This article is the third in a three-part series describing potato plants’ three most critical potato hormones. Once again, we turn to University of Manitoba plant researcher Mark Belmonte to help explain the science of hormones. In the first two articles, we discussed the function and economic benefits of gibberellic acid (GA) and auxin. Today, we’re tackling key the third key potato hormone — cytokinin.
Brodie Workman (BM): Mark, what function does cytokinin play in a potato plant’s germination and growth?
Mark Belmonte (MB): Whereas gibberellic acid initiates germination and elongates cells, and auxin initiates cell production and differentiation; cytokinin is the cell divider. Cell division is obviously critical to growth, but there’s more to it than that. Plant cells form the architecture of the plant. The more cells there are, the more cell wall there is. Cells walls are responsible for a plant’s form and function and for providing a plant’s strength. So, cytokinin is critical for helping a plant get out of the ground and for keeping its stem standing upright.
Cytokinin also plays other key roles in a potato plant. It’s responsible for making more stems, which turn into more branches, more photosynthesis, and ultimately more yield. It’s also responsible for keeping flowers on the plant and for seed fertilization, and it plays important roles in other row crops where the seed is what’s harvest compared to the tuber of potato.
BM: Last month, you explained that, though synthetic versions exist of each of the three key potato hormones, the best benefit comes from applying them in combination.
MB: It’s true. Nature is all about balance. In particular, cytokinin and auxin work very much hand-in-hand: both are fundamental to the creation of new cells.
As a scientist, I look to nature for guidance. If a plant naturally depends on three major hormones for germination and growth, supplementing just one or another of the three will push the plant out of balance. For best results, we always want to mimic nature’s own design and processes. Our trial results certainly prove that the greatest growth and yield boost comes from balanced supplementation of GA, auxin and cytokinin.