Striga gesnerioides (Willd.) Vatke infestation and distribution as affected by soil properties and varieties at the plot and landscape scales in cowpea‐based cropping systems

Early Access ; International audience ; Striga is among the most noxious parasitic plant genera causing yield losses to staple crops in the semiarid and subhumid areas of Africa and Asia. Understanding the factors that affect the current distribution of Striga infestation is critical for developing integrated control strategies. This study attempts to elucidate the soil properties that are related to and that affect the plot-level infestation and land-scape level distribution of Striga gesnerioides (Willd.) Vatke in Niger. At the plot scale, 27 cowpea varieties were sown in randomised blocks of 30 plots in 14 fields, and their soils were sampled and analysed. S. gesnerioides infestations were recorded in the fields over 2 years. These records were obtained with georeferenced data, and soil properties were extracted from global databases. At the plot scale, the variance in S. gesnerioides infestations were affected by available phosphorus (29.17%), organic carbon (16.61%), pH (15.15%), nitrogen (13.13%), and sand contents (10.12%) and varied among the cowpea varieties. This led to the identification of cowpea varieties with consistent high levels of resistance (varieties: CS030 and CS095). At the landscape scale, soil moisture is the key factor explaining 48.6% of S. gesnerioides distribution, followed by silt content (28.1%), sand content (13.7%), and bulk density (6.2%). These results showed a clear dichotomy in the interactions between the occurrence of S. gesnerioides and soil properties from the plot to landscape scales. These results are valuable for understanding the ecology of S. gesnerioides and can support the development of integrated control strategies.