Vol. 9, Issue 10 (2020)

Author(s):
Pinky Chanu Laiphrakpam, RK Imotomba Singh, Suchitra Chanu Heikrujam and Kripalini Ningombam

Abstract:
Chilli (Capsicum annuum L.) is one of the major vegetables growing in Manipur. Bacterial wilt caused by Ralstonia solanacearum is responsible for the reduction of its yield production. Thirty chilli plants which show the bacterial wilt symptoms were isolated. The organism produced small milky white fluidal colonies on Sucrose Peptone Agar after incubated at 28±1⁰C for 48 hours. The organism was 0.5 x 1.5 µm in size, motile, rod in shape. Evaluation of antibiotics and bactericides resulted that streptocycline gave maximum inhibition zone 25.6 mm in diameter followed by ciprofloxacin, tetracycline, cephalexin, streptomycin and bacterinashak at 100 ppm. Tetracycline showed maximum inhibition zone of 27.2 mm in diameter followed by ciprofloxacin, streptomycin, bacterinashak, cephalexin and streptocycline at 200 ppm. At 300 ppm ciprofloxacin showed maximum inhibition zone of 33.4 mm in diamter followed by tetracycline, bacterinashak, streptomycin, cephalexin and streptocycline. However, erythromycin and amoxicillin were found to be non effective against bacterial wilt pathogen. The result of the paper disc method indicated that there is no significant difference between ciprofloxacin and tetracycline at all level of concentration which indicates these two antibiotics are equally effective. But ciprofloxacin cannot be recommended for plant disease management. According to the result of turbidimetric method, all the antibiotics and bactericides were unable to inhibit the growth of bacterial wilt pathogen. However, least density of turbidity have been recorded in bacterinashak treated inoculums solution followed by ciprofloxacin treated inoculums. The result of statistical analysis indicated that there is no significance difference between ciprofloxacin and bacterinashak treatments.