GROWTH AND NUTRITION OF Paratecoma peroba SEEDLINGS IN DIFFERENT TUBE VOLUMES AND CONTROLLED-RELEASE FERTILIZERS

Abstract

Paratecoma peroba is a native forest species of great economic and ecological interest, currently at risk of extinction from selective and illegal exploitation; however, there are no established parameters for the production of seedlings of this species. The objective of this study was to analyze the growth and nutritional balance of P. peroba seedlings grown in polypropylene tubes of different sizes with variable doses of controlled-release fertilizer (CRF). Three volumes of tubes (120, 180, and 280 cm3), four CRF doses (0, 2.5, 5, and 7.5 kg m-3), and a conventional mineral fertilizer (CF) were tested as indicated in the literature for native forest species: arranged in a completely randomized design in a 3 × 5 factorial scheme, with four replicates composed of 16 seedlings. After 180 days, the percentage of survival, growth variables, indices of the diagnosis and recommendation integrated system, and the average nutrient balance index of the seedlings were analyzed. Based on the total dry matter and the mean nutritional balance index, the combination of a 280 cm³ tube with a 7.5 kg m-3 CRF dose was the most effective in the production of P. peroba seedlings.

New compostable tubes for the production of high quality seedlings of three species of Mimosa spp

“…the growth in height and diameter obtained in the three evaluations (Table 1 and Figure 1). The higher values of height and diameter observed in the 110 cm 3 tube compared to the 55 cm 3 tube reinforce results that point to better development of the root system in larger containers since there is more space for roots to distribute and more nutrients available for absorption by seedlings (Feletti et al 2020). However, the efficiency of the 58 cm 3 SISBGC tube (which is sometimes comparable to the 110 cm 3 tube in this study about the diameter and height values obtained for M. micropteris and M. incana, respectively) demonstrates that not only is the volume of the container important for adequate development of the root system, but the container morphology could also lead to quality seedlings in the nursery since the quality of the root system is related to the adequate stem development.…”

“…It is assumed that the proper development of the root system, in turn, influences not only the performance of the seedling in the nursery but mainly in the field and can ensure higher survival, which is particularly important if the planting occurs in drier times when water supply becomes the most influential factor for seedling survival in the first year after planting (Grossnickle 2016). Finally, although larger containers are often associated with better seedling development (Pias et al 2015), they present disadvantages such as lower production per unit area and higher consumption of substrate and fertilizers, which are not as costly when using smaller containers (Feletti et al 2020). For biodegradable packaging, costs are reduced since tubes do not need to be disinfected to be reused, as well as because seedlings do not need to be dispatched from them, and less human resources to remove the seedlings from the plastic tubes and prepare them for the expedition is required.…”

“…In fact, the root system is so crucial that several studies have pointed out that regardless of the species evaluated, RDB is the variable that most influences the other variables and DQI, constituting the leading indicator of seedling quality (Rossa et al 2013, Grossnickle andEl-Kassaby 2016). Other research has also frequently found that although seedlings produced in larger packages have significantly higher heights in the nursery, this difference dissipates within a few months after planting, and seedling growth mainly depends on the quality of the root system (Feletti et al 2020, Cabreira et al 2021. With well-formed root systems, seedlings more efficiently absorb the nutrients made available during planting, and smaller seedlings gradually reach the larger seedlings.…”