الفهرس | Only 14 pages are availabe for public view |
Abstract An isolate of Alternaria sp. was studied as a potential biocontrol agent for waterhyacinth. The aspects studied included: taxonomic identification , host range, sporulation, efficacy of spore vs. mycelial inoculum, phytotoxin production, optimum conditions for inducing virulence , and bioherbicide formulations. Alternaria cassiae, a bioherbicide agent for siklepod (Cassiae obtusif o lia) , was used as an analogue in certain experiments. our ultimate goal is to develop a bioherbicide to control waterhyacinth in waterways in Egypt; this study paved the way toward this goal. Among the three Egyptian isolates of Alternaria, isolate no. 5 was the most virulent on water-hyacinth. Based o n spore measurements, growth characteristics, and pigmentation, and in comparison with an authentic culture of A. eichhorniae, the Egypt an isolates no. 5 and no. 3 were identified a s A. eichhorniae Nag Raj and Ponnappa and isolate no. 6 as A. alternata (Fr.) Keissler. A. eichhorniae 5 was host-specific to waterhyacinth plants. Among the ninety-six pl9nt species and cultivars tested, all of which are economically important in Egypt, only waterhyacinth was found t o be susceptible to this isolate. |