Journal of Applied Horticulture. 2002: 4(1): 56-59

Performance of gerbera (Gerbera jamesonii) cultivars under fan and pad cooled greenhouse environments

Singh, K P; Mandhar, S C

Indian Institute of Horticultural Research, Bangalore, Karnataka - 560 089, India.

The performance of 9 exotic cultivars of gerbera (G. jamesonii) (Diablo, Lyonella, Ornella, Sunset, Tara, Thalassa and Tiramisu, Twiggy and Whitsun) was studied under fan and pad cooled greenhouse environments at the Indian Institute of Horticulture Research, Bangalore, Karnataka, India from July 1998 to June 1999. The greatest plant height (48.83 cm), and number of suckers (5.16) and leaves (46.27) per plant were obtained with Tiramisu, Lyonella and Ornella, respectively, while the lowest values of the aforementioned parameters were recorded for Whitsun (47.88 cm), Sunset (3.82) and Tiramisu (26.74), respectively. Flowering was earliest (47.88 and 57.47 days for 50 and 100% flowering, respectively) in Whitsun and latest (83.10 and 88.30 days) in Tiramisu. The greatest diameter of flower (10.70 cm) and length of flower stalk (58.27 cm) were recorded for Tiramisu and Lyonella, respectively. The thickest (0.70 cm diameter) and heaviest (22.20 g) flower stalks were observed in Twiggy, whereas the thinnest (0.60 cm diameter) and lightest (13.94) stalks were observed in Whitsun. The highest total number of flowers produced per plot in a year, and the mean number of flowers per plant and per month in a year were obtained with Ornella (1058.00, 47.26 and 5.02, respectively), followed by Thalassa (988.00, 44.52 and 4.61), whereas the lowest were obtained with Tara (591.33, 29.48 and 2.82), followed by Sunset (600.00, 31.15 and 3.11). The percentage of 1st grade flowers was highest in Lyonella (73.85), Sunset (70.41) and Tiramisu (70.54), and lowest in Tara (47.16) and Thalassa (47.87). The highest percentage of discard flowers was recorded for Thalassa (37.30), followed by Whitsun (20.47). Based on the overall performance, Lyonella, Ornella, Tiramisu and Twiggy are recommended for commercial cultivation. The temperature inside the greenhouse could be controlled from 24.7 to 30.5 degrees C when the ambient temperature varied from 27.4 to 35.5 degrees C. The lowest temperatures of 8.0 and 6.7 degrees C were recorded during April and March, respectively. The RH in the greenhouse varied from 44 to 77%, while the outside RH ranged from 20 to 67% when the rate of ventilation was 1018 cubic meter per minute.