Application of tracking implants in grape hybrids: Adjustments to production practices and new health-compliant methodologies

In order to adapt tracking implants in grapevine to production practices, four rootstocks belonging to two common Vitis hybrids [V. berlandieri x V. riparia (420 A, Kober 5BB, SO4) and V. berlandieri x V. rupestris (1103 Paulsen)] were tagged with radio frequency tags using the available methods: direct drilling of the pith from the distal cut of the rootstock or a ''U'' cut performed laterally on the rootstock below the grafting point. Tests were also combined with hot water treatments against phytoplasmas or applied to oneyear- old grafted rootlings ready for transplantation in the vineyard to reduce tagging costs. In addition, novel health-compliant methodologies for ultra-high frequency (UHF) tagging were evaluated. To assess the effects of tag implantation in rootstocks, plant viability, functional vascular tissue area and tag reliability were calculated, as well as the effects of phytopathogenic fungi on wounds produced by tagging. The tagging procedure did not cause significant effects on viability and functional vascular tissue area. Tag reliability was set at more than 96%. Fungal infections caused less than 1% of infected vascular tissue area and tagging methods could be integrated with hot water treatments against phytoplasmas. Tracking implants were applied successfully to one-year-old rootlings that were ready for transplantation, even if tag reliability decreased. Novel semi-internal implants of UHF tags did not cause concerns about plant health but tags were exposed to environmental stress or fortuitous damage during farming practices.