Canonical correlation analyses were performed to determine relationships among seed-viability, fungi, and environment in two bulk grain ecosystems. Measurements of 20 variables were made on 8135 samples from two wheat bulks in a farm granary in Winnipeg during 1959–1967. The canonical vectors were interpreted by correlating each set of two canonical variates with the original variates on which they were based. The highest and the second highest significant (P < 0.001) canonical correlation for each combination were field fungi and germination vs. non-biological environment, 0.91 and 0.32; storage fungi vs. non-biological environment, 0.77 and 0.42; field fungi and germination vs. storage fungi, 0.78 and 0.35. In aging grain bulks the attack of the storage fungiChaetomium funicolum, Streptomyces griseus, Aspergillusspp., andRhizopus arrhizusinvolves the loss of grain viability and decrease in the field fungi,Alternaria tenuis, Cochliobolus sativus, andGonatobotrys simplex. Collectively grain temperature and the granary conditions are most important in the reduction of the field fungi; whereas temperature, moisture content, and time are most involved in the infestation ofS. griseus, Penicilliumspp.,C. funicolum, Aspergillusspp., andR. arrhizus.