Effect of Sowing Date on the Agronomic Performance of 14 Accessions of Senna obtusifolia (L.) Irwin and Barneby from Burkina Faso

Abstract

Background and Aims: Long considered in Burkina Faso as a ruderal plant or a crop weed, Senna obtusifolia also known as casse fétide in French or Katr-nanguri in the Mooré language is now recognized for its food, medicinal, and economic potential. It is used in both human and animal diets and serves as a source of income for rural communities. The present study aimed to determine the effect of sowing date on the agronomic performance of 14 accessions of Senna obtusifolia. Study Design: The trials were conducted using a randomized complete block design (RCBD), with three replicates. Place and Duration of Study: The present study, was conducted at the Tenkodogo University Center, between July and November 2025. Methodology: we sowed 14 accessions of Senna obtusifolia on July 12 and August 12, 2025, on sandy-clay soil low in organic matter. The replications were separated by a distance of 2.3m. Days to emergence (DE), days to flowering (DF), plant height at maturity (PHM), stem diameter (SD), leaf length (LL), Fresh leaf biomass (FLB), fruit length (FrL), fruit width (FrW), number of fruits per plant (NFrP), number of seeds per fruit (NGFr), number of seeds per plant (NSP) were measured and analyzed. Results: July sowings outperformed those in August, with an 80% increase in the number of fruits per plant (NFrP), along with higher flowering and fruit-filling rates. Hierarchical cluster analysis grouped the accessions into three clusters, with Cluster 2 containing accession G-E2, which exhibited superior agronomic performance. This accession is characterized by high leaf biomass and a strong capacity for fruit and seed production. Its consistent performance suggests marked phenotypic plasticity and good adaptation to environmental variations, particularly those related to sowing date. Conclusion: These results confirm that accession performance varies with sowing date, a variability that can be exploited in plant breeding. Early sowing is recommended to optimize leaf and seed production, likely due to more favorable rainfall conditions during the early growth stages.