The air

by M. Arjoca,

FogIt's the fifth important element in the plants life, its quality putting a stamp on plants growth and development. You don't want a garden in a polluted air near a plant, a factory or a work which emanates toxic gases. For example the burning of coals and fuel emits many polluting substances: sulfur dioxide, nitrogen oxides, nitrite, nitrate, hydrocarbons, ozone, peroxyacetyl nitrate, substances which the plants can absorb through their leaves, stalks or roots. These pollutants, in some concentrations affect the growth and development of plants, facilitate the diseases and pests and cause the decrease of yield. Some times the plants die. Plus they are toxic for men too.

The symptoms of pollution on plants can be: discoloration of the leaves or their coloration from black to white, flecks and spots, curly leaves and sprouts, necrosis, inhibition of growth, the fall of leaves and flower buds etc.

For example, the ozone causes on bean the yellowing of the upper side of leaves, tissue necrosis, reddish-brown coloration.

Another aspect about air is its temperature. The temperature varies from a climate zone to another, from season to season, from day to night and even from a field to another.

There are arid zones or rainy zones, with high or very low temperatures, zones with many rains but with medium or high temperatures. There are zones where in the summer the temperatures are high and in the winter are very low. In some zones the summers are not too hot and the winters are mild. There are zones where is warm all year or is cold all year.

In some areas the range of temperature varies very much from day to night. For example, in deserts the temperature can rise to 45° C during the day, but in the night can lower below 0° C.

The temperature varies not only at global level but even from field to field, depending on their position and orientation. The gardens located on the south side have higher temperatures than the gardens on the north side.

Garlic under snowThe temperature has an important role because the germination, the growth, the development, the blossoming and the fructification of plants accomplish only if it reaches a certain value.

Also the very low or very high temperatures and the rapid oscillation from very high to very low values can cause the death of plants or the damage of different tissues (burns, blackness, discoloration, the fall of flowers, buds and leaves etc.). The tomatoes, for example, can not resist below 4° C.

The watering must be done in the morning or in the evening and not during the day, when the temperature is high and passing from hot air to cold water can damage the plants.

Plus there are plants which prefer higher values and plants which prefer lower values. The peppers love high temperatures, around 30° C (at low values can not blossom), but the pea and the potatoes prefer low temperatures. The sunflower and the garlic resist even below 0° C.

Here are some vegetables and their preferences.

Prefer high temperatures
Prefer moderate temperatures
Bean Beat
Corn Broccoli
Cucumbers Cauliflower
Eggplants Celery
Melons Garlic
Peppers Onion
Pumpkins (squashes) Parsnip
Soy Pea
Tomatoes Radishes
Watermelon Spinach

To have some control on the temperature and to protect your plants you can do these things:

Willow branch broken by windThe wind is another important element. It can make real damages on plants, breaking the leaves and branches or pulling them out from ground. Sometimes it has a devastating erosion effect on soil. The wind makes the water evaporate faster and can cause the dehydration of plants because they don't have enough time to absorb the water they need. The effects are worse when the wind is combined with strong rain, hail or snow. Cold winds inhibit the growth of plants.

The plants must be protected by strong winds. So you have to see how often and strong blows the wind on the field or the place you want a garden. The walls, buildings, fences, bushes can protect from winds. Many farmers have around their farms windbreaks from trees, shrubs and berms.

Green fences, wood or wire fences on which the plants can climb are efficient. You can also arrange the tallest plants so they can protect the short ones. Alternate the rows with tall plants with the rows with short plants. Choose native plants which are adapted to the local environment. Make berms from place to place to protect the neighboring plants. Use protective sheets.

More about:

Plants that purify the air