Thus, when people hypoventilate (i.e. causing an increase in CO2) this causes the pH in your blood to decrease, making it more acidic. (and when hyperventilation occurs, O2 is increased, which causes an increase in pH - making blood more basic).
Pre-emergent applications should be made when soil temperature are still below 50 for the best prevention of crabgrass. Pre-emergent applications are not recommended for areas where new grass seed is going to be planted during the first half of the growing season.
The key is the timing. Pre-emergent herbicides MUST be applied BEFORE crabgrass seed germinate. If Bob and other lawn owners choose one of the products above and put it out on March 1, 2004. I think summer crabgrass control will be much better.hat I found shocked me! The data show that soil temperatures reached 52 degrees F. on Feb. 24 in 2000, Feb. 25 in 2001, Mar. 14 in 2002 and Mar. 4 in 2003. My timing advice has been wrong ! To get good crabgrass control in Atlanta you should apply the pre-emergent on March 1, not March 15.