More than 360 plant samples were collected from symptomatic and asymptomatic cultivated crops (including barley, wheat, oats, potato, rye, beet, faba bean, peas, lupin and pasture swards) and processed using an RNA sequencing workflow optimised during a pilot comparison of enrichment and bioinformatics methods; sequence data were generated for 80+ samples and analysed with validated pipelines. All raw sequence data and assembled viral genomes have been deposited in public repositories (SRA, GenBank) and collated into an open, central database of Irish plant virus sequences, made available on Zenodo to support reuse by researchers and diagnosticians. A landscape reservoir study collected and pooled over 300 individual plants from arable margins, hedgerows and pastures into plant‑community samples, confirming that grasslands and pasture are important reservoirs of cereal‑relevant yellow dwarf viruses (including the species dominant in spring barley), and sampling of margins led to the first record of soybean dwarf virus (SbDV) in Ireland, detected in red and white clover. Four alternative tuber crops (yacon, oca, Chinese artichoke, Jerusalem artichoke) were screened and no high‑risk pathogens (e.g. potato yellowing virus) were found. Beet yellows virus (BYV) was identified as causing yellowing in fodder beet, prompting development and publication of a rapid, field‑amenable RT‑LAMP assay for BYV. Finally, a secondment to a national plant‑health laboratory produced a case study and report on implementing high‑throughput sequencing (HTS) for routine diagnostics.