The cause for the erratic yields of the two main almond cultivars grown in Morocco has been searched in order to recommendpossible solutions for a high and stable production. The lack of sufficient bloom overlap between ‘Marcona’ and ‘Fournat de Brézenaud’in many years may be one of the reasons of this erratic behavior, but not the only one, as the same behaviour may be observed in twosimultaneously blooming cultivars, ‘Ferragnès’ and ‘Ferraduel’. The relatively high temperatures observed during the blooming periodsignificantly reduced the stigma receptivity of these cultivars and, as a consequence, their effective pollination period, showing that stigmaticreceptivity is a limiting factor for fruit set in ‘Marcona’ and ‘Ferragnès’ and their subsequent yield reduction under warm conditions. Thus, inthe present context of global warming, the search for cultivars tolerant to heat stress during flowering will acquire a special interest, as wellas the combination of cultivars with the same chilling and heat requirements to ensure a simultaneous bloom
