Submitted to: Aflatoxin Workshop
Publication Type: Abstract Only
Publication Acceptance Date: 11/5/2007
Publication Date: 12/15/2007
Citation: Nuti, R.C., Dorner, J.W., Sorensen, R.B., Lamb, M.C., Truman, C.C. 2007. Water Conservation and Preharvest Aflatoxin Contamination in Peanut and Corn. Aflatoxin Workshop. Interpretive Summary: None required.
Technical Abstract: Water remains a major limiting resource in consistent crop production in the Southeast US. Avoiding drought stress is the main factor for preventing preharvest aflatoxin contamination in peanut and corn. Furrow diking is a tillage operation that creates a series of basins and dams in the furrow to catch water delivered by either rainfall or irrigation. Improving water capture for field crops in the Southeast would improve irrigation efficiency while reducing input costs and has the potential to affect preharvest aflatoxin contamination by improving soil moisture. A series of field experiments was conducted in 2005-2007 near Dawson, Georgia using furrow dikes in irrigated and non-irrigated peanut and corn. The objectives included monitoring soil moisture levels to determine if water can be saved in irrigated systems with furrow dikes compared to those in conventionally tilled systems. Irrigator Pro, a decision based computer software program, was used for irrigation recommendations. In non-irrigated experiments, soil moisture and yield parameters were monitored to document impact of furrow dikes within those systems. Large samples were processed to quantify the presence of aflatoxin at harvest in peanut and corn. The 2005 growing season had abundant rainfall. Peanut and cotton crops only required one irrigation. Furrow diked corn was irrigated 3 times and non-diked corn required 5 irrigations. Despite abundant rainfall, higher levels of soil moisture were maintained in plots with furrow dikes compared to conventional plots. Similar yields were attained in all crops regardless of furrow diking in 2005. Levels of aflatoxin in corn ranged from 7 to 191 ppb and none was found in peanuts in 2005. The 2006 and 2007 seasons required more frequent irrigation because of drought conditions. Aflatoxin in corn was significantly impacted by irrigation in these 2 drought years, but furrow diking did not reduce preharvest aflatoxin contamination. Non-irrigated corn yield was improved 17% by furrow diking in 2007. No aflatoxin was found in peanuts grown in 2006, while yield of like treatments were similar. At the time of this meeting, the 2007 peanuts had not been harvested. Trends for aflatoxin prevention in corn are evident in these studies. Strong results for soil and water conservation, yield improvement, and economic feasibility for furrow diking have been shown in associated studies. Furrow diking improves the efficiency of water capture, however, there must be water in the system to take advantage of. Further investigation is necessary to either strengthen/disprove the reliability of furrow diking tillage to affect preharvest aflatoxin contamination of crops in the Southeast US.