scholarly journals Increasing Inflorescence Dry Weight and Cannabinoid Content in Medical Cannabis Using Controlled Drought Stress

HortScience ◽  
2019 ◽  
Vol 54 (5) ◽  
pp. 964-969 ◽  
Author(s):  
Deron Caplan ◽  
Mike Dixon ◽  
Youbin Zheng
Keyword(s):  
Drought Stress ◽  
Cannabis Sativa ◽  
Dry Weight ◽  
Leaf Angle ◽  
Management Technique ◽  
Medical Cannabis ◽  
Stress Threshold ◽  
Cannabidiolic Acid ◽  
Plant Water Potential ◽  
Effects Of Drought

Controlled application of drought can increase secondary metabolite concentrations in some essential oil-producing crops. To evaluate the effects of drought on cannabis (Cannabis sativa L.) inflorescence dry weight and cannabinoid content, drought stress was applied to container-grown cannabis plants through gradual growing substrate drying under controlled environment. Fertigation was withheld during week 7 in the flowering stage until midday plant water potential (WP) was approximately −1.5 MPa (drought stress threshold). This occurred after 11 days without fertigation. A well-irrigated control was used for comparison. Leaf net photosynthetic rate (Pn), plant WP, wilting (leaf angle), and volumetric moisture content (VMC) were monitored throughout the drying period until the day after the drought group was fertigated. At the drought stress threshold, Pn was 42% lower and plant WP was 50% lower in the drought group than the control. Upon harvest, drought-stressed plants had increased concentrations of major cannabinoids tetrahydrocannabinol acid (THCA) and cannabidiolic acid (CBDA) by 12% and 13%, respectively, compared with the control. Further, yield per unit growing area of THCA was 43% higher than the control, CBDA yield was 47% higher, ∆9-tetrahydrocannabinol (THC) yield was 50% higher, and cannabidiol (CBD) yield was 67% higher. Controlled drought stress may therefore be an effective horticultural management technique to maximize both inflorescence dry weight and cannabinoid yield in cannabis, although results may differ by cannabis cultivar or chemotype.

scholarly journals The Highs and Lows of P Supply in Medical Cannabis: Effects on Cannabinoids, the Ionome, and Morpho-Physiology

2021 ◽  
Vol 12 ◽  
Author(s):  
Sivan Shiponi ◽  
Nirit Bernstein
Keyword(s):  
Environmental Conditions ◽  
Cannabis Sativa ◽  
Maximum Yield ◽  
Dilution Effect ◽  
P Uptake ◽  
Medical Cannabis ◽  
Cannabidiolic Acid ◽  
Growing Conditions ◽  
And Function ◽  
P Supply

Environmental conditions, including the availability of mineral nutrients, affect secondary metabolism in plants. Therefore, growing conditions have significant pharmaceutical and economic importance for Cannabis sativa. Phosphorous is an essential macronutrient that affects central biosynthesis pathways. In this study, we evaluated the hypothesis that P uptake, distribution and availability in the plant affect the biosynthesis of cannabinoids. Two genotypes of medical “drug-type” cannabis plants were grown under five P concentrations of 5, 15, 30, 60, and 90 mg L–1 (ppm) in controlled environmental conditions. The results reveal several dose-dependent effects of P nutrition on the cannabinoid profile of both genotypes, as well as on the ionome and plant functional physiology, thus supporting the hypothesis: (i) P concentrations ≤15 mg L–1 were insufficient to support optimal plant function and reduced photosynthesis, transpiration, stomatal conductance and growth; (ii) 30–90 mg L–1 P was within the optimal range for plant development and function, and 30 mg L–1 P was sufficient for producing 80% of the maximum yield; (iii) Ionome: about 80% of the plant P accumulated in the unfertilized inflorescences; (iv) Cannabinoids: P supply higher than 5 mg L–1 reduced Δ9-tetrahydrocannabinolic acid (THCA) and cannabidiolic acid (CBDA) concentrations in the inflorescences by up to 25%. Cannabinoid concentrations decreased linearly with increasing yield, consistent with a yield dilution effect, but the total cannabinoid content per plant increased with increasing P supply. These results reveal contrasting trends for effects of P supply on cannabinoid concentrations that were highest under <30 mg L–1 P, vs. inflorescence biomass that was highest under 30–90 mg L–1 P. Thus, the P regime should be adjusted to reflect production goals. The results demonstrate the potential of mineral nutrition to regulate cannabinoid metabolism and optimize pharmacological quality.

