Potential Infestation Of Food Legumes By Orobanche Spp. In Moroccan Highlands

Kaddour Saffour
Centre Régional de la Recherche Agronomique, BP 578, Meknès, Morocco
E-mail(1): k.saffour@caramail.com
E-mail(2): olea@awamia.inra.org.ma

Abstract

In Morocco, food legumes cover annually 320 to 400 000 ha, of which 40 to 50% are faba beans. Orobanche infests more than 37% of faba bean cultivated areas. Highland areas, characterized by hard winters and fresh springs are currently slightly infested by this parasite. The absence of infestation could be due to an absence of orobanche inoculum or to the coolness of these zones. This study was carried out to determine the effect of temperature on the legumes infestation by orobanche in the highland areas. Trials were conducted in 1999/2000 and 2000/2001 crop seasons in pots artificially inoculated with Orobanche crenata Forsk. The pots were sown with faba bean or lentils every 15 days from October 1st to February 28th in two highland sites: Annoceur (1320 m of altitude) and Azrou (1500 m). Results showed that at Annoceur, broomrape emergence was observed on May 15th for the November 30th planting date. Insignificant emergence was observed until June 10th, for the sowings extended until February 15th, for both faba bean and lentils, without any effect on crop yield. In Azrou, broomrape emergence was observed between the 10th and 20th of April for the October and November sowings, when climate was still moderate. No more emergence was observed in the pots planted after November 30th. Nevertheless, some tubercles developed in the pots planted before the end of January without emergence and without any effect on crop yield. Delayed sowing because of the cool climate, could explain the absence of orobanche in the Moroccan highland regions which produce mainly faba bean for fresh pods use.