Abstract:
Bitter gourd (Momordica charantia) is one of the famous highly medicinal value vegetable crops
in the Sri Lanka. The bacterial wilt disease caused by Ralstonia solanacearum is known with
negative effect in crop production. The studies related to screening of resistant varieties for this
disease is less known. Therefore, this study was aimed to assess the resistance levels of various
bitter gourd breeding lines against bacterial wilt disease and to develop an effective eco-friendly
disease control method. The experimental design employed in this study follows Complete
Randomize Design. Pathogen was isolated from diseased plant and pathogenicity test was done.
Healthy bitter gourd plants were inoculated with bacterial suspension, and disease incidence was
assessed within 14 days after inoculation. Data analysis was done using the SAS 9.4 version. Data
were analyzed by Analysis of Variance and means were compared by Duncan's Multiple Range
Test. The disease incident scale was considered according to the protocol of the Asian Vegetable
Research and Development Centre. Different bitter gourd lines were screened for their
susceptibility or resistance to bacterial wilt, resulting in the categorization of Neerogi (7%) and
Thinnaveli white (9%) as resistant, MC43 as moderately resistant (18%), MG (25%) as
moderately susceptible, Matale green (70%), Kalu karavila (65%), and Krishna (50%) as
susceptible. In addition to this, five soil amendments were used for the effective control measures
(paddy husk biochar (1 and 2 kg/m2), bordex mixture, champ fungicide, and lime powder). This
investigation revealed that amending the soil with lime powder at a rate of 500 g/m2 (T-5) proved
to be the most suitable and effective method for controlling bacterial wilt disease and improving
flowering and fruit formation. This method demonstrated not only high efficacy but also costeffectiveness
and environmental friendliness compared to other treatments. Additionally, Bordex
mixture and Champ fungicide exhibited moderate activity in disease control. Findings of this
research provide valuable insights into the management of bacterial wilt disease in bitter gourd
cultivation, emphasizing the importance of adopting eco-friendly and cost-effective methods for
sustainable agriculture.