Mikania management in coffee plantation with pre- and post-emergent herbicide combinations

Potential yield of coffee in Northeast India is adversely affected by Mikania micrantha Kunth infestations. The study, conducted at Diphu, Assam during 2016 and 2017, was aimed to managing Mikania micrantha in coffee plantations through hastening the seed germination by soil application of gibberellic acid and killing the germinated seedlings by pre- and post-emergent herbicide application. Gibberellic acid 500 ppm significantly increased the Mikania micrantha seed germination, than 250 ppm, and control without any effect on the growth and yield of coffee. Oxyfluorfen 0.29 kg/ha followed by (fb) glyphosate 0.99 kg/ha + 2,4-D 0.73 kg/ha and oxyfluorfen 0.29 kg/ha fb glyphosate (0.99 kg/ha) resulted in successful management of M. micrantha and significantly increased the vegetative growth and yield of coffee as compared to the weedy check. Highest net return and B:C ratio during 2016-17 and 2017-18 were observed with oxyfluorfen 0.29 kg/ha fb glyphosate 0.99 kg/ha + 2,4-D 0.73 kg/ha. Next best treatment was oxyfluorfen 0.29 kg/ha fb glyphosate 0.99 kg/ha. At present, 2,4-D usage is not recommended for coffee. Therefore, oxyfluorfen 0.29 kg/ha fb glyphosate 0.99 kg/ha can be recommended for control of Mikania micrantha in coffee plantations.