Recent rains and overcast conditions have caused hardlock and boll rot in many fields. Both commonly appear when lower canopy bolls open during periods of rain or extremely high humidity and persisting cloudiness.
“Hardlock” occurs when a boll opens but remains damp and fails to fluff out normally. The locks of cotton remain as distinct, confined, wedge-like pieces within open burs rather than a pretty white mass of cotton fibers. With hardlock, all is not always lost.
Yes, these bolls often shatter as a picker passes through a field, leaving a trail of cotton on the ground alongside the stalks. However, with prolonged sunshine and good drying conditions, a few hardlock bolls may fluff enough to be grabbed by spindles and somehow find their way into the picker.
Boll rot is ugly. Numerous pathogens can attack bolls externally and internally. Some discolor the entire boll and cause a complete loss. Some effect interior portions and can result in total or partial loss of the boll.
Fungicides are ineffective in curbing boll rot. Insect damage, particular stink bug feeding, worsens the occurrence of rot. If you notice a boll with tan, discolored bracts, expect to see internal rot.
There is no cure for hardlock and boll rot, though sunshine and wind can check the spread. Canopy management, which, of course, involves good PGR use, proper fertility, and row and plant spacings, can influence the severity of these late season problems.
On a positive note, the fact that boll rot is present often means the cotton has experienced good conditions, has good canopy growth, and has good yield potential in spite of lost bolls.