The effect of aqueous leaf extracts of four plants, Argemone mexicana, Cyperus rotundus, Euphorbia hirta and Solanum nigrum, on growth and aflatoxin production by Aspergillus flavus was studied in SMKY liquid medium. All the plants inhibited aflatoxin production. No correlation between the growth of the fungus and aflatoxin synthesis was observed. The influence of these plants on the ratio of aflatoxin B1 to G1 is discussed.

ABSTRACT

The influence of six fungitoxicants on growth and aflatoxin production by Aspergillus flavus was tested in liquid SMKY medium at two concentrations, viz. 0.1 and 0.5%. Thiram completely inhibited the aflatoxin production at 0.5% concentration. Other fungitoxicants showing more than 60% inhibition were bavistin and daconil. Vitavax (0.1%) and agrosan GN (0.1 and 0.5%) stimulated the growth of fungus and aflatoxin elaboration after 7 d of incubation. Dithane M‐45 moderately inhibited aflatoxin synthesis. Treatment with fungitoxicants also alters the ratio of B1 and G1.

No abstract

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).