المكافحة الأحيائية لمسبب مرض التبقع الكلادوسبوري في نبات الباذنجان المتسبب عن الفطر Cladosporium cladosporioides

Abstract EN

The aim of this study was to control eggplant Cladosporium disease caused by the fungus Cladosporium cladosporioides using the biological control fungi Aspergillus niger, Trichoderma harzianum and T.

koningii.

The effect of these agents was tested in vitro.

Three isolates of C.

cladosporioides were obtained from various eggplant-growing regions in Basrah governorate.

When testing the pathogenic capacity of the three isolates, isolate 1 from Shatt al-Arab area was found the most severe, with 68.7% severity of infection, and accordingly this isolate was used for further testing.

Bio-fungicide filtrate was tested for its ability to reduce the growth of pathogenic fungi in PDA medium.

All filtrates concentrations tested affected the fungal growth of pathogenic fungi with a rate of inhibition between 29.61 and 40.69%.

In addition, spores concentrations of the bio-control agents (10, 20 and 30 ml filtrate/L) reduced the sporulation of the pathogenic fungus C.

cladosporioides.

The average number of spores per one ml of pathogenic fungus reached 22.73, 19.96 and 16.95 × 103, respectively, compared with 40.11×103 for the control treatment.

For comparison purposes, carbendazim fungicide was also tested to inhibit the pathogenic fungus in PDA medium, and the rate of inhibition of C.

cladosporioides obtained was 33.95, 68.26, 82.99 and 100%, respectively, for concentrations 25, 50, 75 and 100 ppm.

Filtrates of A.

niger, T.

harzianum and T.

koningii (20 and 30 ml filtrate/L) were found to reduce the severity of C.

cladosporioides infection on eggplant plant by 33.65, 30.12 and 28.42%, for the three fungi, respectively, compared to 66.86% for the control treatment.

The fresh and dry weight of eggplants treated with bio-fungicides was increased.

Eggplants treated with bio-fungicides showed an increase in peroxidase activity compared with the control treatment.