Analysis of the relationship between start of the rainy season and farmer's sowing strategy in the Niamey area and its impacts on the pearl millet yield

International audience; Relationship between start of the rainy season and farmer's planting date have been analysed at local scale through in situ daily rainfall records and agronomical measurement provided by on-farm survey at plot scale for 10 villages network located on the mesoscale AMMA-CATCH Niger site during the 2004-2007 rainy seasons. Many classical empirical methods of monsoon onset dectection (e.g. Benoit, Kowal, Sivakumar, Ati, Marteau, Balme, Sultan) and numerical methods based on crop model SARRAH have been compared to the observed farmer's sowing date. Results show that SARRAH and Balme mean onset date are close to sowing date. But spatial and temporal variability of the sow…