Control of Pestalotiopsis leaf spot of palms by fungicides, plant hormones and biological agents

This study investigates fungal leaf spots of palm, an ever-present threat to the nursery and floriculture industry. Fungicides, plant hormones and biological agents were used to consider their implications for Pestalotiopsis leaf spot disease management in palms. A survey of different locations in Pakistan's Kasur and Faisalabad districts was conducted, collecting data on disease incidence of debilitating leaf spot disease in Roystonea regia (royal palm) and Ravenea rivularis (ravenea palm). Pathogenicity tests were performed on healthy seedlings using Pestalotiopsis sp. The results indicate that the fungicide Flumax with 86.11% growth inhibition of pathogenic fungus, and biological agent Trichoderma asperellum with 76% growth inhibition have a significant impact in suppressing pathogen growth. Compared with the fungicide or SA application alone, the combined application of SA with 50% less fungicide (Flumax) in an integrated program significantly reduced disease severity to 5.9% and 6.2%, in royal and ravenea palms respectively. Our findings highlighted that integrated disease management (IDM) could be crucial in addressing Pestalotiopsis leaf spot disease. Adapting to IDM can improve the aesthetic value and profitability of palms by allowing a reduction in fungicide use while maintaining effective control of the disease.