Efficiency of Chemical and Mechanical Priming in Breaking Seed Dormancy and Germination Traits of Malva (Malva neglcta)

Extended abstract Introduction: Malva (Malva neglecta) is one of perennial plants of the Malvaceae family. One of the most important mechanisms for survival of the plants is dormancy, rest or distance in germination and growth; in this case, despite favorable conditions for germination, the seed remains at rest for an indefinite period of time. Seed dormancy is a consistent feature in some seeds, especially weed seeds to optimize distribution of germination over time. Seed dormancy has a very important role in ecological management. The cause of the physical dormancy lies in skin cells outside tier structure that is impermeable to water. In physical dormancy, the seed coat is so hard that it does not allow the embryo to grow during germination. The chemical dormancy of the plants seeds is caused by the presence of inhibitor substances in the outer shell of many fruits and seeds and may also be due to an Enamel layer that blocks the exchange of oxygen. It goes without saying that understanding the ecology of weed germination and dormancy can contribute to long-term management. Therefore, this study was conducted to determine the effects of breaking seed dormancy and the impact of chemical and mechanical treatments on the germination of the Mallow seeds. Materials and Methods: In order to recognize the effects of chemical and mechanical treatments on breaking seed dormancy and some of the most important features of seed germination of Malva, the experiment was conducted based on a completely randomized design with 4 replications at Crop Physiology Lab, Razi University, during 2016. Treatments were distilled water (control), sulfuric acid 98% (for 2, 3 and 4 minutes), potassium nitrate 3% (for 3, 4 and 7 days), hydrogen peroxide 30% (for 2, 3 and 4 minutes) and scarification with sandpaper and prechilling (for 1, 2 and 3 weeks). Germination percentage, germination rate, length and dry weight of hypocotyl, length and dry weight of radicle, seedling total dry weight and vigor index were evaluated. Group comparisons, analysis of variance and comparison of means were run based on LSD at 5% level, using SAS software (version 9.4). Results: The results showed that the highest and the lowest germination percentage were 82% and 5% in scarification with a chilling for 3 weeks and control treatments, respectively. The results of treatment group comparisons also showed that using scarification with a chilling had the greatest impact on seed dormancy breaking. The most h