scholarly journals Effects of Drought Stress on Biomass, Essential Oil Content, Nutritional Parameters, and Costs of Production in Six Lamiaceae Species

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 573 ◽  
Author(s):  
Pedro García-Caparrós ◽  
María Romero ◽  
Alfonso Llanderal ◽  
Pedro Cermeño ◽  
María Lao ◽  
...  
Keyword(s):  
Drought Stress ◽  
Essential Oil ◽  
Water Deficit ◽  
Oil Content ◽  
Dry Weight ◽  
Experimental Period ◽  
Raw Material ◽  
Mentha Piperita ◽  
Effects Of Drought ◽  
Lavandula Latifolia

Lamiaceae is one of the largest families of aromatic plants and it is characterized by the presence of external glandular structures which produce essential oils highly valued in cosmetics and medicine. Plants of Lavandula latifolia, Mentha piperita, Salvia sclarea, Salvia lavandulifolia, Thymus capitatus, and Thymus mastichina were grown for one year. In order to evaluate the effects of drought stress, plants were subjected to two water treatments (100% ETo and 70% ETo, including the rainfall during the experimental period). At the end of the experiment, the biomass, the essential oil content, and leaf nutrients concentration were assessed for each water treatment and species studied. At the end of the experiment, L. latifolia, M. piperita and T. capitatus plants showed a significant fresh weight reduction under drought stress conditions whereas the other species studied remained unchanged. With respect to dry weight, only L. latifolia plants showed a reduction under water deficit conditions. As far as essential oil content was concerned, L. latifolia and S. sclarea plants had a reduction under water deficit conditions. Leaf nutrient concentration showed different trends between species considering the nutrient assessed. The economic viability of the growth of this species will be dependent on the benefits achieved which are related to yield production obtained and the price accorded for both raw material and the essential oil extracted.

scholarly journals Alleviation of drought stress by silicon supplementation in pistachio (Pistacia vera L.) plants

2013 ◽  
Vol 25 (1) ◽  
pp. 21-29 ◽  
Author(s):  
Ghader Habibi ◽  
Roghieh Hajiboland
Keyword(s):  
Drought Stress ◽  
Photochemical Efficiency ◽  
Dry Weight ◽  
Pistacia Vera ◽  
Antioxidant Defence ◽  
Photosynthetic Gas Exchange ◽  
Relative Water ◽  
Effects Of Drought ◽  
Net Assimilation ◽  
Quantum Yield Of Psii

ABSTRACT The effect of silicon (Si) supplementation (0.35 g Na2SiO3 kg-1 soil, 2.73 mmol Si kg-1 soil) was studied in drought-stressed pistachio (Pistacia vera L. ‘Ahmadaghaii’) plants under field conditions. Silicon treatment significantly increased plant dry weight and relative water content under drought stress. The application of Si for drought-stressed plants improved the maximum quantum yield of PSII. A reduction in the net assimilation rate due to drought stress was alleviated by Si application, accompanied by an increase in stomatal conductance. Silicon treatment resulted in higher catalase and superoxide dismutase activities and lower lipid peroxidation in the leaves of drought-stressed plants. The results suggest that supplementation of water-deficient pistachio plants with Si alleviates the adverse effects of drought due to its enhancement of photochemical efficiency and photosynthetic gas exchange, as well as an activation of the antioxidant defence capacity in this species.

Uniconazole mitigates disadvantageous effects of drought stress on Cannabis sativa L. seedlings

2021 ◽  
Vol 54 (1) ◽  
Author(s):  
Ying Jiang ◽  
Naijie Feng ◽  
Yufeng Sun ◽  
Dianfeng Zheng ◽  
Chengwei Han ◽  
...  
Keyword(s):  
Drought Stress ◽  
Cannabis Sativa ◽  
Effects Of Drought

scholarly journals Optimal Rate of Organic Fertilizer during the Flowering Stage for Cannabis Grown in Two Coir-based Substrates

