Department of Agricultural, Food and Environmental Sciences, Marche Polytechnic University, Via Brecce Bianche, 60131 Ancona, Italy.
Ferdowsi University of Mashhad, Mashhad, Iran.
Plant Dis. 2021 Oct;105(10):3261-3268. doi: 10.1094/PDIS-06-20-1268-RE. Epub 2021 Nov 23.
Grapevine downy mildew (GDM) is one of the most serious diseases of grapevines. Limitations to the use of copper-based products in organic agriculture according to the European Union (EU) regulation EU/2002/473 and the later EU Commission implementing regulation 2018/1981 have promoted a search for alternatives. This 5-year field trial evaluated the effectiveness of several strategies against GDM using different chitosan-based formulations and application rates in comparison with other natural compounds applied individually or with copper hydroxide. Trials were performed in commercial vineyards with different environmental conditions and grapevine cultivars. For the natural compounds applied as individual treatments, a 0.5%/0.8% chitosan formulation provided the best protection against GDM; the other compounds and formulations were less effective. When copper hydroxide use was halved by combining it with the natural compounds according to three different strategies, the GDM incidence, severity, and McKinney index were reduced, particularly for copper hydroxide applied in combination with the 0.5%/0.8% chitosan formulation. The 0.5%/0.8% chitosan formulation alone and with copper hydroxide provided good protection against GDM during both high-pressure and low-pressure disease seasons. Therefore, chitosan represents a good alternative to copper formulations for the control of GDM and both organic and integrated disease management.
葡萄霜霉病（GDM）是葡萄藤上最严重的疾病之一。根据欧盟（EU）法规 EU/2002/473 和后来的欧盟委员会实施法规 2018/1981，有机农业中铜基产品的使用受到限制，这促使人们寻找替代品。这项为期 5 年的田间试验评估了使用不同壳聚糖基配方和应用率的几种防治 GDM 的策略的有效性，这些策略与单独或与氢氧化铜一起应用的其他天然化合物进行了比较。试验在具有不同环境条件和葡萄品种的商业葡萄园进行。对于作为单一处理剂施用的天然化合物，0.5%/0.8%壳聚糖配方对 GDM 提供了最佳的保护；其他化合物和配方的效果较差。当根据三种不同策略将氢氧化铜的使用减半并与天然化合物结合使用时，GDM 的发病率、严重程度和 McKinney 指数降低，特别是对于与 0.5%/0.8%壳聚糖配方结合使用的氢氧化铜。0.5%/0.8%壳聚糖配方单独使用和与氢氧化铜一起使用在高压和低压病害季节都能很好地防治 GDM。因此，壳聚糖是防治 GDM 的铜制剂的良好替代品，适用于有机和综合病害管理。
