فاعلية المكافحة المتكاملة في السيطرة على بعض مسببات مرض تعفن جذور نبات عرف الديك Celosia argentea

The effectiveness of integrated control in controlling some pathogens of root rot disease on Celosia argentea

This study was conducted at the College of Agriculture – University of Karbala with the aim of isolating and diagnosing the fungi causing root rot of Celosia argentea in a number of nurseries in the governorates of Karbala and Babylon. In addition the most pathogenic fungi isolated in this study will be tested to determine their host range and testing the antagonistic ability of a number of biological factors, chemical pesticides, salicylic acid and chitosan in combating the most pathogenic fungi that cause rotting of the roots of the C. argentea in the laboratory and under the conditions of the plastic house in the plastic pots.
The results of the isolation showed that the morphological diagnosis obtained 20 isolates belonging to the fungus Rhizoctonia spp. and 22 isolates of Fusarium spp. And 3 isolates of the fungus Ectophoma sp. The results of pathogenicity showed that isolates R16 and F3 significantly reduced the percentage of germination of red radish seeds to 0.00%, as well as their complete inhibition of the germination of C. argentea seeds compared to the comparison treatment in which the percentage of germination reached 100% for both types of seeds.
The results of the molecular diagnosis of isolates R16, F3, E2 confirmed by analyzing the sequences of the nitrogenous bases of the doubling DNA products by polymerase chain reaction of the selected genetic markers and comparing them with the global strains and isolates using the BLAST program (Basic Local Alignment Search Tool). These isolates were Rhizoctonia solani (R16). Ectophoma multirostrata (E2), Fusarium solani (F3) whose sequences of six genetic markers important in mycobacterial diagnosis included internal transcribed spacer (ITS), translation elongation factor (TEF-1α), RNA polymerase I (RPB 1) and RNA polymerase II (RPB 2), and beta-tubulin 1 (β-tubulin), as well as mitochondrial small-subunit ribosomal RNA, in addition to identifying its complete genome for the first time in Iraq. Within the NCBI-genome database under the code JAMJFY000000000.1.
The results of the family range test of fungal isolates R16, F3, E2 showed that they have a wide family range represented in the inhibition of germination of cucumber, ruqyi, watermelon, eggplant, hot pepper, tomato and Ayn al-Bazoun seeds in different proportions.The laboratory results of the antagonistic ability of the biological agent koningiopsis Trichoderma showed its high inhibitory ability which reached 100%, 88.88% and 94.40% against the fungi R. solani (R16), F. solani (F3) and E.multirostrata (E2) respectively. Also, Azotobacter chroococcum achieved an inhibition rate of 100% against all tested fungi.
The chemical pesticides Beltanol, Basten and Metehazole achieved 100% inhibition rates against R. fungi. solani (R16), F. solani (F3) and E. multirostrata (Ec2) tested with all the concentrations used, while the percentage of inhibition of Verox biocidal was 16.66%, 72.22%, 77.77%, respectively when using the recommended concentration compared to the comparison treatment. The inhibition percentage was 0.00% for all fungi.
The results of the chitosan efficacy test at concentrations 0.5, 1, and 2% showed that the concentration was significantly superior to 2% (P>0.05) by achieving the percentage of inhibition of the fungi R. solani (R16), F. solani (F3) and E.multirostrata (E2) tested amounted to 66.6%, 88.8% and 75.5%, respectively, compared to the control treatment, which amounted to 0.00%, while the results showed the use of salicylic acid at concentrations of 0.5, 1, and 1.5 g/L, the concentration of 1.5 g/L was significantly (P > 0.05) superior in its inhibition of pathogenic fungi. Above, the inhibition percentage was 72.2%, 88.8% and 72.2%, respectively.
The treatment of the chemical pesticide Beltanol was significantly superior to the other treatments in reducing the percentage of infection, which reached 8.0%, 2.1%, and 6.0%, and the percentage of infection severity to 2.0%, 0.0% and 0.0%, respectively, for the fungi R. solani, F. solani and E . multirostrata followed by the treatment of interaction between the biological factors Tr + Az, which led to a reduction in the incidence of pathogenic fungi to 20%, 11% and 18%, respectively, and the severity of infection to 9%, 15% and 6.66% compared to treatments of pathogenic fungi alone, which reached rates of infection. 100%, 100% and 100%, respectively, and the infection severity percentages were 87%, 80% and 62%, while in the right comparison treatment it amounted to 0.0%, and the percentage of infection in the other treatments ranged from 15.33%-67.00%, and the infection severity rates were 7.00% – 49.00%
The treatment of interaction between the biological factors Tr+Az and the plant pathogens was superior in increasing the growth parameters compared to the treatments of the pathogenic fungi alone. 0.131 g, respectively, followed with a significant difference by the treatment of 3 Tr + Az + Fu, in which the growth parameters reached 22.33 cm, 10.03 g, 2.40 g, 0.996 g, and 0.132 g, respectively. In the Tr + Az + Rh16 treatment, the growth parameters reached 20.00 cm and 9. 30 g, 2.03 g, 0.775 g, and 0.084 g, respectively, and this treatment did not differ from the interaction between Tr+Sal and Az+Sal in the presence of pathogenic fungi.