The Control of Fungal Pathogens in Grapevine Nurseries in Türkiye and Their Impact on Sapling Quality

Abstract

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 fungal infections in nurseries, certain applications were conducted in sapling cultivation stage to analyse the efficacy of cyprodinil + fludioxonil, floupyram + tebuconazole active substances and Trichoderma harzianum biological preparation. 1103 Paulsen rootstock and Vitis viniferea L. Sultana cultivars were stored in fungicide suspensions for 60 minutes before and after grafting in the study. After grafting, the seedlings were divided into i) cutting + sawdust ii) cutting + sawdust + soil application groups and transferred to the callus room. Fungicides were applied 1 to 7 days after the callus development to wet the seedling roots 1 to 7 days after they were planted. 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 seedling quality and yield. 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 obtusa and I. liriodendri pathogens were not detected in sick and healthy cyprodinil + fludioxonil-treated saplings. The highest seedling yield was observed with fludioxonil + cyprodinil, cutting + sawdust + soil (78.75%) and cutting + sawdust (70.68%) applications. According to the results of this study, it was found that fungicide applications before and after grafting prevented soil-borne pathogen infections and improved sapling quality.