Use of Herbicides for Control of Banana Bacterial Wilt in Uganda

The potential of herbicides for destroying banana plants infected with bacterial wilt has been evaluated. Experiments were conducted on station at Kawanda Agricultural Research Institute (KARI) and on-farm at Nekoyedde and Kimenyedde, in Mukono district. Two systemic herbicides, Glyphosate and 2, 4-D were evaluated for their effectiveness in destroying infected banana plants. Selected plants were injected with 20ml of herbicide in water at the rate of 1:20 administered in a perforated hole at the collar base of the pseudostem close to the corm using a sharp pencil-size metallic rod. All plants injected with 2,4-D herbicide snapped and died within 30-60 days while plants injected with glyphosate wilted and dried up within 90-120 days. Both herbicides were able to kill at least 85% of the plants. Plant destruction depended on herbicide dose, mat size and nature of suckering. Re-suckering rates between the two herbicides did not significantly differ. The mean re-suckering on farmer's fields was 1.5% for glyphosate and 7.2% for 2,4-D compared to 15.2% and 11.3% on the station. Herbicides were able to destroy plants within radius of 16.8 ± 1.76 cm from the injected plant per mat. Higher doses killed faster and better but it was not clear why very high doses caused high re-suckering. It was therefore concluded that although 2,4-D herbicide destroyed banana mats faster than Glyphosate, in the long run however, the efficiencies of kill between the two herbicides do not differ significantly. Both herbicides showed great potential for use as an option for removal or destruction of diseased plants. However, considering environmental safety issues, Glyphosate is recommended for farmer use in Uganda.