Vapour-pressure deficit the plant may dry out and die. For this reason the ideal range for VPD in a greenhouse is from 0.45 kPa to 1.25 kPa, ideally sitting at around 0.85 kPa. As a general rule, most plants grow well at VPDs of between 0.8 and 0.95 kPa. In ecology, it is the difference between the actual water vapour pressure and the saturation water vapour pressure at a particular temperature. Unlike relative humidity, vapour-pressure deficit has a simple nearly straight-line relationship to the rate of evapotranspiration and other measures of evaporation. To compute the VPD, we need the ambient (greenhouse) air
What to the Slave Is the Fourth of July? under the sea, as well as on the earth. In the United States, the speech is widely taught in history and English classes in high school and college. American studies professor Andrew S. Bibby argues that because many of the editions produced for educational use are abridged, they often misrepresent Douglass's original through omission or editorial focus. The speech has been notably performed or read by important figures, including the following actors: What to the Slave Is the Fourth of July? "What to the Slave Is the Fourth of July?" is the title now given to a speech by Frederick