الكشف عن الفطريات المرافقة عن طريق بذور و نباتات الدنان و تقويم مقدرتها الإمراضيه

الملخص EN

This experiment was conducted to detect the fungi associated with seeds and shoots of Barnyardgrass and to evaluate the efficacy of the isolated fungi on biocontrol of barnyardgrass under glass house condition.

Results of isolation and identification showed the existence of 26 species of fungi associated with barnyardgrass seeds which were isolated from five samples collected from four governorates, Theykar, Messan, Al-Najiff and Al-Kadessia.

The percentage of frequency of these fungi ranged 0.0 % - 65.0 %, also 8 species of fungi were isolated from the foliage of one sample of Barnyardgrass collected from Abu-Ghraib location, Baghdad governorate with 5 % - 35 % percentage of frequency.

The isolation and identification of these fungi regard the first record of these fungi on Barnyardgrass in Iraq.

Alternaria alternata (Fries) Keissler was the most frequently fungus found on seeds and shoots of Barnyardgrass, it was isolated from all the tested samples with 7.75 % - 65.0 % percentage of existence, while the percentage of frequency in the foliage sample was 35 %.

Results of spray of Barnyardgrass seedlings 21 days old with spore suspension of eight pathogenic fungal isolates showed disease severity ranged from 26 % for the Ulocladium atrum (UA5) isolate to 62 % for Curvularia tuberculata (CT4) isolate , while all the isolates revealed significant reduction in foliage fresh and dry weight of Barnyardgrass seedlings.

Results of soil treatments with spore suspension of eight pathogenic fungal isolates showed significant effect ( p=0.05) in percentage of seed germination disease severity and fresh and dry weight for the shoots and roots compared with the control treatment , Cylindrocarpon didymium (CD3) isolate showed highest effect it gave 20.0 % , 73.3 % , 2.1 gm / plant , 1.40 % gm / plant , 2.50 gm / plant and 1.00 gm /plant respectively