Factors influencing germination and seedling emergence of corncockle (Agrostemma githago): insights for weed management in agricultural systems

Abstract

Agrostemma githago, a poisonous, noxious, and competitive weed species, can threaten crop yields in various agricultural regions worldwide. Experiments were performed twice to ascertain the effect of temperature, salt stress, osmotic potential, and burial depth on the germination and seedling emergence of A. githago. Seeds germinated across various temperatures ranging between 5 and 35 °C, while germination was completely inhibited at 40 °C. The optimum temperature for maximum germination percentage (GP), maximum germination rate (GR), and minimum mean germination time (MGT) ranged from 17.47 °C to 19.37 °C. The 50% reduction in GP occurred at 27 °C. The seeds of A. githago germinated over a wide range of osmotic potentials, from 0 to –1.2 MPa. However, the GP decreased with increasing osmotic potential, where at –1.2 MPa, germinability was 19%. Similarly, seeds germinated across a broad range of salinities, with a GP of 21% at 300 mM. However, no germination was observed at 350 mM. Osmotic potential and salinity concentration required to inhibit 50% of maximum GP were estimated to be −0.99 MPa and 272 mM, respectively. Thus, it is expected that A. githago can germinate in saline and arid environments. The maximum seedling emergence (99%) was observed when seeds were placed on the soil surface. In contrast, no seedling emergence was recorded when seeds were buried at depths greater than 4 cm. Accordingly, deep conventional tillage might be helpful for managing A. githago. This knowledge can be implemented for both the future research and the development of effective management for A. githago.