Root and Stalk Rot in Corn as Affected by Fertilizer and Tillage Treatment¹

Abstract

Synopsis Low nitrogen fertility and the presence of crop residue on the soil surface were coincident with low incidence of rot. Potassium fertilization contributed slightly to decreased disease incidence. All factors that decreased disease incidence were also closely correlated with retarded early growth. Yield was depressed by severe infestation. However, it was impossible to show differential effect of disease on yield as affected by treatment because of interactions of yield, treatment, and disease incidence.

Effects of tillage regimes and herbicides onFusariumspecies associated with corn stalk rot

“…Many researchers have used infection, as measured by isolation in culture, as a measurement of disease incidence (5,14,17,21,30). If the percentage of plants infected in this study were taken as a measure of disease incidence, then tillage regimes did not affect incidence of stalk rot.…”

“…Accordingly, it was decided that samplings could be reduced to early whorl, silk stage (because at this stage, the energy sink switches from vegetative growth to the ears, and the plant is very sensitive to stresses), and harvest (or any period after physiological maturity). Incidence of corn stalk rot has been reported to decrease or remain the same with reduction of tillage (5,7,8,17,21,32). To determine disease incidence, some researchers have used the technique of splitting stalks and rating or measuring internal discoloration (10,20,32).…”

“…To determine disease incidence, some researchers have used the technique of splitting stalks and rating or measuring internal discoloration (10,20,32). Others have attempted to equate softness of stalks when squeezed, lodging, or plant death with disease incidence (7,8,17). These methods present problems because they can be subjective and often are attributable to causes other than stalk rot.…”

“…Simpson (21) reported that the incidence of stalk rot in sweet corn, caused by a complex of organisms, including F, moniliforme, was increased by deep cultivation. Parker and Burrows (17) reported a decrease in root and stalk rot of field corn caused by F. moniliforme and F. graminearum in all tillage systems where crop residues were left on the surface compared with conventional-tillage where residues were plowed under. Yanney (32) reported that notillage and reduced-tillage had equal or lower stalk rot severity and incidence from F. graminearum, Diplodia maydis, and Colletotrichum graminicola than conventional tillage in inoculated or naturally infected field corn.…”

Incidence of Stenocarpella and Fusarium Cob Rots in Monoculture Maize under Different Tillage Systems

“…Tillage practices could, therefore, influence their survival and inoculum production due to effects on stubble placement in or on soil. Indeed, studies indicate that minimum tillage is conducive to S. maydis cob rot and stalk rot and S. macrospora leaf spot (KERR 1965, KRUGER 1970, MORA and MORENO 1984, whereas Eusarium stalk rots either increase in severity or are not affected by ploughing, compared to minimum tillage (PARKER and BURROWS 1959, BYRNES and CARROLL 1986, SKOGLUND and BROWN 1988.…”