Plant Growth Control by Lucy Liu

    A lot of plants have purposes for human use. Some of them produce fruit or medicine though different part of the plant, some of them have fibre that people could make fabrics from that, and some of them are just an very important part for landscape and  virescence. In many situations, we need fresh flowers or fruits in a certain period of time, for example, people are most likely to buy poinsettias Around Christmas, and every year there would be a huge demand for fresh rose in Valentine’s day. That makes the plant growth control become extremely important for growers.

    In order to have the plants ready at the right stage of growth on time, temperature control is necessary. Different species of plants have different range of required temperature, as a general rule, when the temp is a little higher than the requirement, the plant is going to grow faster, and for lower temperature, the plant would grow slower or even stop to grow. So if you would like your plant to flower a week after its normal flowering time, it’s good to turn down the temperature a little bit, however, not too much so your plant would not be killed by the cold environment. Another important part for growth control is the lighting. Plants can usually decided to two parts: long day plants and short day plants. For long day plants, they are able to flower when day length is as long or longer than the critical day length. Accordingly the short day plants are the ones that would produce flowers only when day length is shorter than a critical length. In that case, if the merchants want to buy flowering plants in certain height range, the growers could let the plants grow until the height and make them flower by changing the lighting of their greenhouses. Take poinsettia as an example. Poinsettias are short day plants which means it would be flowering only when they receive short day light. In the horticulture lab, we grew the poinsettias in the greenhouses with long day lighting environment and let them get stronger and bigger but not flowered, and since last week we changed the lighting to short day for the plants so that they could start producing flowers and then they will be ready for the Christmas.

   Plant growth control is very magic and it also can bring conveniences to our life. I’m enjoy learning that in my lessons and that makes me look forward to learn more about this field.