Submitted to: Crop Management at www.cropmanagement.org
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 3, 2009
Publication Date: October 16, 2009
Citation: Bruns, H.A., Abbas, H.K. 2009. Clipping corn plants at the 3 and 5 leaf growth stage fails to simulate uneven emergence. Crop Management. doi:10.1094/CM-2009-1016-01-RS. Interpretive Summary: Uneven emergence of corn seedlings has previously been shown to reduce yields. Such stress might also contribute to increased levels of aflatoxin. Clipping young corn plants in research reported 10 or more years ago, showed delayed maturity and reduced yields. Corn plants were clipped at the 3-leaf and 5-leaf growth stage in an experiment at Stoneville, MS in 2005 to 2007 to try to simulate uneven emergence of plants in the row. Clipping had no impact on yield, kernel weight, test-weight or aflatoxin contamination. Clipping as a means of delaying maturity and stressing the plants, did not appear to increase aflatoxin contamination with the more modern hybrids.
Technical Abstract: Corn (Zea mays L.) planted in dry clay soils in the Mississippi Delta may not receive sufficient moisture to readily germinate or complete germination resulting in irregular stands or substantial intra-row skips. Previous research has shown irregular stands can reduce yields. Plants stressed by uneven competition found in irregular stands have the potential of being infected by mycotoxin forming fungi. This research conducted from 2004-2006, attempted to simulate uneven emergence in corn by imposing 12 different clipping patterns at growth stages V3 and V5. The experimental design used was a 3 X 4 rectangular lattice. Significant differences in yield, kernels ear-1, kernel weights, aflatoxin contamination, and fumonisin contamination among clipping treatments were observed but with no consistency between years. Compared to previous research on uneven emergence in corn, clipping did not simulate similar effects. The lack of these effects may be due in part to modern corn hybrids being more stress tolerant.