Biocontrol Capacity of the Soil Fungus Trichoderma harzianum against Fusarim oxysporum f. sp. albedinis, a Causal Agent of Fusarium Wilt (Bayoud) Disease of Date Palm (Phoenix dactylifera L.)

Abstract

Backgraound: This study has the objective to study antifungal effect of the antagonistic fungus of soil named Trichoderma harzianum on mycelial growth of twenty isolates of Fusarium oxysporum f. sp. albedinis (Foa), agent of the bayoud disease on the date palm, originated from south western region of Algeria. Methods: Twenty Foa isolates obtained from isolation of the spines carrying the typical symptoms of Bayoud disease were used. The strain of T. harzianum was isolated from rhizosphere soils of the date palm trees. The in vitro test affected by two tests of confrontation, direct which is dual confrontation and indirect confrontation by volatiles substances, on mycelial growth. Result: A statistical analysis showed a significant difference (P less than 0.05), of Foa isolates reaction against the antagonistic fungus T. harzianumin the test realized.The results of in vitro test showed a significant effect (P less than 0.05), on mycelial growth in both tests used. The inhibition rate (IR) of mycelial growth of Foa by T. harzianum varies between 28.42 and 59.12%, with 12 Foa isolates showed IR, more than 50% in the direct test and between 3.3 and 56% with just three (3) isolates have IR more than 50% in the indirect test by volatile substances. Based on these encorageous results, we can apply of this antagonistic fungus to protect our groves contaminated by Bayoud disease and also contain this susceptible commercial variety.