It’s Been Wet, But Don’t Let Moisture Stress Creep Up On You
DR. JOE HENGGELER
PORTAGEVILLE, MO.
It’s been so wet lately that irrigation is probably the last thing on our mind. However, be on your guard against moisture stress creeping up on you!
If the soil in the top portion of the profile has constantly been wetted by frequent rainfall and/or sprinkler irrigation, deep roots do not develop. Should then the supply of moisture be suddenly curtailed, and a period of high ET demand occurs, plants can suddenly become drought stressed, as happened back in 2011. In that year monthly precipitation in March and April averaged 8 inches each month, after which rainfall in May through August averaged less than 1 ½ per month. Driving by those fields I thought they had been burned down with a herbicide application until I finally figured out the real reason.
I actually saw the same phenomenon occur many years ago when I visited the emerald isle, Ireland. It had been raining as usual before I got there, but during my 2-week visit the rare occasion of no rain occurred. The tops of the hillsides started turning brown from drought stress, something that rarely occurs in Ireland!
Andrea Jones of the Delta Center reported last Thursday, the 11th that she has been using the Woodruff chart to schedule irrigation on corn and it was showing that she didn’t need to irrigate. The chart indicated that she didn’t need to irrigate until Tuesday, the 16th. However, the corn was stressed and “pineapple topped” the day before (the 10th), so she wisely irrigated, even though the charts told her to wait for almost another week.
Don’t get lulled to sleep – have your irrigation systems ready to be turned on and then try to apply a small irrigation amount. ∆
DR. JOE HENGGELER: Irrigation Specialist, University of Missouri