Agro-morphological response of some groundnut genotypes (Arachis hypogaea L.) in water deficit conditions

Groundnut is a crop that can be grown under varied production conditions (in intercropping or rotation with cereals). In Niger, the production of groundnut is decreasing over the year due to drought and low soil nutrients. In this work, an agro-morphological evaluation of five groundnut genotypes (55-437, ICG12697, ICG4750, JL24 and ICG8751) under water deficit was carried out in order to identify the best performing genotypes for seed and forage production. Intermittent water deficit was imposed from the 53rd day after sowing, which was the beginning of pod filling. The other plants were well watered until harvest. The results showed that in water stress conditions all yield parameters (pod number, pod weight, seed number, seed weight, harvest index and pod filling rate) and vegetative parameters (aerial biomass and height) with the exception of the number of branches decreased. The principal component analysis revealed that genotypes with a good harvest index and high pod filling rate have good seed yield. Therefore, harvest index and filling rate can be used for the selection of genotypes under water stress conditions. The genotypes 55-437, ICG4750 and ICG12697 proved to be the best performers under water stress and well-watered conditions. These ones accumulate vegetative biomass as proportionate way to the production and filling of the seeds in contrast to JL24 and ICG8751, which tend to accumulate vegetative biomass to the detriment of the production and filling of pods. Key words: Agromorphologic, yield, groundnut, water deficit, Niger.