A number of different pathogen can be isolated easily f rom healthy and diseased plants and tissues, so that environmental factors determine which species are favored to predominate. Several pathogenic fungi have been associated with stalk rots. These include Diplodia maydis , F. moniliforme , F. graminearum , Colletotrichum graminicola ,and Macrophomina phaseolina among others. Sy mptoms may indicate which pathogen is primarily responsible for attack on individual plant. Return to Outline Important Factors Stalk Rot is favored and progesses optimally under conditions leading to early kernel set coupled with stress later in season.
Environmental stresses are critical in disease development.
The role of plant stresses in development of corn stalk rots. Stalk tissues are thus unable to properly carry out defense measur es against these weak or opportunistic pathogens and are attacked. Support for PSTB theory is found in both circumstantial and experimental evidence. For instance, sugar content is generally found to be higher in the lower stalkof resistant hybrids. In additi on, treatments that increase susceptibility to stalk rot also reduce sugar content in lower stalk .