Controlling effect by non-QoI fungicides against grape ripe rot in the immature fruit stage

Abstract

We examined the effects against the grape ripe rot (Glomerella cingulata (Stoneman) Spaulding & H. Schrenk (anamorph: Corretotrichum groeosporioides Penzig & Saccardo)), by spraying several fungicides including non-QoI (Quinone outside Inhibitors) fungicides and QoI fungicides. The cultivar of berries used in this experiment were “Kyoho” (Vitis vinifera L. × Vitis labrusca L. cv. Kyohou), and we sprayed fungicides in June to July, when the pathogen scatters most spores.

In 2015, 2016 and 2017, we sprayed each fungicides two times to the grape trees, leaves, and fruits at the immature fruits stage and influence on the fruits bloom by the fungicides were researched. And in 2016 and 2017, we measured the number of berries which infected by the grape ripe rot in the mature stage. As a result, in our experiments, the most effective fungicide is azoxystrobin (Amistar 10 flowable; Syngenta Japan, Inc.), followed by pyraclostrobin-boscalid (Naria WDG; BASF Japan, Inc.), captan (Orthocide 80; Arysta Life Science, Inc.), and penthiopyrad (Affet flowable; Mitsui Chemicals Agro, Inc.) in order.

Additionally, we also examined the influence of each fungicides to the berries in the mature stage. As a result, the bloom leaching appeared after pyraclostrobin-boscalid sprayed when berries were as large as the size of soybeans. However, 2016 and 2017, bloom leaching did not occur after spraying when berries size were as large as adsuki beans.