Hemp seed priming via different agents to alleviate temperature stress

Abstract

Soil temperature is an important factor in seed germination especially low soil temperature causes retarded and unsynchronized germination, emergence and seedling growth. These issues are causing the seedlings vulnerable to diseases and weed infestation during stand establishment of hemp. This study includes different seed priming agents (water, -0.8 MPa PEG 6000, 50 mMol thiamine and 10 mMol mannitol). These priming agents were controlled under different temperatures (10, 15, 20, 25 and 30 °C) to evaluate their potential for promoting germination and seedling growth. Results revealed that seed treatment gave accelerated mean germination time, increase emergence percentage at lower temperatures. Seed pre-treatments also promoted shoot length in all temperatures. However root length promoting effects of seed pre-treatments were more evident at 10, 15 and 20 °C. Seedling fresh and dry weight reached maximum values at 20 °C with water, thiamine and mannitol treatments. Chlorophyll and leaf proline content reached their higher values at 20, 25 and 30 °C. Overcoming temperature stress and promoting germination is important for hemp development. It was concluded that hemp seeds primed with water, thiamine, and mannitol had the highest biomass values for low, optimum, and high temperatures in this paper that makes these seed treatments suitable for hemp plants that could come across low or high temperatures during germination and early growth stages.