Pecan (Carya illinoinensis) is an important specialty crop in the U.S.A., but yield is limited by several diseases and pests. In mature-tree pecan orchards, large air-blast sprayers are commonly used to apply the pesticides to control these diseases and pests. The spray coverage, deposition and profiles are poorly defined under the range of application scenarios, limiting the recommendations that can be provided to growers to maximize control while minimizing input costs. To explore effects of sprayer setting parameters such as travel speed and spray volume rate on spray coverage on tall targets we set up a system (a simple vertical patternator) using a 19-m-tall pole with cards attached at eight height levels from 5 to 19 m above ground, allowing to determine the vertical distribution pattern of two air-blast sprayers with different air discharge systems. Spray was applied with a standard radial-flow air-blast sprayer during six treatments being combinations of two travel speeds: 2.4 and 3.2 km/h, and three spray volume rates: 470, 940 and 1970 L/ha, as well as with a focused air-flow system (a volute) sprayer during four treatments being combinations of two travel speeds: 2.4 and 3.2 km/h, and two spray volume rates: 470 and 940 L/ha. Results show that using a standard radial air-flow sprayer, application volume affected coverage at heights ≤17 m (higher volumes resulting in more coverage). Higher speed using a standard radial air-flow sprayer resulted in greater spray coverage, but was inconsistent with the focused air-flow system. Using a focused air-flow system more spray coverage occurred at >17 m compared to a standard radial air-flow sprayer. Spray coverage profiles affirmed the rapid decline in coverage with height using a standard radial air-flow sprayer. The results may help guide decisions on volute use, spray volume, and spray partitioning to different parts of the canopy to improve spray profile characteristics for applying more uniform spray coverage to mature pecan tree canopies.

山核桃（Carya illinoinensis) 是美国重要的特种作物，但产量受到多种病虫害的限制。在成熟的山核桃园中，通常使用大型气流喷雾器喷洒农药来控制这些病虫害。在应用场景范围内，喷雾覆盖、沉积和剖面定义不明确，限制了可以提供给种植者以最大限度地控制同时最大限度地降低投入成本的建议。为了探索喷雾器设置参数（例如行进速度和喷雾体积率）对高目标喷雾覆盖率的影响，我们建立了一个系统（一个简单的垂直图案器），使用一根 19 米高的杆，并在 5 至 5 的八个高度级别上附有卡片离地面 19 m，可以确定两个具有不同排气系统的气吹式喷雾器的垂直分布模式。在六种处理过程中，使用标准径向流式鼓风喷雾器进行喷雾，两种处理速度的组合：2.4 和 3.2 km/h，以及三种喷雾体积率：470、940 和 1970 L/ha，以及集中气流系统（蜗壳）喷雾器在四种处理过程中是两种行进速度的组合：2.4 和 3.2 km/h，以及两种喷雾量率：470 和 940 L/ha。结果表明，使用标准径向气流喷雾器时，喷洒量会影响高度 ≤ 17 m 的覆盖范围（喷洒量越大，覆盖范围越大）。使用标准径向气流喷雾器的更高速度导致更大的喷雾覆盖范围，但与集中气流系统不一致。与标准径向气流喷雾器相比，使用集中气流系统时，喷雾覆盖范围大于 17 m。使用标准的径向气流喷雾器，喷雾覆盖率曲线证实了覆盖率随高度的快速下降。结果可能有助于指导关于蜗壳使用、喷洒量和喷洒到树冠不同部分的决策，以改善喷洒剖面特征，从而将更均匀的喷洒覆盖范围应用于成熟的山核桃树冠层。