Annual Medicago species in Morocco. I. Species and their abundance

Abstract

An ecogeographic survey of the distribution of annual medics in Morocco was conducted in 1988 by sampling 161 sites within six agricultural zones. At each site all medic pods lying on the soil surface were collected from five quadrats placed at random. Of the 18 medic species reported to occur in Morocco, only 11 were recorded in 1988. M. polymorpha and M. truncatula were the most frequent. Thirty-five sites had no medics in quadrats and 15 sites had no medics in the near vicinity. The average seed yield for all collection sites was 12.6 kg ha-1. Nearly 60% of the sites yielded less than 20 kg ha-1. More than 50 kg seed ha-1 was recorded at less than 10% sites. Maximum seed yield at any site was only of 169 kg ha-1. Results suggest that genetic erosion is occurring but occasional sites can be found where medics are abundant.