Urea concentration on vegetative development and nutrition of Cactaceae epiphytic species

Abstract

Rhipsalis paradoxa, Rhipsalis baccifera and Hatiora salicornioides are epiphytic cacti from the Atlantic Forest. They have a great ornamental potential due to the exotic characteristic of their joints (stems segments). The study aimed to evaluate the growth and development of roots and shoots as well as macronutrient and micronutrient contents in the joints of these species fertilized with different concentrations of urea as a nitrogen source. The study also analyzed the importance of the root system on nitrogen absorption. Plants were weekly irrigated with modified Hoagland & Arnon solutions with 0, 16.7, 33.3, 49.9 or 66.6 mM N applied as urea. After 180 days of cultivation, plants were separated into joints and roots for biometric and biomass measures, as well as macronutrient and micronutrient analysis of joints. The experimental design was randomized blocks, with five treatments, four blocks and five plants per plot, for each species. Data were submitted to analyses of variance and regression. R. baccifera showed the highest plant length and number of joints in 29.94 and 40.82 mM N, respectively, H. salicornioides showed the highest length and number of joints in 48.29 and 45.68 mM N respectively. For R. paradoxa, the highest length was in 66.6 mM N. The lowest values for plant length and number of joints were observed in the absence of N, for all species. High nitrogen concentrations in the solution increased the N concentration in joints of R. baccifera, R. paradoxa and H. salicornioides by 24, 19 and 13 g N/kg dry mass, respectively. The roots of epiphytic cacti, besides the function of fixing the plant on substrate (phorophyte), are functional for nutrient absorption, and the best results were obtained in 30.05 to 66.60 mM N in the nutrient solution.

Rhipsalis baccifera cuttings growth with different cutting segment numbers and planting media

“…The root number on the cuttings will increase the absorption of nutrients in plants the better cutting growth. The levels of N, P, and K in Rhipsalis plants in sand media without treatment were 1.5, 0.59, and 6.2%, respectively [30]. Rhipsalis cuttings on rice rice-hull charcoal + chopped fern had the highest total N and K levels, namely 1.71 and 8.36%, compared to other treatments.…”

Nitrogen use efficiency as a tool to evaluate the development of ornamental cacti species

“…The excess is then stored as reserve (BENZING and RENFROW, 1974;CHAPIN, 1980;VAN WIJK et al, 2003;WINKLER and ZOTZ, 2009). Other studies have reported the occurrence of luxury consumption in Cactaceae species (NOBEL and DE LA BARREA, 2002;NOBEL and LA BARRERA, 2004;TAVARES et al, 2016).…”

“…Epiphytic Cactaceae species are marketed as vase plants that form an ornamental, exotic and dense mass of outstanding stems (SOUZA and LORENZI, 2000;ANDERSON, 2001;MENEGAES et al, 2015). Despite the obvious need, studies focusing on the growth and development of these species are scarce (SPURWAY and THOMAS, 1992;TAVARES et al, 2016). Suitable analytical tools to increase the knowledge of this group are also wanting.…”

“…These plants were fertilized with urea of N as the nutrient source, aiming to evaluate the use of N in biological processes. Thus, we asked if (1) nutritional efficiency indexes can be a tool to evaluate the physiological responses of ornamental cactus species and if (2) different species of ornamental cactus have different usage of N. Tavares et al (2016).…”

Biomass accumulation of Schlumbergera truncata (Haw.) Moran (Thanksgiving cactus) grown under high pot density

“…Regarding Schlumbergera truncata, little is known about its cultural requirements. Although this cactus does not have the typical requirements of most succulents, experimental work has been concentrated mainly on chemical issues (Araújo Rodrigues and Soares Queires, 2015;Tavares et al, 2016), photoperiod, and temperature manipulation (Nobel and Bobich, 2002), while other recommendations such as plant density during pot cropping are often based on the grower's experience. In general, to compensate for the low growth rate of each cactus cutting, Schlumbergera truncata growers include many phylloclades in each pot.…”