Meteorological Conditions in a Temperate Climate for Colletotrichum acutatum, Strawberry Pathogen Distribution and Susceptibility of Different Cultivars to Anthracnose

Abstract

Previously, Colletotrichum spp. has been considered a warmer climate pathogen as these meteorological conditions are most optimal for its development. However, climate change is fostering the spread of plant disease and complicating the ability to predict meteorological conditions for disease development. This study aims to determine meteorological conditions for anthracnose development, evaluate the susceptibility of different strawberry cultivars and detect the distribution of strawberry pathogens in temperate climate conditions. The experiment was carried out in the Institute of Horticulture Lithuanian Research Centre for Agriculture and Forestry (LAMMC) in Lithuania during the 2018–2019 strawberry growing season. To evaluate the contamination levels (fungal and bacterial pathogens) of strawberry plant parts, soil and susceptibility to Colletotrichumacutatum, samples were collected at four different locations in Lithuania from eleven cultivars. The results revealed that Colletotrichum spp. was not equally prevalent in the soil at all strawberry farms tested. The evaluation indicated that strawberry leaves and stems were similarly contaminated with pathogenic fungi. The most frequently isolated fungi from the leaves and stems were Mycosphaerella spp., Alternaria spp., Fusarium spp., Colletotrichum spp., Phytophthora spp., and Botrytis spp. Our study confirmed that the response of cultivar susceptibility to C. acutatum was unequal. The most suitable temperature for C.acutatum development was 25 °C. Monitoring of meteorological conditions, evaluation of inoculum source and appropriate cultivar selection could reduce or avoid yield losses caused by the C. acutatum.