Effect of genotype (open‐pollinated vs hybrid) and environment on preharvest aflatoxin contamination of maize grown in southeastern united states

Abstract

Currently popular maize hybrids were compared with open‐pollinated varieties grown in die Southeast prior to 1940 for susceptibility to preharvest aflatoxin contamination. Parallel planting were made of 4 hybrids and 8 varieties at 8 locations, most located in the Southeast, in both 1979 and 1980. The test ears, dried immediately after picking, were examined for insect damage (1980 only) and the ground, shelled kernels analyzed for aflatoxins. Aflatoxin incidence and levels were positively related to location and crop year, but not to genotype, except for one variety that was significantly more susceptible to aflatoxin contamination than the others. There was no correlation of aflatoxin occurrence with either drought stress or maximal temperature during the period between flowering and harvest, but insect damage did correlate to some extent with the severity of contamination in 1980 both in relation to genotype and to location, except for the one location (Florence, SC) at which the most severe contamination was encountered. The severity of contamination at this location could not be explained by any of the known or hypothetical factors that have been developed.

Controlling Aflatoxin and Fumonisin in Maize by Crop Management

“…It was also observed that a greater contrast in these differences occurred during a year of lower than normal rainfall. However, Stoloff and Lillehoj (1984) observed higher concentrations of aflatoxin in maize produced in 1980 than in 1979 despite the application of irrigation. They concluded that preconditioning maize for production of aflatoxin probably involves several factors that work independently or interactively to alter aflatoxin levels in the grain at harvest.…”

“…Visible deficiency symptoms represent the most severe form of negative expression in plant metabolism and development. A phosphorus (P) deficiency in maize during the early weeks of growth can result in a poorly developed root system, which in turn can reduce the plant's ability to take up adequate levels of other essential nutrients and water (Stoloff and Lillehoj, 1984). This could logically lead to the early onset of drought stress, which has already been discussed as a prerequisite to fungal infection and mycotoxin development.…”

Crop Stress and Aflatoxin Contamination: Perspectives and Prevention Strategies

“…The concept was corroborated by several fi eld studies in which temperatures were monitored (Jones et al 1980 ;Zuber et al 1983 ) . Some efforts to illustrate a relationship between temperature and afl atoxin contamination were, however, unsuccessful (Stoloff and Lillehoj 1981 ) . The reason for this phenomenon can be traced to a detectable relationship that exists only during years when afl atoxin contamination is high.…”

Aflatoxins Biochemistry and Molecular Biology - Biotechnological Approaches for Control in Crops

“…The establishment of temperature as an important component of infection by A. flavus and subsequent aflatoxin contamination has been clearly demonstrated under controlled greenhouse conditions (Payne et al, 1988). Some efforts to illustrate a relationship between temperature and aflatoxin contamination were unsuccesfull (Stoloff and Lillehoj, 1981). The reason for this phenomenon can be traced to the finding that a detectable relationship exists only during years when amounts of contamination are high (McMillian et al, 1985).…”