The effect of temperature on leaf appearance and canopy establishment in fibre hemp (Cannabis sativa L.)

Abstract

SUMMARY The effects of temperature on the development and growth of hemp (Cannabis sativa L.) have never been quantified. Therefore, to establish the effect of temperature on leaf appearance and canopy establishment of fibre hemp under controlled and field conditions, plants were grown in growth chambers at 11 regimes with average temperatures between 10°C and 28°C, and three cultivars were sown in the field in March, April and May in 1990, 1991 and 1992. In the field, thermal time (base 0°C) between sowing and emergence ranged from 68°Cd to 109.5°Cd (average 88.3°Cd). Rates of leaf appearance and stem elongation increased linearly with temperature between 10°C and 28°C. The base temperature for leaf appearance was 5.7°C from the growth chamber experiments and 1°C from the field experiments. In the field, the base temperature for the relationship between light interception by the canopy and thermal time was 2.5°C, and thermal time, calculated at the appropriate base temperature, accounted for about 98% of the variance in the number of leaves and for 98.6% of the variance in the proportion of light intercepted by the canopy. Days from emergence accounted for less of the variance in both parameters than thermal time. Interception of 90% of light was attained on average at 465°Cd (base 0°C) after emergence. It is concluded that thermal time is a simple and accurate tool to describe leaf appearance and light interception in fibre hemp.

Effects of short-term environmental stresses on the onset of cannabinoid production in young immature flowers of industrial hemp (Cannabis sativa L.)

“…In addition, temperature is an important factor for canopy formation in fiber hemp. A study showed that the rate of leaf appearance and stem elongation linearly increased as temperature rises from 10 o C to 28 o C (Van Der Werf et al 1995 ). Due to global warming, agricultural crops including Cannabis plants encounter multiplexed environmental stresses of which extreme heat and drought are the most impactful.…”

Evaluation of Woven Agrotextiles in the Development of Hemp (Cannabis sativa L.) in Greenhouse

“…However, when the temperatures rise above 35 o C, the soil coverage works negatively. Werf et al (1995) observed that rates of leaf appearance and stem elongation increased linearly with temperature between 10°C and 28°C. Kobza et al (1987) noticed that leaf temperature on wheat was 15-25 o C.…”

Cannabis sativa research trends, challenges, and new-age perspectives

“…The first publication with a detailed response of greenhouse cultivated cannabis to nitrogen (N), phosphorus (P), and potassium (K) was published in 1977 (Coffman and Gentner, 1977). Furthermore, two parallel reports by HMG et al, in 1995 discussed the impact of nitrogen fertilization on sex expression in hemp (van der Werf and van den Berg, 1995), and the effect of temperature on leaf and canopy formation (van der Werf et al, 1995). Importantly, most physiological studies in the second and third period (Figure 1A) were published for hemp with a focus on photosynthetic response and biomass yield with varying conditions such as temperature, water availability, nitrogen, and mineral nutrition (Amaducci et al, 2002;Aubin et al, 2015;Finnan and Burke, 2013;Papastylianou et al, 2018;Tang et al, 2017Tang et al, , 2018.…”