AFLATOXIN IS REDUCED IN CORN

Afla-Guard and AF 36 were evaluated for the control of aflatoxin in corn at the Mayo Farm, just south of Robstown on CR 77, in a replicated, randomized experiment by Tom Isakeit, Professor & Extension Plant Pathologist and myself.  Rainfall was below normal during the growing season, providing sub-optimal conditions for performance of these control agents.  Afla-Guard treatment, applied at V10,  resulted in significantly less aflatoxin (2 ppb) than the control (31ppb).  AF 36 treatments, applied either at “knee-high” (V4-V5) or at V10, had 27 ppb and 30 ppb, respectively.  These averages were not significantly different from the control. 

Treatment / Date / Growth Stage	Aflatoxin (PPB)*	% Colonization of kernels  by A. flavus*
AF 36 on 3/30/11 (V4-V5)	27 a	7 a
AF 36 on 4/20/11 (V10)	30 a	10 a
Afla-Guard on  4/20/11 (V10)	2 b	7 a
Control- No Treatment	31 a	2 b

*Mean of four replicates. Log-transformed data was analyzed.  Numbers within a column followed by different letters are significantly (P=0.05) different using an analysis of variance.

There were significantly higher levels of colonization of  harvested, non-symptomatic corn kernels by A. flavus with atoxigenic strain treatments, as compared with the control in  above Table.  Atoxigenic strains of A. flavus work by colonizing kernels, but without causing disease symptoms.  Their presence physically excludes subsequent colonization by toxin-producing strains.  This experiment showed a significant reduction in aflatoxin in corn following treatment with Afla-Guard at V10.  Based on experiments conducted in other counties, even though AF 36 had no effect at this location, it is premature to suggest that there is a difference in performance between AF36 and Afla-Guard.