Evaluation of the field efficiency of zinc oxide nanoparticles in resisting the fungus Rhizoctonia solani that causes black scurf disease in local potatoes

Abstract

The study aimed to isolate and purify the causative agent of black scurf disease on potato and to test the efficiency of zinc oxide (ZnO-PNs) in resisting the causative agent in the field. The most important symptoms were the presence of rot and ulcers in a brown color on the stems, branches, crown area and roots with the presence of the most important signs of infection, which is the appearance of sclerotia  on the tubers.The results of the pathological ability test showed that RU1 isolate is the most pathogenic and achieved the level of Strong virukent. As for the results of morphology and then molecular diagnosis by PCR technology, RU1 isolate represents the fungus Rhizoctonia solani, which is the cause of black scurf disease on potatoes. The isolate was recorded in the gene bank under Accession number ON055272.The results of the test treatments in the pots showed that all of them had an effect in reducing the percentage of infection and the severity of infection with the fungus (RU1), as the nano-zinc oxide treatment recorded the lowest percentage and severity of infection was (11 and 4.73) %, respectively, followed by the fungicide, which scored (22. 22 and 18.33) %, respectively, while it was zinc oxide, which was (33.33 and 19.03) %, respectively, compared with the control treatment (plant with RU1).The results of the study of growth parameters (plant height, fresh weight, dry weight and number of leaves) also showed that the nano zinc oxide treatment recorded a positive increase in growth parameters that amounted to (54, 24.33, 7.33 and 99.33)%, respectively, compared to the control treatment.In addition to the percentage of chlorophyll and phenol concentrations, high percentages were recorded in the nano zinc oxide treatment, which amounted to (1.03, 786.67) % respectively, while the regular zinc oxide treatment had good percentages that reached (0.45, 679) % respectively compared to the control treatment.