Tran Jonathan, Dimech Adam M, Vassiliadis Simone, Elkins Aaron C, Cogan Noel O I, Naim-Feil Erez, Rochfort Simone J
Agriculture Victoria Research, Department of Energy, Environment and Climate Action, AgriBio Centre for Agribioscience, Bundoora, Melbourne, VIC 3083, Australia.
School of Applied Systems Biology, La Trobe University, Bundoora, Melbourne, VIC 3083, Australia.
Plants (Basel). 2025 May 20;14(10):1532. doi: 10.3390/plants14101532.
L. is cultivated for therapeutic and recreational use. Delta-9 tetrahydrocannabinol (THC) and cannabidiol (CBD) are primarily responsible for its psychoactive and medicinal effects. As the global cannabis industry continues to expand, constant review and optimization of horticultural practices are needed to ensure a reliable harvest and improved crop quality. There is currently uncertainty about the optimal harvest time of , i.e., when cannabinoid concentrations are at their highest during inflorescence maturation. At present, growers observe the color transition of stigmas from white to amber as an indicator of harvest time. This research investigates the relationship between stigma color and cannabinoid concentration using liquid chromatography-mass spectrometry (LCMS) and digital image analysis. Additionally, early screening prediction models have also been developed for six cannabinoids using near-infrared (NIR) spectroscopy and LCMS to assist in early cannabinoid determination. Among the genotypes grown, 22 of 25 showed cannabinoid concentration peaks between the third (mostly amber) and fourth (fully amber) stages; however, some genotypes peaked within the first (no amber) and second (some amber) stages. We have determined that the current 'rule of thumb' of harvesting when a cannabis plant is mostly amber is still a useful approximation in most cases; however, studies on individual genotypes should be performed to determine their individual optimal harvest time based on the desired cannabinoid profile or total cannabinoid concentration.
大麻因治疗和娱乐用途而被种植。Δ-9 四氢大麻酚（THC）和大麻二酚（CBD）是其产生精神活性和药用效果的主要原因。随着全球大麻产业的持续扩张，需要不断审查和优化园艺实践，以确保可靠的收成并提高作物质量。目前，关于大麻的最佳收获时间存在不确定性，即在花序成熟期间大麻素浓度何时最高。目前，种植者将柱头颜色从白色变为琥珀色作为收获时间的指标。本研究使用液相色谱 - 质谱联用（LCMS）和数字图像分析来研究柱头颜色与大麻素浓度之间的关系。此外，还使用近红外（NIR）光谱和LCMS为六种大麻素开发了早期筛选预测模型，以协助早期大麻素测定。在所种植的基因型中，25个中有22个在第三阶段（大多为琥珀色）和第四阶段（完全为琥珀色）之间出现大麻素浓度峰值；然而，一些基因型在第一阶段（无琥珀色）和第二阶段（有一些琥珀色）内达到峰值。我们已经确定，目前当大麻植株大多为琥珀色时进行收获的“经验法则”在大多数情况下仍然是一个有用的近似方法；然而，应该对个体基因型进行研究，以根据所需的大麻素谱或总大麻素浓度确定其个体最佳收获时间。
