Biological and chemical control of Ectophoma multirostrata causing root-rot and seedling death of Celosia argentea in Karbala/Iraq

Abstract

This study was conducted in the College of the Agriculture/University of Karbala to control the fungus Ectophoma multirostrata that causes root rot of Celosia argentea by using Azotobacter chrocooccum, Salicylic acid and the chemical pesticide Beltanol. The pathogenic E. multirostrata was isolated for the first time in Iraq and showed a reduction in seed germination by 16.66% and 16.00%. The results showed that the bio-control bacteria A. chrocooccum, Salicylic acid and Beltanol effectively reduced the infection rate and severity of Celosia argentea root rot disease and increased the growth parameters. Among the treatments, Beltanol was the highest in reducing the infection rate and severity down to 0.00%, followed by the treatment of integration between A. chrocooccum and Salicylic acid to minimize infection and severity to 16.33% and 8.00%, compared to the infected untreated that showed 80%, 62.00% respectively. In addition, the A. chrocooccum and Salicylic acid integration improved plant growth, including shoot length, shoot and root dry weight to be 22.50 cm, 0.423 g and 0.133 g, compared to the untreated infected treatment that resulted in 5.00 cm, 0.090 g, and 0.003g, respectively. Keywords: Celosia argentea, Ectophoma multirostrata, Azotobacter chrocooccum, Root rot