In 2017, the season started with a cool spring, but not quite as cool or wet as this spring. That year, I observed abnormal stem elongation in June that affected Superiors and a processing variety.
A colleague at North Carolina State University saw the same thing. It was clearly physiological, but the cause wasn’t obvious. We concluded that cool weather had this effect on a few varieties. The plants grew out of it in about ten days.
Yesterday, I found patches in a field of Superior with the same symptoms, just before I got chased out of the field by more rain. In 2017, the sprouts were elongated but green; this season, the stems are dark purplish-brown and the leaves are yellowish. This may be due to poor phosphorus uptake in cold soils. It could also be due to linuron damage. Gibberellic acid was not used on the seed.
I spoke with the grower yesterday, and we both expect that the Superiors will grow out of what is probably a physiological problem. I plan to monitor the field closely.
