The effects of soil temperature increasing using plastic mulch on germination traits and alpha and beta amylase in seeds of four spring weed species

Considering the environmental problems due to the usage of chemical herbicides, to control the weeds we can increase soil temperature by mulching. This research was conducted in Fasa in 2020. The experiment was performed as a factorial in a completely randomized design with three replications.The first factor was four varieties of weeds including Amaranthus retroflexus, Chenopodium album, Portulaca oleracea and Plantago lancoelata and the second factor was duration of mulching cover in 3 treatments including control, 20 and 40 days. After the periods of plastic mulching, the seeds were taken out of the soil depth and were examined based on standardized germination test. The results showed that the percentage and rate germination seeds, vigor and alpha and beta amylase decreased with the plastic mulching was used. 40 days of plastic mulching caused a reduction in germination speed comparing to the treatment which had no plastic mulching. By increasing the duration of the usage of mulching, the electric conduction of seeds showed an increase applying plastic mulching for forty days caused a decrease in seedling growth comparing to the treatment. The highest decrease in germination and seed vigor among the weeds was observed in Chenopodium album on the other hand plastic mulching treatment couldn't affect the germination in Plantago lancoelata. Overall, the results of this study showed that the parameters related to seed germination in different weed species was different based on the time of sun exposure under plastic mulch; So that solarization for 40 days is recommended to control weeds.