The effects of organic and chemical fertilizers on yield and yield components of safflower (Carthamus tinctorius L.) under water stress conditions

In order to investigate the effects of organic and chemical fertilizers on yield and yield components of safflower (Carthamus tinctorius L.); Goldasht variety under water stress conditions، an experiment was conducted on research farm، Faculty of agriculture، Shahid Bahonar University of Kerman، in split plot with Randomize Block Design (RCBD); and 3 replications in each treatment. Water stress in three levels: 60 mm evaporation from evaporation pan (normal irrigation); 120 mm evaporation from evaporation pan (low water stress); 180 mm evaporation from evaporation pan (high water stress) in main plots and cow manure (15 t/ha); humic acid (80 kg/ha); chemical fertilizer (N=150 kg/ha، P=50 kg/ha، K=100 kg/ha)، and control (no fertilizer) were in sub plots. The reasults showed that water stress caused decrease in leaves، Relative Water Content (RWC)، yield، yield components and harvest index (HI); but increased chlorophyll meter numbers (SPAD). The effect of fertilizer was positively significant on all indices; except on 1000 seed weight. Cow manure increased seed yield significantly، and had positively significant effects on other indexes. It seems that organic fertilizer، specially cow manure in water stress condition، caused higher soil water content; and finally higher yield، compared to chemical fertilizer; and is better choice in water stress condition.