Effect of temperature on the growth of Geotrichum candidum and chemical control of sour rot on tomatoes

• Published in: Tropical plant pathology 2021-10, Vol.46 (5), p.545-552
• Main Authors: Thomidis, T., Prodromou, I., Farmakis, A., Zambounis, A.
• Format: Article
• Language: English
• Subjects: Biomedical and Life Sciences; Chemical control; Conidia; Fludioxonil; Fruit rot; Fruits; Fungicides; Geotrichum candidum; Germination; Life Sciences; Mycelia; Original Article; Pathogens; Pesticides; Plant Pathology; Propiconazole; Sour rot; Temperature effects; Tomatoes
• ISSN: 1983-2052; 1982-5676; 1983-2052
• DOI: 10.1007/s40858-021-00453-1

Geotrichum candidum is an important pathogen causing sour rot in fruit and vegetables. In this study, G. candidum was identified as a pathogen causing postharvest tomato fruit rot for the first time in Greece. The effect of temperatures and incubation period on the mycelial growth and conidia germination of G. candidum was investigated. It was also found that the optimum temperature for the mycelial growth and conidia germination of G. candidum was 25°C, while this pathogen was also very active at temperatures between 15 and 30°C. Incubation at 40°C inhibited mycelial growth and conidial germination of G. candidum . Conidia germinated after an 8-h incubation period with a higher percentage after 16h. In addition to the above studies, the effectiveness of fludioxonil and propiconazole against G. candidum was evaluated. EC 50 values of G. candidum isolates for propiconazole ranged from 0.050 to 0.250 μl/ml, while this fungicide inhibited the growth of the fungus on tomatoes. In contrast, the EC 50 values for the effect of fludioxonil were 3.057 to 3.891μg/ml, while this fungicide was not effective against G. candidum on tomatoes. Generally, this study showed G. candidum as a new threat for tomatoes in Greece. This pathogen can develop in a wide range of temperatures. Propiconazole seems to be an effective fungicide against G. candidum in tomatoes.