Enhancing IPM implementation perspectives in Montenegro and Italy by means of a dynamic mechanistic model for Phomopsis viticola infections: VITISUST

Phomopsis cane and leaf spot disease is one of the most important grapevine diseases in Montenegro. It occurs every year and causes considerable damage. At the beginning of growing season, the disease leads to unequal opening of buds and often causes their destruction. Recently a bilateral project for ‘Italy–Montenegro Joint Science And Technology Cooperation’ in the area Agriculture and Food Sciences was settled up in order to develop and calibrate a new model for Phomopsis cane and leaf spot disease (PCLS), which is widespread in Montenegro and of increasing importance in Italy. The VITISUST Project is supported by Foreign Affairs Ministry and Ministry of Science in both Countries. In 2018 studies about overwintering structures of the pathogen were carried out, then a model prototype was developed and in 2019 specific trials for monitoring disease dynamic and starting the model evaluation have been carried out. The disease assessment was performed on typical varieties Barbera and Vranac in Italy and Montenegro, respectively, both trained at double guyot by mean of a visual assessment at dormant stage (i.e. presence and type of symptoms on canes) and during the growing season (i.e. symptoms appearance on leaves and shoots). First symptoms were observed 22 and 19 days after bud break in Montenegro and Italy, respectively, and the disease incidence reached 54,3% and 50,5% of the observed canes, respectively. The highest disease severity was observed on shoots at the beginning and at the end of the old cane (curved down) while the shoots developed from the buds located on the top of the cane curve resulted not affected. This could be explained with the stem-flow effect caused by rainfall that floods pycnidia at the top cane positions and spread the pycnidiospores.