Prospection and Collection of Striga hermonthica Ecotypes and Cultivated Millet in Niger: Towards Improved Control Strategies

Abstract

Among the dominat food crops (millet, sorghum, cowpea), millet holds a central place in the national food security strategy. However, production remains insufficient to meet the population's needs. This productivity gap is attributed to various biotic and abiotic factors  among whhich Striga hermonthica represents one of the major constraints. The main objective was to study the morphological diversity of local millet varieties and Striga ecotypes collected across different regions of Niger and to analyze their relationship with observed infestation levels, with the aim of contributing to the selection of resistant cultivars and improving control strategies against this parasite. Between October and November 2021, several prospection and collectionmissions for Striga ecotypes and the millet seeds form which they originated were successively conducted in five surveyed regions of Niger, covering the country's three main infestation zones. Samples were collected based on farmer availability and seed maturity. A total of 25 millet varieties and 25 Strga ecotypes were gathered. The collectd data were entered into Excel 2010, and for indepth analysis, RStudio 4.2.3 was used. Millet seeds exhibited variations in color, shape, and size depending on the region. Striga infestation in the surveyed fields was widespread, with significant levels dominating (40-60% of fields). Maradi and Zinder experienced the most severe infestations (40% highly significant cases). Principal Component Analysis (PCA) revealed that infestation levels did not affect seed size/weight 100. The first two principal components accounted for 91.5% of the total variance in the dataset, which is highly significant. The findings form this study offer promising prospects for enhancing millet productivity and strengthening food security in affected areas.