Does wind actually produce any chemical effect within the plant? Yes. It has been studied and concluded that movement of plant stems and branches either caused by wind or other sources will stimulate the production of ethylene within the plant.
The hormone ethylene is widely considered to help cause aging or maturity in a plant due to its role in accelerating such developmental processes as ripening, senescence, and abscission (the process where the plant loses its leaves or fruit). Ethylene also regulates many aspects of growth and development throughout the plant’s entire life cycle.
Ok, but does this strengthen stems? Plants produce and use hormones much the same way that animals do—to help adapt to and survive the environment they live in. In this case, moderate movement can produce ethylene inside the plant, altering growth patterns to create sturdier stems or trunks.
Hormones known as auxins are also produced within a plant when subjected to mechanical stress; indole acetic acid is one of these. You may notice plants grow toward light. Auxins produced at a greater level on the shaded side of the plant cause the growth on that side to accelerate, resulting in the plant leaning toward the light.
We want the primary stems or trunks of our plants to be strong. With plants that are notorious for having very pliant bases like indeterminate tomatoes or vines, we have them grow onto a trellis or other similar support. If our crops haven’t the strength to stay upright, they may fail to get the appropriate light or the fruit can be damaged by winding up on the soil where insects can attack.
Some trees have this same propensity. For example, when grown for nursery retail, the California pepper tree is given a stake on which to grow tall to help make it more attractive for purchase. This early focus on height can later become a problem when growing in the landscape as the tree tends to bend and be too pliant.
Staking is done in the attempt to overcome this, but if the staking does not allow wind to cause bending, thus challenging the tree to develop some rigidity, the tree will remain floppy. Proper staking should never hold the plant rigid.
In hydroponics, we want our plants to have sturdy stems at the base to properly support the plant as it grows and develops fruit. Wind is an easily used source of the movement needed to produce a small amount of ethylene or an auxin and helps our plants to be adequately strong.
However, strength is not our only goal and it’s not the most important. We want yield. Too much wind will cause the plant to grow in a manner that does not support this goal. Yet, sometimes we are dealing with plants that won’t stand up correctly and may have trouble getting all the light or radiation that we provide. What to do?
Having leaves gently move as a response to soft breezes in the grow area or grow tent, especially while the plant is young, will generally produce a strong and vigorous plant with a sturdier base. Blasting plants, whether young or mature, with strong wind is going to interfere with crop production.
Strong winds will also tend to cause the stomata on the plant leaves to close, reducing CO2 intake and weakening photosynthesis. Photosynthesis is a critical process for nearly every aspect of plant health and production. Though young plants often develop properly without these gentle breezes, dealing with at least mild wind is natural for most plants.
Those that are completely protected and isolated from any movement or breeze at all have an increased propensity to develop some weakness in their stems or base. Hormones produced by this movement will affect other aspects within a plant, too.
A recommendation for supplying a periodic gentle breeze for your hydroponic crop can help increase the odds of more normal strength of growth and plant vigor. It is to be noted that the grower needs to thoroughly understand the differences between mild beneficial wind stimulation to the stem or trunk and the more severe stress associated with heavy and frequent wind or any other form of mechanical movement.
Hormones like auxins and ethylene are responsible for managing various growth aspects for our crops. Ethylene is also used by growers to help ripen fruits. The presence of ethylene during the mature state of the fruit will help increase sugars while reducing acid. We’ve all tasted fruit that has not had time to ripen. Bananas turn yellow during this process and you’ve probably noticed how much sweeter they get.
Mechanical movement will trigger responses in the production of this process. Using synthetic breezes when growing in a windless hydroponic environment can help to maintain an adequate level of both. Using wind early in a very diminished and controlled way can help get your crop started in the right direction.
Periodic controlled breezes can produce a few other benefits. In a hydroponic grow without adequate air circulation, humidity can run high. As a result, moisture accumulates on the leaves and buds, and this can be the cause for mildew and other molds to begin to proliferate.
Mild breezes, along with controlled humidity levels, will help evaporation keep mold from growing. If ventilation from outside your grow area is your technique for keeping the air inside dryer, making sure fungal spores and insects are not entering your controlled grow area is vital. Employing filters capable of trapping these spores or pests can eliminate the problem.
However, if you notice a plant has become infected, your beneficial breeze can turn against you by helping move the mildew spores and other pests from one plant to another. Plenty of room between plants will help reduce this likelihood, but infected plants should be removed, cleaned, and treated as quickly as possible to avoid an outbreak. Routine inspection of your crop is vital towards catching problems early and keeping them manageable.
Along with using a mild wind in your grow area to help keep disease down and plant sturdiness at an adequate level by producing normal amounts of hormones, use thorough care and overall good maintenance practices to maximize your crop’s success. Provide controlled temperatures and ventilate your greenhouse or grow tent to prevent high humidity conditions.
This may require some extra venting early in the day when moisture may have condensed. You most likely will not need wind at all times, and using a dehumidifier can certainly help keep gray mold or mildew down.