Department of Plant Pathology and Environmental Microbiology, The Pennsylvania State University, Lake Erie Regional Grape Research and Extension Center, North East, PA 16428.
Department of Plant Science, The Pennsylvania State University, University Park, PA 16802.
Plant Dis. 2024 Oct;108(10):3156-3162. doi: 10.1094/PDIS-02-24-0383-RE. Epub 2024 Oct 7.
Late-season bunch rot can cause substantial yield loss in grapevines grown in humid regions. Fruit-zone leaf removal has been widely used to reduce bunch rot and pesticide applications through improvements in canopy microclimate and grape cluster morphology. In this study, we evaluated whether mechanical leaf removal can be a valid alternative to a labor-intensive manual application by comparing prebloom manual (PB-MA) and mechanical (PB-ME) leaf removal. We also evaluated the effects of the timing of mechanical application, prebloom (PB-ME) versus fruit set (FS-ME), on fruit traits and bunch rot, caused by . Our trials were conducted on two 'Pinot noir' and 'Pinot gris' vineyards in the Northeastern United States over two seasons (2017 to 2018). Major findings were overall consistent between cultivars and years. Leaf removal provided reductions in fruit-zone canopy density regardless of method or timing. In general, PB-ME provided similar shifts in cluster morphological traits to PB-MA, including lower number of berries per cluster, cluster compactness, and cluster weight compared with control (no leaf removal) vines. At harvest, both prebloom leaf removal methods equally reduced Botrytis bunch rot severity, whereas Botrytis bunch rot incidence in Pinot noir was lowest for PB-ME in 1 year and PB-MA in the next year. When comparing timing of mechanical leaf removal, FS-ME provided Botrytis bunch rot reductions similar to PB-ME, without effects on cluster weight. Thus, under our growing conditions, FS-ME was considered the best mechanical leaf removal option to help manage Botrytis bunch rot without causing undesirable yield reductions.
晚季穗轴腐烂病会导致在潮湿地区种植的葡萄藤大量减产。去除果穗区叶片通过改善冠层微气候和葡萄串形态，已被广泛用于减少穗轴腐烂病和农药的使用。在这项研究中，我们通过比较开花前手动（PB-MA）和机械（PB-ME）去除叶片，评估了机械去除叶片是否可以替代劳动密集型的手动应用。我们还评估了机械应用时机（开花前 PB-ME 与坐果期 FS-ME）对. 引起的果实特性和穗轴腐烂病的影响。我们的试验在美国东北部的两个葡萄园（2017 年至 2018 年）进行，分别是'黑比诺'和'灰比诺'两个品种。主要发现结果在两个品种和两年中总体一致。无论方法或时间如何，去除叶片都能减少果穗区冠层密度。一般来说，PB-ME 与 PB-MA 相比，提供了类似的集群形态特征变化，包括每串浆果数量减少、集群紧凑度提高和集群重量减轻。在收获时，开花前两种叶片去除方法都同等降低了灰霉病穗轴腐烂的严重程度，而在一年中，黑比诺的灰霉病穗轴腐烂发生率最低的是 PB-ME，第二年则是 PB-MA。在比较机械叶片去除的时机时，FS-ME 提供了与 PB-ME 相似的灰霉病穗轴腐烂病减少效果，而不会影响集群重量。因此，在我们的生长条件下，FS-ME 被认为是最好的机械叶片去除选择，可以帮助管理灰霉病穗轴腐烂病，而不会导致不必要的产量降低。
