Growth analysis on rose flowering stem cv. 'Charlotte' in both soil and substrate cultivation systems

The rose is a perennial plant, whereby stems may be found at various stages of vegetative growth and flowering before harvest. Some rose growers had recently been using a soilless crop system in the Bogota plateau. The aim of this study was to generate mathematical growth curves over time and determine different growth indexes of rose flowering stalk when growing in different substrates and soil. Four growth indices were evaluated on the flowering stems of rose (Rosa spp.) cv. 'Charlotte' grafted on 'Natal briar' and planted under greenhouse conditions in the Bogota plateau. Burned rice husk, and the following mixtures: 65% burned rice husk - 35% coconut fiber; 35% burned rice husk - 65% coconut fiber; coconut fiber or loamy soil were used as substrates. The growth indices evaluated were crop growth rate, leaf area index, relative growth rate, and net assimilation rate, which were obtained from measuring dry mass and leaf area at 8 different developmental stages. Coconut fiber plants were statistically faster in the duration of evaluated stages than the ones in 35% burned rice husk treatment. Total and foliar dry mass of flowering stems didn't have statistically significant differences among the treatments. Nevertheless, in 35% burned rice husk, a higher accumulation of total and foliar dry mass and a higher net assimilation rate were observed. Excepting 35% burned rice husk, the rest of the treatments made their optimum leaf area index between 50 and 60 days after pinch. Flowering stems in burned rice husk as in coconut fiber showed trends that contrast with one another in net assimilation rate. The composition of substrates influenced the duration of development cycle of flowering stem. Crop growth rate was accelerated when plants were grown in burned rice husk compared to plants in substrates with coconut fiber content.