Effect of environmental factors on seed germination and emergence of <i>Lepidium vesicarium</i>

Abstract

Abstract L epidium vesicarium is a weed species with a wide distribution in the rangelands and dry‐land farming in E ast A zarbaijan, I ran. The experiments were undertaken to assay the effects of light, temperature, pH , osmotic potential, NaCl concentration and burial depth on seed germination and emergence of L . vesicarium . Germination was maintained at high levels (&gt; 80%) over a wide day/night temperature range (10/5 to 30/20°C), but a severe reduction in the germination rate of L . vesicarium was found below 20/10°C. Germination of L . vesicarium was influenced by different light/dark regimes, as the germination rate was highest at 16 h light for the all treatments (0, 8, 12, 16 and 24 h light). Germination was 92–95% over a wide range of pH (2‐10). Germination was &gt;50% at a water potential of −0.7 MPa and salinity of 21 dS /m, indicating that drought and salt conditions have a minimal impact on seed germination. With increasing burial depth from 0 to 2 cm, the number of days required for 50% emergence increased and no germination was observed at burial depths deeper than 3 cm. This suggests that L . vesicarium would become troublesome in the rangelands and for growers in reduced‐tillage cropping systems. The ability to emerge from shallow depths, coupled with tolerance of a wide pH range, drought and salinity at germination, should be taken into account when managing this weed species.