What a difference a year makes! There may be a few pocket droughts developing, most very tiny. Last year it was widespread drought and heat with pocket good spots!
Brian Downing, an agronomist with Stewart Seeds, says there is a wide range of growth stages of corn in his area. Some is tasseling in southern Kentucky, and probably nearing that stage in northern Indiana. Somewhere in between, with corn just passing V2 or V3 and not yet to V5, are a few wet pockets in southeastern Indiana.
While corn is growing from V7 to V18, or basically from shortly after the growing point is above ground to tasseling, it's important for it to not have a bad day, the agronomist says. Every day was bad in 2012!
Consumption of nitrogen ramps up during this grand growth phase. Proper and adequate nitrogen levels are important. Adequate levels of phosphorus and potassium are also important. A deficiency of phosphorus results in purpling, although except in rare cases, it is seldom seen at this time of year because most Indiana soils have adequate phosphorus.
Potassium can be a different story. Some soils are borderline on potassium. Look for brown edges on leaves as signs of K deficiency in the plant. If nitrogen is short, the yellowing will begin at the tip and move up the midrib. Severely deficient plants starved for nitrogen will be yellow and stunted.
While this problem is not expected to be widespread there could be some issues with nitrogen during the season in areas where the N was applied early and then heavy rains caused excessive loss.
Kernel row determination will be complete around the V12 stage, the agronomist says. Much of it is based on genetics, but as farmers found out last year, environment can affect it. Last year it was a negative effect, although it can also be a positive effect in very good conditions.