Additive and synergistic antifungal effects of copper and phenolic extracts from grape cane and apples

Background

Organic viticulture seeks sustainable alternatives for eco-toxic copper fungicides to control downy mildew caused by Plasmopara viticola. (Poly)phenol-rich extracts of agricultural byproducts are known to possess antifungal activity, but high production costs often limit their actual implementation.

Results

We developed and produced novel ligninsulfonate-based grape cane extract (GCE) formulations and an apple extract on a pilot plant scale, including a detailed (poly)phenol characterization by high-performance liquid chromatography photodiode array mass spectrometry (HPLC-PDA-MS). Our GCE formulations alone reduced downy mildew disease severity in greenhouse trials by 29%–69% in a dose-dependent manner, whereas a standard application of the copper-based agent alone reached ~56%. When applied together, disease severity was diminished by 78%–92%, revealing a synergistic effect that depended on the mixture ratio. Combining GCE formulations with the apple extract, additive effects were found (80% disease severity reduction).

Conclusion

The studied plant extracts are proposed to both substitute for and synergistically reinforce copper fungicides in grapevine downy mildew control. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

德国提高奶牛养殖业经济效益的措施

现在，德国总共饲养有430万头奶牛。所有的农场都是私人独有的，但经营结构各不相同。有的奶牛场只有10-15头奶牛，有的奶牛场拥有1500-1800头奶牛。在德国南部，牛奶主要由规模为25头的奶牛场提供，而北部的规模约为60头，东部的规模在240头左右。