Sheep Manure as a Potential Source of Tomato Brown Rugose Fruit Virus and Composting as a Mitigation Strategy

Area of Science:

• Plant Pathology
• Virology
• Agricultural Science

Background:

• Tomato brown rugose fruit virus (ToBRFV) threatens global tomato production due to resistance-breaking properties.
• A novel transmission route via livestock ingesting infected plant debris was identified.

Purpose of the Study:

• To investigate livestock manure as a potential ToBRFV transmission pathway.
• To evaluate composting as a viable strategy for inactivating ToBRFV in agricultural waste.

Main Methods:

• Sheep were fed ToBRFV-infected tomato debris; manure was tested for viral RNA and infectivity.
• Aerobic composting of infected debris was conducted for 60 days under controlled thermophilic conditions.
• Post-composting bioassays and RT-qPCR were used to assess viral inactivation.

Main Results:

• ToBRFV RNA was detected in sheep manure, with bioassays confirming infectivity.
• Composting reached temperatures (60-70°C) sufficient for pathogen inactivation.
• No ToBRFV infectivity was observed in plants exposed to composted material, though residual RNA was detected.

Conclusions:

• Composting effectively inactivates Tomato brown rugose fruit virus (ToBRFV), rendering it non-infectious.
• This study validates composting as a sustainable and scalable solution for ToBRFV mitigation in agricultural waste management.
• Composting offers an environmentally friendly approach, especially where plant waste is recycled or fed to livestock.