Abstract
Preharvest aflatoxin contamination (PAC) of peanut occurs under prolonged periods of drought and heat stress. Evaluation of peanut germplasm may identify valuable sources of resistance to PAC, but will require a large scale screening system. The objective of this research was to develop a large-scale field system for screening peanut germplasm for resistance to PAC at Yuma, Arizona. Yuma is located in a desert and has great potential as a site for evaluating germplasm for resistance to PAC. Field studies were conducted in 1990 to determine if aflatoxin contamination would occur in drought stressed peanuts grown at Yuma. Aflatoxin levels up to 2,260 ppb were observed, however, 52% of the plots escaped contamination and the coefficient of variation (C.V.) were unacceptably large. During testing at Yuma in 1990 it was noted that drought stressed plants died quickly due to the rapid exhaustion of soil moisture. A subsurface irrigation system was installed in 1991 to alleviate this problem and allow for an extended period of drought stress in the pod zone. Results for 1991 showed a greatly increased mean aflatoxin contamination, a 50% reduction in the C.V., and a virtual elimination in the occurrence of escapes. A study was conducted in 1992 to compare plots with and without subsurface irrigation to determine if the differences observed between 1990 and 1991 were due to the use of subsurface irrigation. The use of subsurface irrigation in 1992 increased the mean contamination by over 100%, reduced the C.V. by over 50%, and reduced the percentage of escapes by over 90%.
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Keywords: aflatoxin, Arachis hypogaea, Aspergillus flavus, Aspergillus parasiticus, germplasm evaluation, peanut
How to Cite:
Holbrook, C. & Matheron, M. & Wilson, D. & Anderson, W. & Will, M. & Norden, A., (1994) “Development of a Large-Scale Field System for Screening Peanut for Resistance to Preharvest Aflatoxin Contamination¹”, Peanut Science 21(1), p.20-22. doi: https://doi.org/10.3146/i0095-3679-21-1-6