Figures (2)  Tables (4)

    • Figure 1. 

      Morphology of A. alternata on (PDA). (a) Different shape and size of conidia. (b) Conidia in a chain with four conidia. (c) Conidia pattern on (PDA) surface. (d) Conidiophore development.

    • Figure 2. 

      Date palm diseases caused by A. alternata. (a) Inflorescence rot. (b) Fruit rot. (c) Leaf spot. (d) Shoot-hole.

    • No. Alternaria species Date palm portions
      Inflo Fruits Leaves Roots Insects &
      mites
      1 Alternaria alternata + + + + +
      2 A. arborescens − − + − −
      3 A. burnsii − − + − −
      4 A. chlamydospra − − + − −
      5 A. consortialis − − + − −
      6 A. dianthicola − − + − +
      7 A. longipes − − + − −
      8 A. plurispora − − + − −
      9 A. radicina − − + − −
      10 A. raphanin − − + − −
      11 A. tenuissima − − + − −
      12 A. tomato − − + − −
      +, present; −, not present.

      Table 1. 

      Presence of Alternaria species in date palm orchards across various regions.

    • Biological classification Name
      Kingdom Fungi
      Subkingdom Eumycota
      Phylum Imperfect fungi
      Class Hypomycetes
      Order Moniliales
      Family Dematiaceae
      Genus Alternaria
      Species Alternata

      Table 2. 

      Scientific classification of A. alternata.

    • Fungi species Host plant Disease Toxin Ref.
      Alternaria alternata Spotted knapweed Black leaf blight of
      spotted knapweed      		 Maculosin- toxin Stierle et al.[37]
      Alternaria alternata Sunflower Leaf disease of sunflower AS-toxin Liakopoulou-Kyriakides et al.[38]
      Alternaria alternata f.sp. citri Rough lemon Leaf spots of rough lemon ACR-toxin Masunaka et al.[39]
      Alternaria alternata f.sp. fragariae Strawberry Black spot of strawberry AF-toxin Maekawa et al.[40]
      Alternaria alternata f.sp. kikuchiana Japanese pear Black spot of Japanese pear AK-toxin Tanaka et al.[41]
      Alternaria alternata f.sp. lycopersici Tomato Stem canker of tomato AAL-toxin Bottini & Gilchrist[42]
      Alternaria alternata f.sp. mali Apple Alternaria blotch of apple AM-toxin Johnson et al.[43]
      Alternaria alternata f.sp. tangerine Tangerine Alternaria brown spot ACT-toxin Kohmoto et al.[44]

      Table 3. 

      Host-specific toxins produced by A. alternata.

    • Fruit stage growth of the date palm Cultivar
      Tamar Rutab Khalal Kimri
      Control Unwounded Wounded Control Unwounded Wounded Control Unwounded Wounded Control Unwounded Wounded
      0 0 0 0 0 30% 0 0 63% 0 0 51% Sayer
      0 0 0 0 0 33% 0 0 50% 0 0 55% Barhi
      0 0 0 0 0 20% 0 0 22% 0 0 32% Zahidi
      0 0 0 0 0 11% 0 0 44% 0 0 21% Hallawi

      Table 4. 

      Infection percentage of different varieties of dates and their growth stages with the fungus A. alternate[50].