A Date Palm Disease (Bunch Blight) Caused by Acremonium strictum (Cephalosporium) in Saudi Arabia

Abstract

Acrimonium strictum is reported as a new causal agent of a disease it names (bunch blight) in date palm (phoenix dactylefera) in Saudi Arabia. Symptoms and necrosis caused by A. strictum in susceptible cultivars showed small brown necrosis streak at midrib of fruit stalk in an early stage. There was an increase in number and size as the disease progresses; then extended to the bases of fruit strands due to death of bases and strands wilt, the infection of fruit strand caused drying the fruits and their fall. A. strictum attacks the bunches and move quickly inside and out the tissues causing brown necrosis and death of the tissues. A. strictum was isolated and pathogenicity tests were repeated more than once during two seasons and the identifications was caried several ways to confirm The confirmation of results by Biolog technique and DNA sequence were done. The proper temperature for infection was between 20-30 °C and the optimum 25 °C. When testing the susceptibility of varieties of infection, more varieties like Medjool, Saqae and Kholas were susceptible to infection and the most resistant to infection were Barhy and Khidri. The best results in the control of the fungus in vitro were due to use of Karpendazem followed Topsen M70, at the same time, the worst results were seen with the use of Abredion followed Karant (Cupper hydroxide).