HortScience ◽  
2017 ◽  
Vol 52 (12) ◽  
pp. 1796-1803 ◽  
Author(s):  
Deron Caplan ◽  
Mike Dixon ◽  
Youbin Zheng
Keyword(s):  
Nutrient Management ◽  
Cannabis Sativa ◽  
Organic Fertilizer ◽  
Growth Index ◽  
Dry Weight ◽  
Organic Fertilizers ◽  
Growth And Yield ◽  
Organic Substrates ◽  
Medical Cannabis ◽  
Fertilizer Rates

In the expanding North American medical cannabis industry, growers lack reliable and systematically investigated information on the horticultural management of their crops, especially with regard to nutrient management and growing substrates. To evaluate organic substrates and their optimal nutrient management, five rates that supplied 57, 113, 170, 226, and 283 mg N/L of a liquid organic fertilizer (2.00N–0.87P–3.32K) were applied to container-grown plants [Cannabis sativa L. ‘WP:Med (Wappa)’] in two coir-based organic substrates. The trial was conducted in a walk-in growth chamber and the two substrates used were ABcann UNIMIX 2-HP (U2-HP) with lower container capacity (CC) and ABcann UNIMIX 2 (U2) with higher CC. U2-HP produced 11% higher floral dry weight (yield), 13% higher growth index (GI), 20% higher ∆9-tetrahydrocannabinol (THC) concentration, 57% higher THC yield (per plant), 22% higher Δ9-tetrahydrocannabidiolic acid (THCA) yield, and 20% higher cannabigerolic acid (CBGA) yield than U2. Increasing fertilizer rate led to increased growth and yield but also to a dilution of THC, THCA, and CBGA. In U2-HP, to maximize both yield and cannabinoid yield, the optimal organic fertilizer rates were those which supplied 212–261 mg N/L. For U2, the highest applied rate, that supplied 283 mg N/L, maximized yield; although lower rates delivered higher cannabinoid concentrations in dry floral material. The results on these substrates and recommended fertilizer rates can serve as a guide when using other organic fertilizers and substrates; although results may differ with cannabis variety.

scholarly journals The Impacts of Drought Stress and Phytophthora cinnamomi Infection on Short-Term Water Relations in Two Year-Old Eucalyptus obliqua

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 109
Author(s):  
Mashlahatul Umami ◽  
Linda M. Parker ◽  
Stefan K. Arndt
Keyword(s):  
Drought Stress ◽  
Water Relations ◽  
Phytophthora Cinnamomi ◽  
Cumulative Effect ◽  
Biomass Accumulation ◽  
Short Term ◽  
Shoot Ratio ◽  
Plant Water Potential ◽  
Plant Photosynthesis ◽  
Effects Of Drought

The effects of drought stress, Phytophthora cinnamomi infection and their interaction on water relations and growth were examined for 28 days on two year-old potted trees of Eucalyptus obliqua (L’Hér.). There were significant effects of drought stress on plant photosynthesis, stomatal conductance, biomass accumulation, plant water potential at turgor loss point and the bulk modulus of elasticity. E. obliqua was successfully infected but the trees showed only mild symptoms. Infection with P. cinnamomi led to a significant reduction in the root biomass and root-to-shoot ratio in well-watered and droughted plants but did not impact water relations. There was no observable cumulative effect of drought and P. cinnamomi infection. There are multiple potential reasons why P. cinnamomi infection did not lead to drought-like symptoms in E. obliqua, including short experimental duration, delayed infection symptoms, potential resistance of E. obliqua and a possible lower aggressiveness of the P. cinnamomi strain. Hence, our results indicate that P. cinnamomi infection will not always lead to immediate short-term symptoms, and that plants that are mildly symptomatic respond very similar to drought stress compared to non-infected trees.

