This study was done to investigate passive and active protective methods on reduction of losses from frost stresses in grapes cultivated in Shahrekord (Iran) during 2006 to 2008. Data analysis was done based on randomized block design, 3 replicates and five treatments including control without operate, Bordeaux mixture, increasing garden soil moisture up to field capacity, sprinkler irrigation upper grapes canopy, treatment by using heater between grapes canopy. Four measurements were done such as decrease of photosynthesis, increase of respiration, decrease of grapes yield, while cold stress in 2006 to 2007 and decrease of photosynthesis, increase of respiration, decrease of grape yield and tissue damages while freezing stress in 2007 to 2008 occurred at harvest time. Results showed that treatments using heaters were significant (P<0.001), the effective method in comparison to other applied methods during the first year because of no frozen stresses. Nevertheless, treatment of Bordeaux mixture was the best method (P<0.001) for reduction of damages on grapes within 2007 to 2008, since there was freezing stresses on growth of grapes.  

 

Key words: Frost damages, grapes, cold climate, cold stress and freezing stress.