Assessing drought stressed corn & silage

by | Aug 10, 2020 | 5 Ag Stories, News

With parts of Iowa experiencing extreme drought, agronomists throughout the state continue to monitor the corn crop.

West-central Iowa was downgraded to extreme drought conditions in the latest U.S. Drought Monitor, impacting 12 counties. It?s the first time D3 extreme drought has appeared in Iowa since the summer of 2018. During last week?s ISU Extension and Outreach drought webinar, Iowa Beef Center associate scientist Dr. Garland Dahlke presented how producers can assess their drought stressed corn and silage.

?The first thing is when to the pull the trigger, you know when it?s done and you give up on it? Dahlke said. ?When it?s brown it?s done. If you have a 200-bushel based yield and you start having this drought stress during tasseling and the leaf stage, you can see what it is per day of stress. Pollination is the critical time. If you have a week of bad stress during pollination, you may cut your yield in half right now.?

Dahlke said drought stress prior to pollination generally is not too detrimental to yield as long as rain comes later. One practice growers can conduct to assess their corn fields is what Dahlke calls the ?shake test.?

?If you are really gentle and you peel the husks off the cob, you will see that the silks are there,? he said. ?If the silks are still stuck on the plant, it means it hasn?t pollinated those kernels. That is a problem and those will not make it. If it does pollinate, the silks fall off easily and then they turn brown and you get your kernel. I guess you can kind of double check yourself to see what you do have expected out there.?

For more tips on assessing corn and silage impacted by drought, view Dahlke?s full presentation on the ISU Extension Crops Team?s YouTube channel.