Growth, developmental features and flower production of Anthurium andreanum Lind. in tropical conditions

Anthurium cultivation is becoming very important in global cut flowers production. Soilless and protected cultivation have been developed for 20 years in tropical countries in order to improve yields and flowers quality and to reduce phytosanitary problems, but the different parameters that govern flower formation are poorly understood. Particularly, a better understanding of plant structure and functioning is needed to explain yield components. Young tissue-cultured plants have first a monopodial growth which corresponds to the juvenile and vegetative phase. After this, the plants have a sympodial phase, with a flower produced for each leaf. The time separating the emergence of two aerial organs and the size of these organs were measured. Accumulated day degrees, with a threshold of 14 degreesC, from planting to first flowering were 2143 degreesC days (219 days). The apparent phyllochron decreased during the monopodial phase from 680 to 280 degreesC days (14 T threshold) and increased quite regularly in the beginning of the sympodial phase from 330 degreesC days for the first leaf to 615 degreesC days for the seventh leaf. This seemed to represent a threshold for the phyllochron; it varied less for the next leaves. The size of the leaves and flowers increased from the first to the seventh leaf of the sympodial phase and to the seventh flower. The size of the peduncle and spathe of the first-formed flowers are too small to be sold in the best quality categories. It might be possible to make large flowers appear earlier by suppressing small flowers as soon as they emerge. On the other hand, the suppression of the young leaf, i.e. the strongest sink in the plant, can accelerate the emergence of the next flower, but it reduces the leaf area, and hence the amount of assimilate for subsequent flowers. (C) 2003 Elsevier Science B.V. All rights reserved.