Invasive Species Compendium

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Abstract

First report of shoot blight caused by Neoscytalidium dimidiatum on citrus in Jordan.

Abstract

In October 2017, a new disease was reported to the National Agricultural Research Center by a citrus farmer in Northern Shoneh, Irbid, Jordan. Symptoms were noticed on different citrus trees grafted on 2 rootstocks (sour orange and Citrus volkameriana). The trees were clementine (C. clementina), grapefruit (C. paradisi) and pummelo (C. maxima). A total of 300 trees were affected and were removed (2 of 22 ha) to reduce the inoculum. Affected trees suffered from dryness and death of branches (shoot dieback), discoloration of the vascular tissue and sometimes gummosis. A primary survey showed that approximately 10% of citrus trees in that area exhibited symptoms. Samples from different infected citrus types showing shoot dieback were collected. The causal pathogen was isolated and identified as Neoscytalidium dimidiatum based on morphological, molecular and pathogenicity analyses. DNA sequences were deposited in GenBank (ITS, MK530327; BT, MK830061). This is thought to be the first record of a disease caused by N. dimidiatum on citrus in Jordan.