Virus surveys of commercial vineyards show value of planting certified vines

Abstract

G rapevines have the highest number of viruses and virus-like diseases ever discovered in a single crop (Martelli 2014), and they may cost California wine grape growers as much as $91,661 per acre over the life of a vineyard (Ricketts et al. 2015) by affecting yield, color, sugar and other qualitative parameters (Goheen and Cook 1959). Some viruses are spread by insects and nematodes (Golino et al. 2002; Raski and Hewitt 1960), but human activities such as the propagation of infected material also distribute viruses into vineyards. Viruses are graft transmissible, meaning they can move from scion to rootstock, or from rootstock to scion during topworking (Alley and Golino 2000; Olmo 1951).

Studies on the Occurrence of Viruses in Planting Material of Grapevines in Southwestern Germany

“…One prerequisite for PCR and ELISA testing is to know at least part of the pathogen’s genetic code or protein structures. Undetected pathogens in plant material are distributed unintentionally and their occurrence is artificially upregulated [ 23 ]. The longer infected material is distributed unknowingly, the harder it becomes to contain the pathogen.…”

“…In particular, the results from 2018 show that the recently discovered GPGV emerged rather unnoticed to become the most widespread virus in German vineyards, as it is mostly latent in plants. Therefore, it should be considered whether it would not make sense to include viruses like GPGV or GRBaV in the vine planting material regulation, especially since the latter can easily be mistaken for leafroll in optical inspections [ 23 ]. In addition, it would be interesting to investigate to what extent GRBaV is already latent in grapevines in Germany.…”

Incidence and detection of negative‐stranded RNA viruses infecting apple and pear trees in California

“…A total of 186 samples (138 from apple and 48 from pear) were collected from 21 orchards. To account for potential symptomless nature and spatial patchiness in the incidence of viruses, sampled trees were arbitrarily selected following a W pattern in the field (Arnold et al, 2019; Madden et al, 2007). Samples were taken from 8 to 10 different trees for each orchard, and from each tree, six fully developed leaves were collected from different parts of the tree.…”

Returns to public investments in clean plant centers: A case study of leafroll virus-tested grapevines in support of cost-effective grape production systems

“…If left uncontrolled, pathogens can cause diseases that cost the grape industry billions of dollars annually (Mannini and Digiaro, 2017). Planting certified, clean vines derived from virus-tested (negative) foundation stocks minimizes the initial introduction of virus diseases into the vineyard (Arnold et al, 2019), which is key to cost-effective grape production (Golino et al, 2017). Clean plant material is also critical for the U.S. grape industry and other specialty crop industries to remain competitive globally.…”

“…Several studies have thoroughly examined the economic impact of GLRD in New Zealand (Walker et al, 2004; Nimmo-Bell and Company Limited, 2006), New York (Atallah et al, 2012), and California (Ricketts et al, 2015; Fuller, Alston, and Golino, 2019; Cheon et al, 2020). Grower costs of GLRD were estimated to range from $21,000 to more than $226,000 per hectare over a 25-year lifespan of a vineyard, depending on the level of infection, the timing of infection, price penalty for poor fruit quality, cultivar, and region of grape production.…”