Studying the effect of morphotype and harvest season on yield and quality of Indian genotypes of Centella asiatica: A potential medicinal herb cum underutilized green leafy vegetable
M. R. Rohini, G.R. Smitha
Abstract
Centella asiatica (L.) Urban commonly known as Gotukola is an important medicinal herb cum nutrient rich green leafy vegetable. The present investigation was undertaken at ICAR-Indian Institute of Horticultural Research, Bengaluru to evaluate thirteen accessions of Centella asiatica collected from different agroclimatic zones of India viz., Northern, North eastern and Southern India for studying the effect of morphotype and harvest season on biomass yield and secondary metabolite content. The study was conducted for two consecutive years (2019 and 2020) for two seasons (March and July). Observations for mature leaf size (4 and 8 month after planting) in the studied genotypes depicted the presence of small leaved (1–20 cm2) and broad-leaved accessions (>20 cm2) which differed significantly with respect to fresh biomass yield and secondary metabolite content. Accessions, IIHR-CA-17 and IIHR-CA-18 recorded highest mean fresh biomass yield of 13.95 t and 13.11 t ha−1year−1 and were on par with each other. Both these accessions can be recommended for the leafy vegetable type, whereas accessions, IIHR-CA-13 and IIHR-CA-23 recorded the highest mean total triterpenoid content of 5.07% and 5.03% during 2019 and 6.88% and 6.69% during 2020, respectively showing their promising potential as medicinal types. Pearson's correlation studies showed that the leaf size and asiaticoside content is significantly negatively correlated inferring that the small leaved accessions reported higher secondary metabolite content as compared to the broad-leaved accessions. The study also showed that coinciding harvest with the summer season (March) under Bengaluru conditions (temperature and relative humidity ranges from 33 to 35 °C and 35–38%, respectively) recorded higher biomass yield and high retention of bioactive content. Thus, the study concluded that under Indian conditions, the selection of small leaved genotypes and harvesting during summer months will be beneficial for the farmers as well as herbal industries for obtaining higher yield.