Effect of environmental factors, seed burial depth and straw mulch on germination and seedling emergence in Cichorium glandulosum

Abstract

Cichorium glandulosum Boiss. et Huet is a species that has recently spread widely in the autumn crops of northwestern Iran. A study was conducted to evaluate the effect of environmental factors on the germination, emergence, and management of two populations of CG. The effects of temperature, photoperiod, NaCl concentration, osmotic potential, seed burial depth, and straw mulch were evaluated on seed germination and seedling emergence of two populations of C. gladulosum from Tabriz and Marand, Iran. The highest germination percentage was observed in the Tabriz population (93%) and Marand (94%) at 20/10C (day/night). In both populations, germination was 82-93% across a wide range of light/dark periods (8-24 hours of light). However, germination was significantly reduced (∼ 70%) under continuous darkness. The osmotic potential required to inhibit 50% of germination was 0.68 MPa for the Tabriz population and 0.62 MPa for the Marand population. The concentration of NaCl required to inhibit 50% of germination was 4.76 dS m-1 for the Tabriz population and 3.81 dS m-1 for the Marand population. The seed burial depths that caused a 50% decrease in emergence for the Tabriz and Marand populations were 1.86 cm and 2.22 cm, respectively. In the populations of Tabriz and Marand, the application of 6 t ha-1 of straw mulch resulted in a decrease in C. gladulosum emergence to 3% and 10%, respectively. This study’s results inform the conditions required for C. glandulosum germination and establish a theoretical and practical foundation for predicting, preventing, and managing this species using scientific principles C. glandulosum.