Effect of Drought Stress on Velvetleaf (Abutilon theophrasti) and Bentazon Efficacy

Weed Science ◽  
1994 ◽  
Vol 42 (1) ◽  
pp. 76-81 ◽  
Author(s):  
John R. Hinz ◽  
Michael D. K. Owen
Keyword(s):  
Drought Stress ◽  
Water Potential ◽  
Soil Water Potential ◽  
Dry Weight ◽  
Abutilon Theophrasti ◽  
Leaf Water ◽  
Urea Ammonium Nitrate ◽  
Effects Of Drought ◽  
Osmotic Potentials ◽  
Over Time

Greenhouse experiments were conducted to determine the effects of drought stress length and relief on velvetleaf growth and bentazon efficacy with crop oil concentrate (COC) and 28% urea ammonium nitrate (UAN). Drought stress caused leaf water and osmotic potentials to decline linearly over time. Leaf water potential ΨL) declined 0.02 and 0.08 MPa day−1for velvetleaf subjected to −0.03 and −0.4 MPa soil water potential (ΨP), respectively. Osmotic potential (ΨO) declined 0.02 and 0.21 MPa day−1for velvetleaf subjected to −0.03 and −0.4 MPa ΨPrespectively. Bentazon did not reduce drought-stressed compared to non-drought-stressed velvetleaf dry weight 21 d after treatment with either COC or no adjuvant but did decrease dry weight with UAN. Reduced velvetleaf dry wights in drought-stressed velvetleaf compared to non-drought-stressed velvetleaf could not be accounted for by increased bentazon penetration in the drought-stressed plants. Rewatering velvetleaf subjected to 7 d of −0.4 MPA ΨPcaused them to be more sensitive to bentazon than velvetleaf subjected to −0.03 MPa ΨPexcept when UAN was the adjuvant.

scholarly journals Exogenous Application of Silicon Can Help Augment Drought Tolerance in Wheat (Triticum aestivum L.) by Enhancing Morpho-physiological and Antioxidant Potential

2021 ◽  
Author(s):  
Muhammad Aurangzaib ◽  
Zahoor Ahmad ◽  
Muhammad Imran Jalil ◽  
Muhammad Faheem Nawaz ◽  
Muhammad Rashid Shaheen ◽  
...  
Keyword(s):  
Drought Stress ◽  
Biomass Yield ◽  
Flag Leaf ◽  
Dry Weight ◽  
Potassium Silicate ◽  
Chlorophyll Contents ◽  
Exogenous Application ◽  
Effects Of Drought ◽  
Total Dry Weight ◽  
1000 Grain Weight

Abstract Drought stress is considered one of the most severe stresses, which can result in devastating yield reduction in agriculture crops. There are many approaches recommended by the researchers and adopted by the farmers to minimize the devastating effect of drought. However, exogenous application of growth regulators in combination to plant nutrients is the innovative attitude to ameliorate the shocking effects of drought stress. So we planned a study to investigate the ameliorative effect of exogenously applied potassium silicate wheat (Triticum aestivum L.) crop under water deficit conditions. The current study was conducted at the Agronomic Research Farm area, Faculty of Agriculture and Environment, The Islamia University of Bahawalpur. RCBD-Split plot design with four repeats was used. The treatments consist on “T0” (Control), “T1” (exogenous application of potassium silicate @ 1% solution), “T2” (exogenous application of potassium silicate @ 2% solution), “T3” (exogenous application of potassium silicate @ 3% solution). The results of our study revealed that drought stress can significantly affect crop yield as a result of the reduction in chlorophyll-a (1.07), chlorophyll-b (0.49), total chlorophyll contents (1.62), flag leaf area (38.33 cm2), plant height (100.17cm), number of nodes per plant (3.91), tiller height (92.42), number of tillers m− 2 (191.17), spike length (7.58 cm), number of spikes per plant (10.25), number of grains per spike (25.08), 1000-grain weight (36.66g), total dry weight per plant (309.75g), biomass yield (23424kg/ha) and grain yield (4564.2 kg/ha). On the other hand, the exogenous application of potassium silicate at 2% solution showed promising results in terms of ameliorating the drought effect by significantly enhancing chlorophyll-a (1.21), chlorophyll-b (0.64), total chlorophyll contents (1.92), flag leaf area(45.25 cm2), plant height (123.50cm), number of nodes per plant (5.25), tiller height (99.42), number of tillers m− 2 (276.26), spike length (12.92cm), number of spikes per plant (14.25), number of grains per spike (38.33), 1000-grain weight (44.33g), total dry weight per plant (385.00g), biomass yield (24000 kg/ha) and grain yield (5074.8kg/ha). These findings led us to conclude that the exogenous application of potassium silicate has a great ability to compensate for the detrimental effects of drought in wheat crops.

scholarly journals Effects of Drought Stress on Growth and Accumulation of Proline in Five Rice Varieties (Oryza Sativa L.)

