Use of different spray volumes and hydraulic nozzles in air-assisted electrostatic insecticide application technologies to control coffee berry borer (Hypothenemus hampei) populations

ABSTRACT. Chemical control is essential for efficient pest management in coffee crops. Application technologies should safely deliver insecticides to the target whilst protecting the environment, insecticide applicators, and consumers. To achieve these goals, application volumes, hydraulic nozzles, and application techniques should be evaluated. This study assessed the biological efficiency of different spray volumes and spray nozzles used to apply insecticides to control coffee berry borer (Hypothenemus hampei) populations. We applied insecticides using a hydropneumatic sprayer with and without an electrostatic spraying system. The experiment followed a randomized block factorial design (2 × 2 + 1) and included two types of spray nozzles [a hollow cone spray nozzle (JA1) and a hollow cone spray nozzle with air induction (TVI)], two spray volumes (200 and 400 L ha-1), one additional treatment (SPE2 nozzle with a 200 system 200 L ha-1), and six replicates. We assessed the control efficiency of the different application methods by evaluating the percentage of fruits damaged 20 and 40 days after the date of application. The spray volume did not affect the biological efficiency of pest control, and the lower spray volume (200 L ha-1) was effective in the control of coffee berry borers. Application of insecticides using coarse droplets was more efficient than the application using very fine and fine droplets. The TVI hydraulic spray nozzle effectively controlled coffee berry borers at 200 and 400 L ha-1. The electrostatic application system performed similarly to the conventional system in terms of the control of the coffee berry borers, and was less efficient than the conventional system under some operational conditions.

摘要
化学防治是实现咖啡作物高效害虫管理的关键技术手段。施药技术需将杀虫剂安全输送至靶标区域，同时保障环境、施药人员与消费者的安全。为达成上述目标，需对施药剂量、液压喷嘴及施药工艺开展系统评估。本研究针对用于防控咖啡果小蠹（Hypothenemus hampei）种群的不同喷雾剂量与喷雾喷嘴的生物防控效能展开评价。实验采用气液两用喷雾器（hydropneumatic sprayer），分别搭载与不搭载静电喷雾系统（electrostatic spraying system）完成杀虫剂喷施。实验采用随机区组析因设计（randomized block factorial design，2 × 2 + 1），设置两类喷雾喷嘴：空心锥形喷雾喷嘴（hollow cone spray nozzle，JA1）与带空气诱导功能的空心锥形喷雾喷嘴（hollow cone spray nozzle with air induction，TVI），两种喷雾剂量（200 L·ha⁻¹和400 L·ha⁻¹），额外增设1组处理（SPE2喷嘴搭配200 L·ha⁻¹施药剂量），并设置6次重复。本研究通过测定施药后20天与40天的果实受害率，评价不同施药方式的防控效能。结果表明：喷雾剂量对害虫防控的生物效能无显著影响，较低施药剂量（200 L·ha⁻¹）即可有效防控咖啡果小蠹；采用粗雾滴喷施的防控效果优于细雾滴与极细雾滴喷施；TVI型液压喷嘴在200 L·ha⁻¹与400 L·ha⁻¹施药剂量下均可实现对咖啡果小蠹的有效防控；静电喷雾系统的防控效能与传统施药系统相当，但在部分作业条件下其防控效能略低于传统系统。