Influence of the cropping pattern on aflatoxin contamination in preharvest Kharif (monsoon) maize crop (Zea mays)

Aflatoxin contamination in three varieties of maize (Zea mays L), viz Diara composite, M₉ and Suwan composite, under various cultivation rates and planting densities was examined during the 1987 and 1989 Kharif (monsoon) crops. Cultivation rates comprising single line weeding (SLW) with one spading, SLW with two spadings and SLW with three spadings did not have significant effects on aflatoxin production in the preharvest standing crop. Of the three planting populations, the toxin level was highest under 56000 plants ha^?1 followed by 83000 plants ha^?1, and 67000 plants ha^?1 in Aspergillus flavus inoculated plots (I₁) and uninoculated plots (I₀), respectively. The variety M₉ was most susceptible to A flavus infection and supported higher aflatoxin production under I₁ condition. Aflatoxin concentration was lowest in Diara composite. Correlation analysis showed a positive and highly significant relation between A flavus incidence and aflatoxin contamination (r = +0.73, P < 0.01).