Investigation and Detection of the dieback on Juniperus Phoenicea trees in al-Jabal Al-Akhdar

The dieback on the Juniperus Phoenicea in Al-Jabal Al-Akhdar north east of Libya was reported without proof of disease causative in 2014 and 2016. This investigation carried out to reveal the cause of the disease. The spatial statistics method was used to determine the relationship between disease and other environmental variables (Land surface temperature, elevation, slope, rainfall, and the distance from coast). Random sampling of the trees branches were taken from most of the forests of the region. The study indicated that the isolated microorganism of the dieback on the Phoenician Juniper recognized a fungal infection of Diplodia Africana by analyzing culture, morphological, and PCR of genomic TSI and 1-alpha gene. The result shows that the most infected sit is that the closer to the coast which was confirmed with strong negative correlation (-0.583), furthermore the relation with the elevation showed same direction with (-0.604), while the LST presented positive correlations (0.367) thus confirming the significant effect of temperature in increasing these diseases.