**9. Seed disinfection treatments**

Methods that are used in large-scale commercial seed production are mostly based on various chemical treatments—1–9% hydrochloric acid HCl, 1–5% calcium hypochlorite Ca(OCl)<sup>2</sup> , 1–3% sodium hypochlorite NaOCl, tetramethylthiuram disulfide (TMTD) (CH<sup>3</sup> )2 NCSS<sup>2</sup> CSN(CH<sup>3</sup> )2 , and the most commonly used in commercial seed production 10% trisodium phosphate (TSP) Na3 PO<sup>4</sup> mentioned above [5, 143]—which have been reported to provide satisfactory control of tobamoviruses in cucurbit [144] and solanaceous seeds (e.g., pepper [5, 145, 146] and tomato [147]). In addition to the chemical treatments, several heat treatment protocols at various temperature conditions ranging from 72 to 76°C for a minimum of 12 h up to 72 h [144] are also applied in large-scale production.

However, the recent global outbreaks of *Tobamovirus* diseases emphasize the incompetence of conventional seed disinfection treatments, which could be explained by the preservation of the virus in the inner tissues of the seeds [5]. Analyzing the efficacy of sequential treatments of 10% TSP followed by 72 h heat treatment at 72°C showed that CGMMV infectious particles are preserved in the seeds (**Figure 3**(**d–e**)) [34].
