Martin Daniel E, Latheef Mohamed A
USDA-ARS, SPARC-AATRU;
USDA-ARS, SPARC-AATRU.
J Vis Exp. 2017 Apr 28(122):54314. doi: 10.3791/54314.
The objective of this study was to evaluate a ground-based multispectral optical sensor as a remote sensing tool to assess foliar damage caused by the two-spotted spider mite (TSSM), Tetranychus urticae Koch, on greenhouse grown cotton. TSSM is a polyphagous pest which occurs on a variety of field and horticultural crops. It often becomes an early season pest of cotton in damaging proportions as opposed to being a late season innocuous pest in the mid-southern United States. Evaluation of acaricides is important for maintaining the efficacy of and preventing resistance to the currently available arsenal of chemicals and newly developed control agents. Enumeration of spider mites for efficacy evaluations is laborious and time consuming. Therefore, subjective visual damage rating is commonly used to assess density of spider mites. The NDVI (Normalized Difference Vegetation Index) is the most widely used statistic to describe the spectral reflectance characteristics of vegetation canopy to assess plant stress and health consequent to spider mite infestations. Results demonstrated that a multispectral optical sensor is an effective tool in distinguishing varying levels of infestation caused by T. urticae on early season cotton. This remote sensing technique may be used in lieu of a visual rating to evaluate insecticide treatments.
本研究的目的是评估一种地面多光谱光学传感器，作为一种遥感工具，用于评估温室种植棉花上由二斑叶螨（TSSM），即棉叶螨（Tetranychus urticae Koch）造成的叶片损害。二斑叶螨是一种多食性害虫，出现在各种大田和园艺作物上。在美国中南部地区，它常常在棉花生长早期就以具有破坏性的比例成为害虫，而不是像后期那样成为无害害虫。评估杀螨剂对于维持现有化学药剂和新开发防治剂的效力以及防止产生抗药性很重要。为进行效力评估而对叶螨进行计数既费力又耗时。因此，通常使用主观的视觉损害评级来评估叶螨密度。归一化植被指数（NDVI）是描述植被冠层光谱反射特性以评估因叶螨侵扰导致的植物胁迫和健康状况时使用最广泛的统计量。结果表明，多光谱光学传感器是区分棉叶螨对早期棉花造成的不同侵扰水平的有效工具。这种遥感技术可用于替代视觉评级来评估杀虫剂处理效果。