2019 ◽  
Vol 45 (2) ◽  
pp. 241-247
Author(s):  
Shukanta Saha ◽  
Hasna Hena Begum ◽  
Shamima Nasrin
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Oryza Sativa L ◽  
Dry Weight ◽  
Proline Accumulation ◽  
Shoot Length ◽  
Fresh Weight ◽  
Rice Varieties ◽  
Shoot Dry Weight ◽  
Effects Of Drought

A pot experiment was conducted to study the effect of drought stress on growth and accumulation of proline in five rice varieties namely BRRI dhan-30, BRRI dhan-32, BRRI dhan-34, BRRI dhan-38 and BRRI dhan-56 and to characterize them on the basis of their behavior of drought tolerance. Drought stress caused the decrease of growth like root length, shoot length, root fresh weight, shoot fresh weight, root dry weight, shoot dry weight, the ratio of root-shoot length. Among the rice varieties, BRRI dhan-56 showed the lowest decrease of growth of plant. BRRI dhan-56 showed the least decrease of water content in both root and shoot. On the other hand, the accumulation of proline was increased in five rice varieties under stress. BRRI dhan-56 showed the highest (3.7- folds) increase in the accumulation of proline in leaf under stress. This study suggests that BRRI dhan-56 may possess drought tolerance characteristics while BRRI dhan-30, BRRI dhan-32, BRRI dhan-34 and BRRI dhan-38 may be drought sensitive based on their growth and proline accumulation behavior. Asiat. Soc. Bangladesh, Sci. 45(2): 241-247, December 2019

Enhancement of physiological and biochemical attributes of okra by application of salicylic acid under drought stress

2020 ◽  
pp. 113-119
Author(s):  
Qasim Ayub ◽  
Shah Masaud Khan ◽  
Abid Mahmood ◽  
Naveed Ul Haq ◽  
Shujaat Ali ◽  
...  
Keyword(s):  
Drought Stress ◽  
Chlorophyll A ◽  
Total Protein ◽  
Electrolyte Leakage ◽  
Dry Weight ◽  
Chlorophyll B ◽  
Fresh Weight ◽  
Total Carotenoids ◽  
Effects Of Drought ◽  
Physiological And Biochemical

Horticultural crops especially vegetables are most vulnerable to drought due to their higher irrigation needs. Hence, this study was undertaken to evaluate the adverse effects of drought stress and the beneficial effects of salicylic acid (SA) on physiological and biochemical attributes of okra plants under drought stress. For this purpose, a pot experiment was laid out in Complete Randomized Design (CRD) design. Okra seeds were primed with four different SA treatments i.e., 0 (control), 1, 2 and 3 mM and sown in pots (Ø 20 cm). After 14 days of germination, the plants were subjected to two drought levels i.e., 25% and 50% field capacity (FC) and after 20 days of germination regular foliar sprays of SA at 7 days interval were performed with aforementioned SA levels. Physiological parameters like fresh weight, dry weight, and length of plants along with biochemical attributes like chlorophyll (‘a’, ‘b’ and total), total carotenoids, total protein and proline contents, and electrolyte leakage were recorded. Results revealed that drought stress (25% FC) significantly reduced all the studied parameters and resulted in the lowest values of fresh weight (5.04 g), dry weight (1.33 g), length of plants (11.68 cm), chlorophyll ‘a’ content (5.97 mg/g FW), chlorophyll ‘b’ content (8.86 mg/g FW), total chlorophyll (14.84 mg/g FW), total carotenoids (4.96 mg/g FW) and total protein (1.05 mg/g FW), except proline content (6.81 mg/g FW) and electrolyte leakage (77.31%) which was increased. Application of SA under drought stress reduced the harmful effects of drought and application of 2 mM SA produced the maximum fresh weight (8.60 g), dry weight (2.51 g), length of plants (16.23 cm), chlorophyll ‘b’ content (14.47 mg/g FW), total protein (3.73 mg/g FW) and proline content (5.11 mg/g FW); whereas application of 3 mM SA showed the highest values of chlorophyll ‘a’ (8.91 mg/g FW), total chlorophyll content (23.20 mg/g FW) and carotenoids (7.93 mg/g FW), and the lowest value for electrolyte leakage (62.00%).

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