Physiological characteristics

Hemp varieties thrive in specific regions, despite their diverse range, it is a highly adaptable plant, capable of growing in a variety of climates and soil types. Light, air and soil temperatures, soil and mineral nutrients, and water availability in the soil are the most important factors impacting hemp growth and development. The following information primarily refers to fibre and seed hemp, however flowering hemp would respond similarly to environmental conditions.

Hemp, like other plants, uses photosynthesis to convert sunlight, carbon dioxide, and water into energy, glucose and oxygen. Hemp is sensitive to day duration, with a crucial photoperiod of around 14 hours that initiates flowering following the juvenile phase. Leaf fall, higher growth respiration for seed synthesis, canopy senescence, and lignin synthesis in the stem all contribute to decreased efficiency following flowering (Gu & Fulk, 2021)

Hemp grows best at temperatures ranging from 19 to 25 degrees Celsius, with base temperature for the emergence and vegetative growth of 1 degree Celsius. Hemp seeds will germinate in 8 to 10 days at soil temperatures of 8 to 10 ºC. The young plants can survive frost as low as-5 ºC until they have four to five pairs of leaves.

Hemp has various physiological mechanisms to protect itself against pests, diseases, and environmental stressors, including the synthesis of secondary metabolites like THC and terpenes. Hemp plants produce a variety of compounds, and 421 compounds from various phytochemical groups have been identified, including nitrogen-containing compounds, fatty acids, steroids, terpenes (mono-, sesqui-, di-, and triterpenes), flavonoids, vitamins, pigments, and, of course, cannabinoids (Fournier et al., 2013).

Numerous investigations have found that the relative proportions of the main cannabinoids are determined by genetic variables, but their concentration is affected by environmental influences (Small, 1979). As previously stated, hemp plants produce cannabinoids such as CBD, CBN, and THC. Hemp produces chemicals that contribute to its medical and therapeutic effects.

Hormones play a crucial role in regulating various physiological processes in hemp, including growth, flowering, and stress responses. Such as uniconazole which is a plant growth retardant (Jiang et al., 2021). However, Hemp is known for its rapid growth rate, typically reaching maturity in about 3 to 4 months. Understanding these physiological characteristics is crucial for optimizing hemp cultivation practices and maximizing yield and quality. In further sections, water, soil and nutrients requirements will be explored in more detail. (Gu & Fulk, 2021).