Abstract

Mycosphaerella blight, caused by Peyronellaea pinodes (Berk. & A. Bloxam) Aveskamp, Gruyter & Verkley (syn. Mycosphaerella pinodes (Berk. et Blox.) Vesterg.), is a destructive foliar pathogen of field pea that is managed, in large part, through application of foliar fungicide at flowering. The fungicides are usually applied into dense crop canopies, so reaching the lower areas of the canopy where the pathogen is initially most active is a challenge. Field trials were conducted across the Canadian prairies from 2008 to 2011 to assess the efficacy of various nozzle numbers and orientations, droplet sizes, and water volumes for the management of Mycosphaerella blight to increase yield in field pea. Pea plants were assessed for disease severity during flowering and seed yield was measured. In 10 of the 13 trials, double-nozzle configurations provided a 15% reduction in disease severity and up to a 60% increase in yield. In contrast, droplet size and angle of application had no effect on field pea yield. Water volume trials using up to 400 L ha⁻¹ improved fungicide efficacy relative to control treatments, however, volumes above 400 L ha⁻¹ resulted in high-disease severity and lower yield, likely as a result of fungicide run-off due to saturation of the leaf surface. When deciding on effective sprayer techniques for fungicide application, disease pressure, environmental conditions and cultivar characteristics are important to consider.

摘要

Mycosphaerella Blight，由Peyronellaea pinodes (Berk. & A. Bloxam) Aveskamp, Gruyter & Verkley (syn. Mycosphaerella pinodes) 引起(Berk. et Blox.) Vesterg.)，是豌豆的一种破坏性叶面病原体，主要通过在开花时施用叶面杀菌剂来控制。杀菌剂通常应用于密集的作物冠层，因此到达病原体最初最活跃的冠层下部区域是一个挑战。从 2008 年到 2011 年，在加拿大大草原上进行了田间试验，以评估各种喷嘴数量和方向、液滴大小和水量对控制球孢霉病以增加豌豆产量的功效。在开花期间评估豌豆植物的疾病严重程度并测量种子产量。在 13 项试验中的 10 项中，双喷嘴配置使疾病严重程度降低了 15%，产量提高了 60%。相比之下，液滴大小和施用角度对豌豆产量没有影响。使用高达 400 L ha 的水量试验^-1相对于对照处理提高了杀真菌剂的功效，但是，超过 400 L ha ^{-1 的}体积导致高病害和较低的产量，这可能是由于叶表面饱和导致杀真菌剂流失的结果。在决定用于杀真菌剂的有效喷雾器技术时，病害压力、环境条件和品种特性是重要的考虑因素。