Chemical and plant-defense activator-based approaches to combat red rot caused by Colletotrichum falcatum in sugarcane

Muhammad Atiq¹, Ahmad Nawaz¹, Nasir Ahmed Rajput¹, Muhammad Jahanzaib Matloob¹ and Waqas Raza Arshad²

¹Department of Plant Pathology, Faculty of Agriculture, University of Agriculture, Faisalabad, Pakistan

²Sheikhoo Sugar Mills, Punjab, Pakistan

Red rot of sugarcane, caused by Colletotrichum falcatum, is the most destructive disease in many sugarcane-growing countries. Colletotrichum falcatum can reduce cane yield by up to 29% and cause sugar losses of up to 31%. Nine fungicides (Shincar, Nativo, Amister Top, Topsin M, Ridomil Gold, Allite, Score, Antracol and Rovral) were evaluated against C. falcatum under in vitro conditions, three plant defense activators (salicylic acid+KH₂PO₄, salicylic acid, and KH₂PO₄) were evaluated in a greenhouse, and nine chemicals (carbendazim spray, salicylic acid spray, carbendazim +salicylic acid+KH₂PO₄ flood, KH₂PO₄ spray, carbendazim flood, salicylic acid flood, Coragen (chlorantraniliprole) flood and micro-nutrients spray) were evaluated in a field trial. Shincar fungicide was the most effective in limiting fungal growth (4.13 mm), followed by Nativo (15.62 mm), Amister Top (26.19 mm), Topsin M (37.64 mm), Ridomil Gold (45.19 mm), Allite (52.49 mm), Score (59.44 mm), Antracol (67.71 mm), and Rovral (76.81 mm) as compared to the control. In the greenhouse, salicylic acid+ KH₂PO₄ showed the lowest disease incidence (10.40), followed by salicylic acid spray (13.92) and KH₂PO₄ spray (20.25) compared to the control. In the field, carbendazim spray showed the lowest disease incidence (10.10%), followed by salicylic acid spray (21.60%), carbendazim + salicylic acid + KH₂PO₄ flood (32.17%), KH₂PO₄ spray (43.62%), carbendazim flood (51.19%), salicylic acid flood (58.49%), Coragen (chlorantraniliprole) flood (74.29%) and micro-nutrients spray (82.85%) compared to the control.