EVALUATING THE EFFICIENCY OF MEDIA AND SOME OILS ON THE SPORULATION OF FUNGI ISOLATED FROM COGONGRASS AND THE ABILITY OF DRECHSLERA STATE OF COCHLIOBOLUS BICOLAR TO INFECT COGONGRASS.

Abstract

This study was carried out to evaluate the efficiency of different media and their formula for increasing the sporulation of fungi isolated from Imperata cylindrica and improve the activity of Drechslera state of Cochliobolus bicolar with different oils. Results revealed that the culture medium of leaves and stems of Cogongrass was the best for fungus sporulation, that gave an average of 29.22 x 106 spore/10 gm of medium followed by crushed Rhizomes 27.80 x 106 spore/10 gm. The wheat bran with kaoline medium gave the lowest number of spore 8.6 x 106 spore/10 gm. Also the efficacy test for four different formula to maintain pathogenic fungi viability on Cogon grass has been found that crushed corn ear and wheat bran formula gave the higher capacity to preserve the viability and infectivity of pathogenic fungi, with mean number of colony forming units in the day zero of storage 108.90 x 106 CFU/gm, compared with102.2 x 106 and 94.31 x 106 after 3 and 6 month of storage respectively. The results of the evaluation of effect of different oils concentrations on Drechslera state of Cochliobolus bicolar growth revealed the superiority of corn oil at 2% and Dabana oil at 0.25% treatments in the preservation of fungus growth, Both treatments gavae radial growth of 9cm after 7days of incubation compared with 9 cm in the control treatment. In the laboratory study to evaluate the efficacy of some oils to maintain moisture , results showed the superiority of corn oil 2%, it maintain the water for 9 days, while other oils (Helb oil 0.25%, Dabana oil 0.25%, glycerin oil 1% and cestrol oil 0.25%) kepte the water for 8 days compared with 7 days in the control treatment. Results of evaluation the efficiency of some oils to increase the activity of the bio-control agents to increase the infection of Cogon grass under glass house conditions showed the superiority of corn oil 2% treatment which caused 71.87% disease severity followed by Helb oil 0.25% 58.12%.