EFFECT OF NURSERY ENVIRONMENTAL CONDITION AND DIFFERENT CULTIVARS ON SURVIVAL RATE OF GRAFTED TOMATO SEEDLING

This study was conducted in order to improve survival rate of grafted tomato seedlings by controlling nursery environment during the healing and acclimatization processes. Twelve combinations of four temperature levels (17°C, 20°C, 23°C, and 26°C) and three relative humidity levels (70%, 80%, and 90%) were set up in order to evaluate influence of relative humidity and temperature on the survival rate of grafted tomato. When optimal environmental condition was selected, different cultivars were carried out to examine the influence of different scions and rootstocks on the survival rate of grafted tomato. The survival rate increased with increasing temperature from 17 to 23°C in all humidity levels on the 3rd and 7th day after grafting. However, the survival rate significant decreased with increasing temperature to 26°C. Increasing relative humidity significantly increased percentage of diseased plants. The highest survival rate (88.2%) was observed at 23°C with 80% relative humidity. There was no significant different among scions with survival rate on the 3rd day after grafting but significant different among scions with survival rate on the 7th day. The higher diseased plants were observed in cherry tomato group compared other groups. There was significant different among rootstocks with survival rates on the 3rd day after grafting but not significant different among rootstocks on the 7th day and final survival rate.