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Field Studies on Dynamic Pollen Production, Deposition, and Dispersion of Glyphosate-Resistant Horseweed (Conyza canadensis)

  • Rongjian Ye (a1), Haiyan Huang (a2), John Alexander (a1), Wusheng Liu (a1), Reginald J. Millwood (a1), Junming Wang (a2) and C. Neal Stewart (a1)...


Glyphosate-resistant (GR) horseweed has become an especially problematic weed in different crop production systems across the United States and the world. In this field study, we used a nondestructive measurement system to analyze the pollen production, deposition, and dispersion of a Tennessee glyphosate resistant (TNR) horseweed biotype in Knoxville, TN during the 2013 pollination season. We observed that the pollination season of TNR horseweed lasted about 2 mo (54 d). About 78.93% of horseweed pollen was released between 9:00 A.M. and 7:00 P.M. during each sampling day and the release peak was at about 1:30 P.M. The seasonal release of pollen grains was estimated to be 5.11 million grains plant−1. The release rate data indicated that the integrated horizontal flux density and deposition flux density contributed to 78.17% and 21.83% of the release rate, respectively. We also found that pollen concentration decreased with distance from the source field; the average pollen concentration decreased to 50.69% at a distance of 16 m from the source plot. This is the first result of a systematic, direct examination of the release rate (emission and deposition), release pattern (daily and seasonal), and dispersion pattern of GR horseweed pollen.


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Associate Editor for this paper: Vijay Nandula, Mississippi State University.



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Field Studies on Dynamic Pollen Production, Deposition, and Dispersion of Glyphosate-Resistant Horseweed (Conyza canadensis)

  • Rongjian Ye (a1), Haiyan Huang (a2), John Alexander (a1), Wusheng Liu (a1), Reginald J. Millwood (a1), Junming Wang (a2) and C. Neal Stewart (a1)...


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