Articles
NUTRITION AND POST-PRODUCTION PERFORMANCE OF PHALAENOPSIS POT PLANTS (REFEREED)
The plants were grown in peat substrate and supplied with 150, 275, 400, 525 or 650 mg N per plant from a soluble fertilizer (N : P : K = 16 : 4 : 18). For all three cultivars increasing fertilization rates resulted in larger plants.
Very small differences in plant diameter between the highest rates, however, indicated already beginning luxury consumption.
Plants given higher fertilizer levels developed significantly more inflorescences and flowers than those from lower ones.
Branching of the inflorescences was promoted by higher nutrient supply.
The three cultivars differed in their response regarding the optimum of nutrient supply.
For ‘Abylos’, no clear optimum level appeared, for even the highest rate brought about a significant additional increase in most of the recorded characteristics.
For the two other cultivars ‘Sylba’ and ‘Nopsya’, however, 525 mg N per plant proved to be enough.
In these cultivars, especially in ‘Sylba’, a very high nutrient supply also resulted in inferior plant quality.
Plants, which had received the two highest rates, developed large weak leaves and flabby flowers.
Partly flower development ceased shortly before opening.
The flowers remained in the stage of large buds until they finally began to fade directly.
The reaction of the hybrids ‘Sylba’ and ‘Abylos’ in the post-production trial followed a similar trend as described above regarding the optimum supply.
For plants of ‘Abylos’ the period of full flowering, characterized by over 50 % of open flowers, lasted four to six weeks longer at the three highest fertilization levels than at the two lower ones.
For ‘Sylba’, however, this period decreased clearly from thirteen to six weeks by increasing the supply from 150 to 400 mg N per plant.
At the two highest rates, the 50 % – level could not be exceeded during the whole experiment.
Only 40 – 50 % of the flowers were open for three or two weeks.
During the production of optimal fertilized plants levels of nutrients in the substrate increased, which should be taken into account for correct interpretation of analyzed values.