DefinePK

Abstract

Onion ( Allium cepa L.) is a major vegetable crop widely cultivated and consumed globally, including in Pakistan.  A systematic survey was conducted during 2022-23 in Sindh Province to record the incidence of blue mold disease. Diseased samples showing typical blue mold symptoms were collected for further analysis, and pathogenicity tests were performed to confirm the causal agent. For the in vitro experiment, different plant extracts, Brassica juncea , Capsicum annuum , Coriandrum sativum , Mentha spicata , and Zingiber officinale , were evaluated at three concentrations (4%, 8%, and 12%) against the mycelial colony growth of the pathogen. The in vivo trial was carried out using the most effective plant extracts to assess their efficacy in reducing rot severity (%) on onion bulbs. Among all surveyed districts, the highest disease incidence was recorded in Tando Allah Yar. The in vitro experiment revealed that C. sativum , followed by Z. officinale at 12% concentration, was significantly effective against the test fungus, showing mean mycelial growth inhibition of 76.29% and 71.88%, respectively. M. spicata also showed moderate inhibition (54.81%) at the same concentration, whereas C. annuum and B. juncea exhibited the least inhibitory effects compared to the others. The in vivo experiment demonstrated that C. sativum , followed by Z. officinale , was the most effective in reducing rot severity on onion bulbs, recording 31.00% and 44.33% severity, respectively, compared to 86.67% in the untreated control. It was concluded that C. sativum and Z. officinale extracts are effective and eco-friendly options for managing blue mold rot in onion.