The most important difficulty that the producers have been found to adopt the cultivation in plastic greenhouses is the lack of specific data on the rational use of the water and informations about when and how much water apply. This research was developed in a farm in Paranapanema - SP, Brazil, with tradition in pot chrysanthemum grow. The main objective was to identify the soil water tension that could result in better commercial quality of chrysanthemum Rage, cultivated in pot and maintained in greenhouse. The treatments were defined for six levels of substrate water tension: -2; -3; -4; -6; -10 and -30 kPa. The irrigation time was defined for each tension and also the equivalent height int the mercury column of the tensiometers. The obtained results showed that the cultivar Rage obtained the largest percentage of vases of high quality (A1) in the treatment irrigated with the soil water tension of -4 kPa. The irrigated treatment when -30 kPa was reached resulted in the smallest percentage of vases A1.
Dendranthema grandiflora; substrate water tension; pot
