Oxygen depleted controlled or modified atmospheres (CA/MA) generated by a variety of different methods and alteration of temperature of stored cereals have been used successfully to replace fumigants for insect control and for the quality preservation of stored products. CA or MA have been used in specially constructed rigid structures for the preservation of cereal grains. Plastic structures suitable for long-term, large-scale storage or for intermediate storage of grain in bags or in bulk have been developed and applied. Although high temperatures are detrimental to insects, their use in cereal preservation remains very limited because of the disadvantages of heating the treated cereals. On the other hand, aeration is a widely used method to modify the grain bulk microclimate to render it unfavorable for the development of damaging organisms in the grain. Low kernel temperatures are desirable for better maintenance of seed and grain quality. Equalization of temperature through-out the grain bulk prevents moisture migration. Spontaneous heating of moist grain can be prevented by cooling the grain mass. Chilled aeration with refrigerated air can be used when ambient air may not be sufficient to cool grain in warm climates.