The control of soil-borne fungal pathogens in grapevine nurseries in Türkiye and their impact on sapling quality

In the production of grafted vines, losses are caused by fungal pathogens during callus forming or after planting in the soil. To control or reduce natural soil-born fungal infections in nurseries, certain applications were conducted in the sapling cultivation stage to analyse the efficacy of cyprodinil + fludioxonil, fluopyram + tebuconazole active substances, and Trichoderma harzianum biological preparation: 1103 Paulsen rootstock and Vitis viniferea L. cv. In the study, Sultana cultivars were stored in fungicide suspensions for 60 min before and after grafting. After grafting, the saplings were divided into (i) cutting + sawdust (ii) cutting + sawdust + soil application groups and transferred to the callus room. After nine months in the nursery, the plants were uprooted, classified as diseased or healthy, and analysed for morphological and molecular diagnosis of fungal species, isolation incidence, and sapling quality and yield. Boeremia exigua var. exigua was isolated for the first time from cuttings during grapevine sapling production and was first registered in NCBI Genbank. After callus development, Fusarium solani was most frequently isolated pathogen in the roots (21.5%); cyprodinil + fludioxonil reduced the Ilyonectria sp. isolation rate in both shoots and roots. Botryosphaeria dothidae and I. liriodendri pathogens were not detected in disease and healthy cyprodinil + fludioxonil treated saplings. The highest sapling yield was observed in fludioxonil + cyprodinil, cutting + sawdust + soil (78.75%) and cutting + sawdust (70.63%) applications.