As previously mentioned, our class went on a trip to a winery and vineyard last week. During the visit, I learned a great deal about the entire wine-making process, from growing grapes to aging the wine in wooden barrels. During the tour through the vineyard, our guide mentioned that they only use herbicides on their crops once a year, at most. During the tour I assumed this was in large part due to environmental concerns. However, while I was looking through the packet we were given, on our way back from the winery, I learned that excessive use of the herbicide also caused the risk of lost crops, rather than simply eliminating weeds.
2,4-Dichlorophenoxyacetic acid (2,4-D) is a common herbicide used to control weed growth and is found in many forms. It is typically applied as an amine salt, but more potent ester forms can also be used. However, because of their extreme volatility, these compounds can also injure grape vines from a considerable distance from the point of application. The herbicide is a synthetic plant growth regulator, and mimics a natural plant growth hormone, auxin. However, application of the herbicide causes uncontrollable growth that eventually results in plant death.
Auxin levels normally fluctuate throughout a plant’s life cycle, and these varying concentrations generally signal different responses in the plant, from initiating root growth to promoting flowering to, at high concentrations, abscission – the loss of a plant’s leaves. Synthetic auxins, such as 2,4-D can be used as a herbicide because it remains present in the plant cells at a high concentration for extended periods of time, rather than fluctuating as a normal, internal hormonal message would. As a result, these high concentrations induce abscission and eventually lead to plant death.
Consequently, this treatment is very effective at controlling weeds. However, because of the compounds volatile nature, nearby grape vines can also be affected. As a result, wineries must be mindful of how much herbicide they use and how often not only because of the environmental concerns related to herbicide use, but also because of the risk of losing one’s crop associated with it.
Whenever I read information about excessive use of certain molecules, I continuously think about homoestasis, equilibrium, and etc. In all the articles we have read in class, information we have gathered through tours, and life in general, it is important to live in a balanced manner. We continuously read articles about the overuse of mercury, licorice, and herbicides. All of these molecules can contain beneficial properties if used in a balanced manner.
ReplyDeleteI couldn't agree with you more. Moderation and balance in all things, whether it be herbicides, foods, even medications, tend to solve most problems. In my experience, at least.
ReplyDelete