Submitted to: National American Phytopathology Meetings
Publication Type: Abstract only
Publication Acceptance Date: 5/18/2006
Publication Date: 6/15/2006
Citation: Abbas, H.K., Shier, W.T., Johnson, B.J., Cartwright, R.D., Dong, Y. Effect of planting date on aflatoxin and fumonisin contamination in commercial corn hybrids in arkansas. National American Phytopathology Meetings, 96:S2. Interpretive Summary:
Technical Abstract: Corn (Zea mays L.) is an important crop in the southeastern USA, where it is used for animal feed, alcohol fermentation and direct human consumption. Corn, especially in warm climates, is susceptible to infection by a variety of toxigenic fungi, most importantly Aspergillus flavus and Fusarium species. Corn planting dates vary by region, and improved technology has allowed earlier planting. To evaluate the effect of planting date on mycotoxin levels in corn, 9 commercial hybrids (including Bt and non-Bt corn) were planted in Arkansas at two dates (April and May) in each of 2002, 2004 and 2005 and became naturally infected with Aspergillus spp. and Fusarium spp. Corn kernel samples collected at harvest were assayed by ELISA for total aflatoxins and fumonisins. In 2002, corn samples from all hybrids planted in April contained less than or equal to 12.2 ppb aflatoxin, while only one hybrid out of 9 planted in May yielded corn with aflatoxin >20 ppb (224 ppb). Fumonisin levels in the same 2002 samples were higher in corn planted in May (4.7 to 38 ppm), than in April (0.5 to 6 ppm). Of the 9 hybrids, only one (DK 687) had more fumonisin in the April planting. In 2004 and 2005, corn samples from all hybrids planted in April contained less than or equal to 20 ppb aflatoxin, while 7 hybrids out of 18 planted in May yielded corn with aflatoxin >20 ppb (26.6-184.3 ppb). Fumonisin levels in the same 2004 and 2005 samples ranged from 1.9 to 21.9 ppm and were not significantly different for April and May planting dates. The study observed frequent co-occurrence of both toxins in corn samples; planting dates did not significantly affect mycotoxin contamination. Mycotoxin levels in Bt-hybrids were not significantly lower than in non-Bt hybrids.