Article by Emma Stone, Weedmaps News
While many appreciate the therapeutic and recreational benefits of cannabis, few are familiar with the process that governs cannabis flowering, or the conditions that are required for optimal growth.
When cannabis reaches the flowering stage, vegetative growth slows and flower buds begin to appear. As the buds enlarge, the pungent, unmistakably aromatic cannabis scent also intensifies with the development of trichomes, the hairy, resinous glands on the cannabis inflorescence, which comprises the complete flower head of a plant. Cannabis flowers are considered mature and ready to harvest when the trichomes change color from clear to opaque.
New Findings on Cannabis Flowering
There is both a practical and a scientific need to understand flowering development better in order to develop methods of flowering control to increase yield and quality of cannabis flowers.
A new study conducted by Dr. Ben Rimon at the Agricultural Research Organization, Volcani Center of Israel, was published in Frontiers in Plant Science on April 2, 2019. The authors investigated the architecture of cannabis inflorescence, and produced compelling findings.
Short photoperiod affects intensive branching and reduction in shoot length. This morphogenesis results in inflorescence development. However, different cultivars require different photoperiodic conditions. Thus, one variety flowered after only eight short days, while two other varieties required 12 short days to complete development of the first flowers. Appearance of stigmas (female flower organ) in the inflorescence signaled that the female flower is mature and ready to capture pollen.
Cannabis growers have long believed that photoperiodic cannabis plants subjected to long photoperiods remain in a state of vegetative growth. The development of solitary flowers under long photoperiod conditions, however, challenges current understandings of the cannabis physiology. The appearance of these solitary flowers indicates that the plant is not vegetative during long photoperiods as is typically understood.
“The most significant finding, as stated in the article, is that a short photoperiod orchestrates intense branching, producing inflorescence structure, with floral initiation that occurs independently of short photoperiod,” Mirza wrote.
The study’s authors suggest that the flower initiation is not due to the onset of short photoperiodic conditions, but rather more likely to be influenced by the age of the plant, the mother plant’s development, and internal signals.
“The study will certainly help in furthering understanding of cannabis plant physiology,” Mirza wrote. “The (immediate) implications are that commercial growers must change their thinking and management practices because flowering initiation occurs independently of short photoperiod.”
The new research also provides growers with insights that can assist them in better understanding the interaction between vegetative and generative growth periods which may reduce costs associated with lighting.
From a research, development and breeding perspective, the weight of this study is substantial. “The results lay a foundation for a more profound molecular exploration of cannabis flowering systems, and provide a basis to more closely explore the interplay between flowering initiation and branching, and open new avenues to both classical and molecular breeding of this important plant”, reflects Prof. Rina Kamenetsky, flowering expert from Israel.
The study’s contribution also holds implications for genetic and biotechnological applications that seek to manipulate the architecture of the cannabis plant to maximize productivity and uniformity of inflorescence.