Irrigation information is provided in this article for corn, including amounts to apply during the reproductive stages. Typically, corn will produce tassels about 60 days after emergence and it takes about 60 more days to go from silking to black layer or physiological maturity. Water needs increase dramatically through the grain fill period and taper off closer to black layer. There are scheduler programs from UT (MOIST) and other universities that can be helpful in determining how much water to add each week depending on the planting date and anticipated maturity of a hybrid. The amounts indicated below are ballpark amounts based on some information from Pioneer that should keep the crop from being deficient. Plant growth and days after planting may differ from this chart based on days to emergence and average temperature conditions. With the continued dry weather and scattered showers, if you haven’t turned the pivots on please do so now. The important take home message is to start early enough in the season to avoid getting behind on watering the crop to take full advantage of the benefits of irrigation.
| Days After Planting | Growth Stage/Plant Height |
Inches per Day |
Inches per Week |
| 0-20 | seedling |
0.06 |
0.42” |
| 20-30 | 5”-10” |
0.09 |
0.56” |
| 30-40 | 10”-20” |
0.15 |
1” |
| 40-50 | 20”-50” |
0.20 |
1.4” |
| 50-60 | 50”-80” |
0.21 |
1.5” |
| 60-70 | 80”-silking |
0.25 |
1.75” |
| 70-100 | Early to mid grainfill |
0.33 |
2.3” |
| 100-110 | Late Grainfill |
0.25 |
1.75” |
| 110-120 | To Maturity or Black Layer |
0.23 |
1.6” |
My supplier has been tissue sampling my corn @ the V8 stage. The lab tests indicate all of my corn is deficient in boron & a foliar application is recommended. I am skeptical of the necessity of this input. Is boron deficiency common in corn @ this growth stage? I included 1#/ac of boron in my dry fertilizer applied prior to planting. Thanks for your help.
Richard,
In a typical spring and under irrigated conditions, your soil applied boron should be adequate to meet the needs of the crop during the season. With the dry spring we are having, I think uptake from soil is less than normal and in dryland corn in particular we may see these temporary drops in foliar levels. A good rain this week would really help with soil uptake. A foliar app wouldn’t hurt the crop at this point but it is lack of water causing issues and one shot of a microntrient won’t correct for a water deficiency.
Your comments are just a reminder that plants do not uptake boron except by foliar application.
Nick,
Plants will obtain boron through root uptake. Foliar applications may help in deficiency situations where we can’t physically correct soil levels.