During late season in some years and locations, observations have been that a complex of symptoms develop which can constitute some loss in yield potential and overall fiber quality in Pima and Acala cotton in the San Joaquin Valley of California.   Plant and soil samples have been repeatedly collected to evaluate nutrient status and presence of any specific diseases in many of the worst-impacted fields in recent years, and results will be described.  In locations where similar late season foliar and stem growth problems have been seen in multiple years, additional fruit load evaluations were done, and in some sites, more detailed foliar and soil fertilization was investigated in small plots.  Root evaluations were also done in some of the more severely impacted locations in efforts to define the most active parts of the root zone in late season.