La fusariose vasculaire du palmier dattier (Bayoud): méthodes de lutte

Comunicación presentada en la Jornada Multidisciplinar sobre las Bases Ecológicas y Culturales del Oasis de Figuig (Marruecos), Oujda, Marruecos, 24 de febrero de 2012Proyecto de Cooperación Internacional al Desarrollo AP/301-34-2010 de AECID

Global Journal of Plant Ecophysiology Arbuscular Mycorrhizal Fungi Effect in the Protection of date Palm (Phoenix dactylifera L.) against the Pathogenic agent Fusarium oxysporum f.sp. albedinis ( Bayoud disease)

Objective: The aim of the present work was to study the effect of native arbuscular mycorrhizal fungi, coming from the oasis of Figuig in the South-Est of Morocco, in the protection of date palm (Phoenix dactylifera L.) against Bayoud disease. Results: Treatment with AMF reduced disease severity; the presence of the pathogenic agent Fusarium oxysporum f.sp. albedinis (Foa) caused a fall of biomass with a death rate of 100% whereas the presence of mycorhizae caused a drop in this rate mortality to 30%. In addition, mycorrhizal fungi stimulate significantly shoot height and biomass and increase the number of leaves per plant. Conclusion: In conclusion, the mycorhization could constitute an important biological means making it possible to fight against the plant external aggressions

Corresponding Author Effect of Nitrogen Sources on the Composting of Date Palm (Phoenix Dactylifera) By-products Infected by Fusarium Oxysporum f.sp. Albedinis

ABSTRACT The by-products of palm date (Phoenix dactylifera) contaminated by Fusarium oxysporum f.sp. albedinis (Fusarium) were composted with different rates of bovine manure, urea or ammonium nitrogen. Water was added to maintain optimum humidity at 60-70%. During the process of composting and whatever the ratio of the manure or nitrogen in the piles, the pH remained stable and relatively alkaline at values ranging from 8.2 to 8.7. By contrast, electrical conductivity decreased from 25 to 30%. The evolution of the internal temperatures in the piles depended on the volume of the manure added to the mixture, but was characterized by a mesophilic phase showing a fast increase in temperature, then a thermophilic phase, with high temperatures ranging from 50 to 70°C in the piles rich in bovine manure. However, internal temperatures remained unchanged in urea-or ammonium-containing piles. In the piles containing bovine manure, Fusarium was completely eliminated during the thermophilic phase. The rate of its destruction depended on the ratio of the manure introduced into the piles. Indeed, when the ratio increased, the elimination of Fusarium is fast. In the presence of ammonium nitrogen, proliferation of pathogenic agent increase to 62%. Experiments on rachis pieces of the palms infected by Fusarium, show that their incubation for 6h at 70°C or for 12h at 60°C destroy completely the pathogenic fungus. The C/N ratio of the date palm by-products is very high (115.4), owing to the fact that they are very rich in organic matter (90%) and very low in nitrogen (0.39%). The addition of bovine manure brought C/N ratios in the piles to values ranging from 35 to 60. During the composting process, this ratio decrease constantly from 35 to 46% of its initial value after 75 days of incubation. On the contrary, in the piles containing urea and ammonium nitrogen, C/N ratio increase by 87 and 60%, respectively