2019 ASHS Annual Conference

Having originated in the Asian tropics, butterfly pea (Clitoria ternatea) is an herbaceous, perennial leguminous twiner, meaning it climbs by encircling a vertical support. The flowers are a deep blue to purple color and when dried have long been used as a food colorant in Southeast Asian cuisine; the powdered form of C. ternatea flower extract tends to be more convenient, with a longer shelf life, when compared to synthetic blue colorants. The first stage in the plant life cycle, seed germination viability and percentage is influenced by a variety of internal and external factors and can have significant effects on commercial production operations. The following experiment further investigated two other factors influencing seed germination percentage in C. ternatea, substrate and temperature. Three different trials were performed of the same experimental design, one each per week across the span of three weeks from 17 September to 8 October 2018. Two different substrates were utilized for the experiment, the Fafard 4P soilless substrate mix and rockwool, and the propagation unit used consisted of heating mats programmed to maintain 21.1°C (70°F), 26.7°C (80°F) and 32.2°C (90°F) for the top, middle and bottom tiers respectively. Six germination parameters were recorded daily, including germination capacity (G), mean germination time (MT), coefficient of variation of the germination time (CV_t) and mean germination rate (MR). Given the lack of significance observed in the temperature by substrate interaction effect, and with significance in the germination capacity (G) (p value = 0.0344), mean germination time (MT) (p value = 0.0109), coefficient of variation of the germination time (CV_t) (p value = 0.0111) and mean germination rate (MR) (p value = 0.0269) parameters for the substrate independent variable, it can be concluded that the rockwool substrate treatment performed significantly better than the soil substrate treatment. Similarly, significant differences were observed among temperature independent variable treatments in the mean germination time (MT) (p value = 0.0096), coefficient of variation of the germination time (CV_t) (p value = 0.0056) and mean germination rate (MR) (p value = 0.0293) parameters, to which it can be concluded that the 21.1°C (70°F) and 26.7°C (80°F) treatments performed significantly better than the 32.2°C (90°F) treatment. Future research will be conducted to further investigate the influence of temperature, substrate and other independent variables on seed germination percentage in C. ternatea.