Assessing the Impact and Causes of Rice Panicle Necrosis in Côte d’Ivoire

Abstract

Rice is a staple food for millions of people around the world, particularly in Côte d'Ivoire. Its production is subject to numerous biotic constraints, including rice panicle necrosis. Rice panicle necrosis, previously neglected, has taken on worrying proportions in Côte d'Ivoire's rice-growing basins over the past half decade. The aim of this study is to diagnose rice panicle necrosis in Côte d'Ivoire. A phytosanitary survey was conducted in rice-growing basins across three agroecological zones of Côte d'Ivoire in order to describe the symptoms of rice panicle necrosis and assess its importance. The fungi responsible for rice panicle necrosis were identified. Rice panicle necrosis is characterized by the development of grain necrosis and the development of thin, empty grains on the panicles. Rice panicle necrosis was found in all agroecological zones, with the highest prevalence (58.49 to 72.21%), severity index (72.32 to 85.27%), and production loss (48.70 to 54.75%) in the Divo and Gagnoa rice-growing basins. Three species of Fusarium, including Fusarium fujikuroi, Fusarium verticillioides, and Fusarium proliferatum, are responsible for rice panicle necrosis in Côte d'Ivoire. It is important to assess the impact of these fungi on rice production in order to design a program to manage rice panicle necrosis.