Picture Banner for SECC K12 Site

Humidity relation to agriculture/K-12

How does this relate to agriculture? 

Humidity, as you know if you are an “outdoorsy” person, can have a great effect upon human health.  As most growers work outside during the hottest part of the day, they need to take extra care to stay hydrated when temperature and humidity are high.  People keep cool by perspiring. 

A pint of blueberries
Figure C

If the humidity is high, this moisture doesn’t evaporate from your body very fast.  In areas that are very dry, such as Arizona, the humidity is so low that when you sweat the water evaporates so quickly that you don’t even feel it.  In this case, you must be careful to stay hydrated because the water loss goes unnoticed.

Humidity can also affect plant turgor pressure, which is an indicator of the amount of water in plant cells.  When humidity is low, and dew points are in the 50s and low 60s, moisture evaporates from plants very quickly.  When this happens, plants can wilt rapidly if too much water is pulled out of plant cells through transpiration. Conversely, when humidity and temperature are both high, plants can get overheated because transpiration is reduced, thus restricting evaporative cooling. 

Humidity also influences plant diseases, especially fungi and molds that grow and spread rapidly when humidity is high. Humidity can also affect the fruit set of some plant species.  An example is the bean (Phaseolus spp.), which has been shown to respond negatively to low humidity during fruit set.

Humidity is also an important consideration for post-harvest storage of crops.  Cold temperature and low humidity are important for the long-term storage of grains (corn, wheat etc).  Conversely, fleshy vegetables and fruits (apples, cucumbers) need to be stored in cold temperatures and high humidity in order to prevent water loss from the fruit that results in shriveling.

Last modified date: Friday, November 5, 2010 - 1:19pm