lliiXX X (1. oiclt i1114 xii1t . h l~ dlil( stIIX _t 1411 X I 173. illitixl (I it t x v e oa t orag b11 illii atr Deeit iherll 1, . 51 ti(utI22 1 952.itl uTh 122 ti istl iiiiijtit (111 Xthei litti 'Iiiliii iit. Ilii tosill \i(I l X ( li lt. AGRICU LTU RAL EXPERIMENT 4 M ALABAMA POLYTECHNIC F= V. Smith. Diiecio, S T ATIO N I N ST IT UTE Auiburn, Alabama JANUARY 1954LEAFLET No. 41 ly infested with insects at storage time and was fumigated immediately. On June 22 the moisture content tested 11.8 per cent and the corn had lost 60 pounds in weight. Germination tested the same before and after storage. In none of these tests did germina- tion, weight, or grade change sufficient- ly to indicate a lowering of quality dur- ing the storage period. Therefore, it was concluded that shelled corn can be stored safely on the farm under Ala- bama conditions if certain requirements are met. REQUIREMENTS /0 SAFE STORAGE 4q SHELLED CORN Storage structure. A grain storage bin must be weather-tight, rodent re- sistant, tight enough to fumigate, and strong enough to support the weight and side-pressure of stored grain. For example, it is reported that in grain stored 10 feet deep in a 12-foot diame- ter bin, the force of the grain pushing sideward against one square foot along the bottom of the wall can amount to 230 pounds.' A total side pressure of about 1,300 pounds would push against a one-foot strip of wall from top to bot- tom. Therefore, care must be taken to have wall studs sound, large enough, spaced close enough together, and se- curely fastened at top and bottom. Me- tal bins made by reputable companies are designed to withstand these press- ures. The structure should be made rat- resistant in accordance with best pro- cedures for the particular kind of bin. The bin should have convenient empty- ing and filling doors that can be made tight. Facilities for frequent sampling to check on quality should be provided. A well-drained, accessible site is neces- sary. A convenient arrangement of bins to permit shifting from one to another or to processing facilities is desirable. 1 Stahl, Benton M. "Grain Bin Require- ments" USDA Circular No. 835, 1950. A view showing features to keep in mind while constructing a storage bin. Handling and inspection. Light, low-cost portable elevators are available for handling shelled corn and other grain crops. These units will fill a 1,000- bushel bin in less than an hour. The savings in labor will soon pay for a unit if much grain is handled. The elevator should not crack the grain. A flexible discharge spout is desirable to avoid accumulations of trash. Trash and cracked or damaged grain are conducive to moisture, heating and insect damage. If scattered evenly throughout the stored grain, trash and cracked grain are less likely to cause trouble. If the percentage of this ma- terial is high, however, the corn should be cleaned before it is placed in storage. It is extremely important to check stored corn frequently for possible ac- cumulations of moisture and for insect and rodent signs. Moisture accumula- tions can result from leaky roofs, tem- perature changes in the stored grain, or other causes and may go unnoticed un- less frequent and thorough observations are made. These observations must cover the entire lot of grain, as small damaged spots are easily overlooked. Grain probes simplify the inspection procedure. Moisture content. The moisture content of stored corn probably is the most important single factor affecting storage. Shelled corn having too much moisture in storage will heat, become moldy, provide an ideal condition for insects, and as a result, become poorer in quality. At low moisture contents these related factors are reduced. For example, studies in other states have shown that corn stored for 2 years at 9.7 per cent moisture germinated 91.8 per cent, when stored at 11.0 per cent moisture germination was 85.2 per cent, at 12.0 per cent moisture it was 65.5 per cent, and at 14.0 per cent moisture germination was 0 per cent. The longer corn is in storage the greater is the loss in quality. For in- stance, corn stored at 12 per cent mois- ture germinated 88.8 per cent after 1 year of storage but dropped to 65.5 per cent germination after storage for 2 years. 