Effect of Some Control Treatments on Reducing Root Rot Disease of Cowpea (Vigna unguiculata L.) and Inducing Physiological and Defense Responses under Field Conditions

• Weaam Hamed Al-Samarrai¹*, Khalaf Atiyah Mohammed¹

  Author

This study aimed to evaluate the efficiency of some biological and chemical control treatments and biostimulants in reducing cowpea root rot disease and improving the physiological and defense responses, as well as yield components, under field conditions. The field experiment was conducted at the field of the Department of Plant Protection, College of Agriculture, University of Tikrit, during the 2025 growing season, using a randomized complete block design (RCBD) with three replications. The study included two cowpea cultivars: the local cultivar and Cowpeas Ramshorn. The treatments included infected control, fungicide, seaweed extract, amino acids, Pseudomonas fluorescens, dual combinations among these factors, the quadruple combination, and healthy control. The results showed significant differences among the different treatments. The infected control treatment recorded the highest disease incidence and disease severity, reaching 87.50 and 66.67%, respectively, whereas the quadruple combination treatment recorded the lowest disease incidence and disease severity, reaching 25.00 and 9.38%, respectively. The different treatments also improved the physiological and vegetative growth traits of the plants, as the quadruple combination treatment recorded high values for chlorophyll content, leaf area, and plant height, reaching 56.55 SPAD, 55.00 cm², and 91.67 cm, respectively. The results also showed the superiority of the quadruple combination treatment in yield components, as it recorded the highest number of seeds per pod, reaching 11.17 seeds, the highest 100-seed weight, reaching 26.17 g, and the highest yield of three harvests, reaching 233.33 g. Regarding defense enzymes, the amino acid treatment recorded the highest polyphenol oxidase activity, reaching 12.66 U ml⁻¹, while the fungicide treatment and the seaweed extract + amino acids treatment recorded the highest peroxidase activity, reaching 10.88 and 10.83 U ml⁻¹, respectively. The results indicate that combining control methods with biostimulants was more efficient than individual treatments in reducing cowpea root rot disease and improving the physiological, defense, and productive performance of the plants under field conditions.

• pdf