Columbia Basin Agricultural Research Center, Oregon State University, Adams, OR 97810, USA.
Soil and Water Conservation Research Unit, Agricultural Research Service (USDA-ARS), Adams, OR 97810, USA.
Sensors (Basel). 2017 Oct 19;17(10):2381. doi: 10.3390/s17102381.
Kochia ( L.), Russian thistle ( L.), and prickly lettuce ( L.) are economically important weeds infesting dryland wheat ( L.) production systems in the western United States. Those weeds produce most of their seeds post-harvest. The objectives of this study were to determine the ability of an optical sensor, installed for on-the-go measurement of grain protein concentration, to detect the presence of green plant matter in flowing grain and assess the potential usefulness of this information for mapping weeds at harvest. Spectra of the grain stream were recorded continuously at a rate of 0.33 Hz during harvest of two spring wheat fields of 1.9 and 5.4 ha. All readings were georeferenced using a Global Positioning System (GPS) receiver with 1 m positional accuracy. Chlorophyll of green plant matter was detectable in the red (638-710 nm) waveband. Maps of the chlorophyll signal from both fields showed an overall agreement of 78.1% with reference maps, one constructed prior to harvest and the other at harvest time, both based on visual evaluations of the three green weed species conducted by experts. Information on weed distributions at harvest may be useful for controlling post-harvest using variable rate technology for herbicide applications.
藜（L.）、俄罗斯蓟（L.）和刺莴苣（L.）是美国西部旱地小麦（L.）生产系统中具有重要经济意义的杂草。这些杂草在收获后产生大部分种子。本研究的目的是确定安装用于即时测量谷物蛋白质浓度的光学传感器检测流动谷物中绿色植物物质存在的能力，并评估该信息在收获时绘制杂草图的潜在有用性。在收获两个春小麦田（1.9 和 5.4 公顷）期间，以 0.33 Hz 的速率连续记录粮流的光谱。使用具有 1 m 定位精度的全球定位系统（GPS）接收器对所有读数进行地理参考。绿色植物物质的叶绿素在红色（638-710nm）波段中是可检测的。来自两个田地的叶绿素信号图与参考图的总体一致性为 78.1%，其中一个参考图是在收获前构建的，另一个是在收获时基于专家对三种绿色杂草物种进行的视觉评估构建的。收获时杂草分布的信息可能有助于通过变量率技术控制收获后使用除草剂。
