Impact des nécroses de la hampe sur les maladies de conservation de la banane dessert en agriculture biologique

Abstract

The dessert banana is one of the most important fruit crops for global food security. Unfortunately, it faces numerous phytopathogenic agents, including Fusarium spp. and Colletotrichum musae, which lead to post-harvest diseases. Several sources of contamination have been identified in the field and storage facilities in the literature. However, no study has been conducted regarding vascular contamination through the ascent of necroses from the tip of the floral stalk. The two objectives of this master thesis are to assess the impact of stalk necroses on the development of post-harvest diseases and, potentially, to propose an alternative method of stalk cutting to reduce the prevalence of these post-harvest diseases. For the first objective, samples were collected from necrotic areas at the tip of the stalk, inside the stalk, and from crown rot, and fungal strains were isolated. Our study suggests that the pathogen Fusarium sp. has a high likelihood of causing post-harvest diseases by contaminating the bunch through the tip of the stalk. For the second objective, four cutting alternatives were implemented in the field. The results show that the umbrella cut is a better alternative than the conventional cut because it prevents the ascent of necroses to the harvested fruits. Moreover, this cutting method enhances resistance to Fusarium sp. and C. musae, with reduction percentages of crown rot by 40% and 24% respectively. This is attributed to a 27% higher concentration of total polyphenols in the fruit skin compared to the conventional cut.