Occurrence of Black Scurf Disease of Potato in Multan (Punjab) Alongwith Its in vitro Chemical and Biotic Elicitor Mediated Management

Abstract

Black scurf disease of potato, caused by fungus Rhizoctonia solani, is the most common and one of the oldest diseases of potato affecting stem and stolons. In recent years, the disease is reportedly present in the fields of potato in Pakistan especially in Punjab. Survey of different locations viz. Narangaabad, Band Bosan, Kaian Pur, Kotla Abdul-Fateh and Dhillun was conducted to assess the prevalence of disease in Multan region. Maximum disease incidence and severity of 95.00% and 3.1 rating, was recorded in Kotla Abdul-Fateh respectively. Sclerotial pieces showing characteristic symptoms of black scurf were detached from tuber surface and the fungus was isolated on potato dextrose agar medium. For in-vitro chemical and biotic elicitor testing, three different fungicides viz., Monceren, Topsin-M, and Triton were evaluated using poisoned food technique and antagonistic effect of two accessions of Triochoderma spp . viz. Trichoderma harzianum and Trichoderma viridae was determined against the sensitivity of fungus. Triton was found to be superior at all concentrations in inhibiting the radial mycelial growth of the fungus followed by Topsin-M and Monceren. Satisfactory results were obtained by the antagonistic effect of Trichoderma harzinaum and Trichoderma viridae with 70.00% and 66.00% respectively under in-vitro conditions. Although the fungicide chemistries exclusively control the fungus yet the evaluation of bioagents also remained prolific towards antagonism against Rhizoctonia solani . These investigations provide fresh information on the current status of black scurf disease of potato in fields of Multan and regarding the biochemical management against Rhizoctonia solani under in-vitro conditions and serve as a guide for the future prospects against this holistic disease.