Influence of environmental factors on seed germination and seedling emergence of Dinebra retroflex

Abstract

In order to evaluate germination response of Dinebra weed to alternating temperatures and (40/30, 35/25, 30/20 and 25/15 °C day/night) in two light conditions (light/dark and continuous dark), osmotic stress (0, -0.2, -0.4, -0.6, -0.8, 1-, and -1.2 MPa), salt stress (0, 50, 100, 150, 200, 250, 300, and 350 mM) and seed burial depth (0, 0.5, 1, 2, 4, 6, and 8 cm), four separate experiments were conducted at Agricultural Sciences and Natural Resources University of Khuzestan during 2019 with four repetitions. The highest germination percentage was observed at alternating temperatures 30/20 °C in light/dark (93 percentage) and the lowest at 25/15 °C in continuous dark condition (5 percentage). Also, the germination percentage was higher in light/dark than continuous dark condition. Salinity and drought stresses required to inhibit 50% germination of the maximum germination were 54 mM and -0.49 MPa, respectively. Also, with increasing the seed burial depth, the emergence of Dinebra decreased and stopped completely at depth of 2cm. The results indicated that this weed is sensitive to salinity and drought. It is recommended to use plowing (especially at night) and planting in the temperature range of 25/15 °C in the integrated weed management program to reduce the emergence seedlings.