Influence of different environmental factors on the germination and seedling emergence of Ipomoea eriocarpa R. Br.

Abstract

Ipomoea eriocarpa R. Br., an annual prostrate plant, is a troublesome weed species in the tropical and sub-tropical regions of Asia, Africa, and Australia. For a better understanding of the plant's ecology, a seed germination study was conducted in order to predict the weed's ability to increase its global distribution, as well as presenting suitable management strategies for combating its spread. Germination and emergence of I. eriocarpa were examined in order to investigate the impact of abiotic factors such as temperature, salinity, moisture, soil pH, and burial depth on seeds. Germination and growth experiments were conducted under a completely randomized design with four replications. Maximum germination (77.5%) of I. eriocarpa occurred at 25 °C, decreasing according to an increase in temperature. A decrease in germination from 77.5 to 27.5% was observed where salinity increased from 0 to 200 mM of sodium chloride (NaCl). Germination of I. eriocarpa was 75% in no-water stress conditions; however, it gradually decreased with increasing water stress, with 32.5% germination at −0.8 MPa osmotic potential and no germination at −0.1 MPa osmotic potential. Germination was similar (74–76%) at pH levels ranging from 5 to 8 and decreased to 38% at pH 10. Optimal sowing depths ranged from 2 to 6 cm. Emergence decreased to 37.5% and 12.5% at burial depths of 8 and 10 cm, respectively. Our results suggest that I. eriocarpa has the potential to germinate, emerge and survive under different ecological conditions. Soil solarisation, organic manure application, and deep ploughing all respectively assist in altering the soil temperature, soil pH, and seed burial depths of I. eriocarpa, contributing towards the effective management of this weed species.