one of the problems encountering gerbera production is the decreasing flower quality and yield especially when grown in non-standard greenhouse coditions. in this research the effect of weekly humic acid (ha) (500 mg/l) spray was studied and compared with application of 2 solutions containing 3.5 and 7 meq/l of calcium along with the same concentration of ha on gerbera jamesonii l. it was demon...
