Red palm weevil (RPW) is a dangerous pest that infects the date palm tree and makes
tunnels in the tree’s trunk. RPW infection is followed by secondary invaders of microorganisms
that cause degradation of the trunk tissues leading to toppling the crown and death of the tree in a
short time. This study showed that Fusarium oxysporum Schlecht. was the common fungal species
isolated from the root and trunk tissues of the date trees infested with RPW, which recorded 100% of
frequency. Pathogenicity of 4 isolates of F. oxysporum was confirmed on date palm seeds and seedlings.
The results confirmed that all isolates involved in rot of the germinated seeds (40–100% incidence),
root rot, and death of palm seedlings (20–100%) under artificial infection as well as degradation of
date palm petioles. Application of 20 L/palm of systemic fungicide (Topsin) at 1% as foliar and soil
drench of date palm for successive three times successfully reduced development of the deterioration
and suppressed the growth of F. oxysporum. Interestingly this fungicide did not suppress the growth
of Trichoderma viride Pers. So, our results recommend this fungicide to suppress the pathological
and degradable activities of F. oxysporum during the integrated pest management of RPW on date
palm trees.