Inner leaves blight of tissue culture date-palm (barhee variety)‎ caused by fusarium solani after acclimatization stage and its control

الملخص EN

During March-May 2008, new disease symptoms were observed in tissue culture date palm (Barhee cv.) in some Egyptian agricultural tissue culture laboratories after acclimatization stage.

The first symptoms appeared as irregular dark brown spots with a yellow hallow concentrated on the top with a yellow hallow of young unfolded leaves emerging from the bud.

Several spots may coalesce to cover large portion on the inner leaves and finally leaves were dead, and turned brown in color which give a blight appearance.

Sometimes, spots were not only present in the upper portion of the inner leaves but also it would be down ward to the core direction of the crown tissue.

Isolation trail from the unfolded leaves and crown yielded Fusarium solani, no pathogenic fungi were isolated from roots.

Pathogenicity tests indicated that the ability of the pathogen to attack the inner leaves and crown tissues causing disease symptoms as well as its ability to attack the old leaves causing brown blotches on both rachis and leaflets.

Histopathologically investigation of the basal parts of inner leaves (the core tissues) sections taken from artificially infected tissues with F.

solani indicated that the fungal hyphae were able to invade different tissues of basal parts of inner leaves with presence of necrotic parenchyma cells and xylem vessels blocked with tylosis and gummosis.