Liu Jun, Zhao Qidi, Huang Haiyan, Ye Rongjian, Stewart Charles Neal, Wang Junming
School of Information Science and Engineering, Chongqing Jiaotong University, Chongqing 400074, China.
Illinois State Water Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA.
Plants (Basel). 2022 Apr 19;11(9):1102. doi: 10.3390/plants11091102.
The wide dispersion of glyphosate-resistant (GR) horseweed ( (L.) L.) biotypes has been reported in agricultural fields in many states. GR traits may be transferred through seeds or pollen from fields with existing GR horseweed prevalence to surrounding fields. Understanding seed production and movement is essential when characterizing and predicting the spread of GR horseweed, yet a literature review indicates that there are no experimental data on dynamic (hourly) seed production and horizontal dispersion and deposition from horseweed. To obtain the dynamic data, two field experiments were performed, one in Illinois and one in Tennessee, USA in 2013 and 2014, respectively. Seed concentration and deposition along with atmospheric conditions were measured with samplers in the Illinois (184 m × 46 m, natural plants, density = 9.5 plants/m) and Tennessee (6 m × 6 m, cultivated plants, density = 4 plants/m) experimental fields and their surrounding areas along the downwind direction up to 1 km horizontally and 100 m vertically in the Illinois field and up to 32 m horizontally and 5 m vertically in the Tennessee field. The dynamic seed source strengths (emission rates) measured during two entire seed-shedding seasons were reported, ranging from 0 to 0.41 grains/plant/s for Illinois and ranging from 0 to 0.56 grains/plant/s for Tennessee. The average total seed production was an estimated 122,178 grains/plant for the duration of the Illinois experiment and 94,146 grains/plant for Tennessee. Seeds trapped by Rotorod samplers attached beneath two balloons in the Illinois field experiment were observed at heights of 80 to 100 m, indicating the possibility of long-distance transport. Normalized (by source data) seed deposition with distance followed a negative power exponential function. Seed emission and transport were affected mainly by wind speed. This study is the first to investigate dynamic horseweed seed emission, dispersion, and deposition for an entire seed-shedding season. The results will aid in the management of GR horseweed. The potential for regional effects of horseweed invasion may require all farmers to control horseweed in their individual fields.
许多州的农田中都报告了抗草甘膦（GR）的加拿大飞蓬（(L.) L.）生物型广泛分布的情况。GR性状可能通过种子或花粉从已有GR加拿大飞蓬的田地传播到周边田地。在描述和预测GR加拿大飞蓬的扩散时，了解种子生产和移动情况至关重要，但文献综述表明，目前尚无关于加拿大飞蓬动态（每小时）种子生产以及水平扩散和沉降的实验数据。为了获取动态数据，分别于2013年和2014年在美国伊利诺伊州和田纳西州进行了两项田间试验。在伊利诺伊州（184米×46米，天然植株，密度 = 9.5株/平方米）和田纳西州（6米×6米，栽培植株，密度 = 4株/平方米）的试验田及其周边区域，沿着顺风方向水平至1公里、伊利诺伊州试验田垂直至100米以及田纳西州试验田水平至32米、垂直至5米的范围内，使用采样器测量种子浓度、沉降以及大气条件。报告了在两个完整的种子脱落季节测量到的动态种子源强度（排放率），伊利诺伊州为0至0.41粒/株/秒，田纳西州为0至0.56粒/株/秒。伊利诺伊州试验期间的平均总种子产量估计为每株122,178粒，田纳西州为每株94,146粒。在伊利诺伊州田间试验中，附着在两个气球下方的旋转棒采样器捕获的种子出现在80至100米的高度，表明存在远距离传播的可能性。归一化（按源数据）后的种子沉降随距离呈负幂指数函数变化。种子排放和传输主要受风速影响。本研究首次对整个种子脱落季节加拿大飞蓬种子的动态排放、扩散和沉降进行了调查。研究结果将有助于GR加拿大飞蓬的管理。加拿大飞蓬入侵的区域影响潜力可能要求所有农民在各自的田地里控制加拿大飞蓬。
