- Sweet corn is susceptible to various pathogenic Fusarium species and has been long known to be subject to early season diseases of seed rot and seedling blight as well as root rot and later season problems with stalk rot and ear rots. More recently, fields in the Willamette Valley of Oregon as well as other areas have had outbreaks of plants exhibiting leaf-firing, in which the leaves die prematurely starting at the base of the plant and then progressing upwards, and a crown and stalk node rot. Recent investigations have shown that crown rot, accompanied by a stalk node rot, appears to explain much of the observed leaf firing and the concomitant loss in yield, rather than root rot and that adventitious roots may be diseased as the pathogen(s) move from the crown outward and upward.
Other factors contribute to sweet corn yield declines when Fusarium species are involved, especially in crown and stalk node rot, including characteristics of specific cultivars or hybrids, environmental conditions which stress plants or favor Fusarium (high temperatures seem to promote Fusarium crown and stalk node rot as well as soil compaction, dry soil conditions, high manure rates, etc.), and the microbial population associated with seeds or soil.