Physiological quality of upright and prostrate growth cowpea seeds produced in Roraima state, Brazil

The physiological quality of seeds is important to obtain high crop yields. The aim of this study was to evaluate the physical and physiological quality of 16 upright growth habit lineages and 15 prostrate growth habit lineages of cowpea seeds produced in Roraima state, Brazil. Two trials were assessed: the first with 16 lineages and the second with 15 lineages. The study was carried out in a completely randomized experimental design with four replicates. After field operations of harvesting and threshing, seeds were assessed for mass of one thousand seeds and water content. The physiological quality of seeds was assessed with respect to germination rate, first germination count, electrical conductivity, plantlet emergence and plantlet emergence velocity in sand substrate. The results obtained showed that the seed breeding lines presented low water contents. MNCO2-682F-2-6 upright habit lineage showed better germination rate and vigor, while MNCO2-684F-5-6 lineage presented lower percentage of germination and emergence in sand substrate. MNCO1- 649F-1-3 prostrate habit lineage showed lower performance. Ten of the upright habit lineages and none of the prostrate habit lineages studied presented seeds with germination rates higher than 80%