Finding Solutions to Manage Plant-Parasitic pests of Michigan Hopyards
- Research Date
- 2021
- Authors
- Marisol Quintanilla
- Priorities
- Pest Management
- Crop Categories
- Hops
Plant-parasitic nematodes, like the hop cyst nematode (Heterodera humuli), are understudied and likely posing a risk to worldwide hop production (Darling et al., 2022). Michigan hop growers often suffer from intense viral and fungal infections, insect and mite pest threats, and likely, plant-parasitic nematodes. These various pressures have been negatively impacting the Michigan craft beverage industry and severely prohibiting growers from receiving yields like the Pacific Northwest region. In this project, we investigated (1) the prevalence and distribution of economically significant plant-parasitic nematodes in Michigan hopyards, and (2) the impact of manure-based composted soil amendments on nematode populations, viral load, and cone yield. We identified ten genera in Michigan hopyards: Pratylenchus, Xiphinema, Heterodera, Helicotylenchus, Tylenchorhynchus, Paratylenchus, Meloidogyne, Criconema, Hoplolaimus, and Paratrichodorus. Root lesion nematodes, Pratylenchus spp., were the most prevalent plant-parasitic nematode genus, occurring in 96.4% of sampled hopyards. The hop cyst nematode, Heterodera humuli, was identified in 50% of Michigan hopyards. The pelletized poultry manure soil amendment significantly reduced root-lesion (Pratylenchus spp.) and dagger nematodes (Xiphinema spp.), in comparison to control plots. These plots had higher cone yield than non-applied control plots in both years, 2020 and 2021 (P>0.05). However, in both years, the proportion of viral reads detected was greatest in hop treated with layer ash blend. Our field trials suggest that pelletized poultry manure may be an effective soil amendment for reducing plant-parasitic nematodes, decreasing viral load, and increasing overall cone yield.