2 Storage at high temperatures causes corn to decrease in quality. Corn con- taining 14.6 per cent moisture was held for 2 years at 28' Fahrenheit and germ- inated 82 per cent. Corn at the same moisture stored for 2 years at 72' F. germinated 0 per cent. 3 High tempera- tures prevail in Alabama, yet by lower- ing the moisture content sufficiently, corn can be stored safely. Considering local climatic onditions, 12 per cent moisture is recommended as a maximum for safe storage of shelled corn for one year or less. Corn for grain can undergo some drop in germination without the other grain quality factors being affected. However, the fact that germination de- creases serves as warning that other quality factors might be affected. Natural vs. artificial drying. Corn will usually dry to a safe storage mois- ture content if left in the field long enough This procedure, however, is entirely dependent upon the weather. For machine picking, it is desirable to harvest before the stalks begin to lodge. Early harvesting also reduces field losses from insects, birds, stray live- stock, and weather. However, corn har- vested early is likely to contain too much moisture for safe storage. When this is true, it will be necessary to arti- ficially dry the corn to the safe storage moisture content. General information concerning fans, motors, and supplemental heat is given in A.P.I. Agricultural Experiment Sta- tation Leaflet No. 88, "Aids to Planning -Semeniuk, G., Nagel, C. M., and Gil- man, J. C. "Observations on Mold Devel- opment and on Deterioration in Stored Yellow Dent Shelled Corn." Iowa Agri- cultural Experiment Statidn Research Bul- letin 340, 1947. ' Sayre, J. D. "Storage Tests with Seed Corn" Farm and Home Research 82: 149- 154. 1947. an Artificial Curing System for Hay." For shelled corn drying, a blower cap- able of delivering a minimum of 4 CFM (cubic feet per minute) of air per cubic foot of grain (or 5 CFM per bushel of grain) is recommended.. More air will give faster drying. Further, the fan or blower must deliver this volume of air even though the grain offers resistance to air flow. To overcome this resistance the blower should deliver the recom- mended air flow against 1" SP (static pressure) for corn stored 4 feet deep or against 2" SP if stored 6 feet deep. If supplemental heat is used, a maxi- mum temperature of 110o F. is recom- mended for drying seed corn. Fuel and electricity costs for drying range from 1 to 5 cents per bushel depending upon moisture contents, weather conditions, and efficiency of the drier. Someone familiar with the design and operation of driers should be consulted before se- lecting equipment or planning a drying bin. Protection against insects. The principal insect pests of shelled corn in storage in Alabama are the rice weevil, the Indian and the Angoumois grain moths, the cadelle, and the yellow meal worm. These pests can be economically controlled if proper control measures are followed. Bins should be thoroughly cleaned before corn is placed in them. After cleaning, the entire inner surface should be sprayed with a DDT solution using 2 pounds of 50 per cent wettable DDT powder to 5 gallons of water or 1/2 gal- lon of 25 per cent emulsifiable concen- trate to 4 gallons of water. To give thorough coverage will require about 2 gallons per 1,000 square feet of sur- face area. Fumigation is an economical and ef- fective method of controlling insects in stored grain. For fumigation to be ef- fective a bin must be made practically air tight by sealing doors and other openings with masking tape. The following fumigants are recom- mended at the specified rates: 1. Ethylene dichloride-carbon tetra- chloride, 3 to 1 mixture, applied at the rate of 5 gallons per 1,000 cubic feet in steel bins or 61/4 gallons in wooden bins. 2. Carbon tetrachloride and carbon disulphide, 4 to 1 mixture; applied at the rate of 5 gallons per 1,000 cubic feet in steel bins or 61/4 gallons in wooden bins. 3. Methyl bromide, applied at the rate of 1 pound per 1,000 cubic feet. Methyl bromide fumes are highly toxic to warm-blooded animals as well as in- sects. Extreme care should be exer- cised to prevent exposure to it. CAUTION: The gasses given off by all fumigants are toxic to man and ani- mals. Although some are more hazard- ous than others, caution should be used to prevent exposure to any fumigants. Protectant dusts containing 0.05 per cent pyrethrins and 0.8 per cent piper- onyl butoxide are effective for several months in preventing insect damage in uninfested or very lightly infested shelled or shucked ear corn. The dust should be applied at the rate of 1 pound to 10 bushels of corn and thor- oughly mixed with the grain. The top 3-inch layer of grain in a bin should be "capped" with 2 or 3 times the above rate of dust. For complete information, see A. P. I. Agricultural Experiment Station Leaflet No. 40, "Control of Insects in Stored Grain." CONCLUSION Clean, shelled corn of good quality containing 12 per cent moisture or less can be stored on the farm for as long as one year without loss in quality if placed in adequate storage structures and protected from insects.