NITROGEN IN THE INITIAL GROWTH AND PHOTOSYNTHESIS PHOTOCHEMICAL IN Alibertia sessilis (Vell.) K. Schum

Abstract

The use of N fertilizers can contribute to seedling production in native species, such as Alibertia sessilis (Vell.) K. Schum, a fruit plant of the Cerrado ecoregion. Considering that there are few studies on mineral nutrition for this species, the aim of this study was to evaluate the effect of N on the growth and photosynthesis photochemical of A. sessilis. The experiment was carried out in plastic pots in a greenhouse with five N (urea) concentrations: 0, 25, 50, 75, and 100 mg kg-1. The experimental design used was a randomized block design with four repetitions. At day 180 after transplantation, morphometric and photochemical characteristics, including biomass and seedling quality, were evaluated. Seedling survival, the stem diameter of the harvest, and the height/diameter ratio were not influenced by N. The maximum height was 14.38 cm with 54.2 kg-1 N. The greatest number of leaves and value of the chlorophyll index were found in seedlings produced with maximum doses of N. The photochemical characteristics of photosynthesis, except initial fluorescence, were positively influenced with N concentrations between 60-85 mg kg-1 N. The largest fresh leaf and stem biomass was 2.391 and 0.257 g plant-1 with 54.0 and 33.0 mg kg-1 of N, respectively. The multivariate analysis of the major components explained 79.81% of the remaining data variability. The seedlings of A. sessilis responded positively during the initial growth phase, reflected in their biomass, with N concentrations close to 50.0 mg kg-1.

Ascophyllum nodosum seaweed extract and mineral nitrogen in Alibertia edulis seedlings

“…This higher value can be associated with the increased capacity of the plant to absorb more nutrients from the soil in the presence of ANE, this being especially beneficial in terms of height and canopy exposure, therefore allowing greater efficiency of light absorption and conversion into chemical energy for photosynthetic metabolism, resulting in * -Significant at p ≤ 0.05 by F test; Equal letters in each dose of ANE do not differ statistically regarding mineral N at p > 0.05 by F test an increased nutrient demand. A higher chlorophyll index is associated with a larger leaf area, which provides better conditions for photosynthetic conversion and increased production of photoassimilates for leaf expansion (Santos et al, 2020c).…”

“…This was performed in the morning period until dripping point (10 mL per plant, based on pre-test), every 30 days, from 20-200 days after transplanting (DAT). The addition of 50 mg kg -1 of mineral N directly to the soil (based on the work of Santos et al, 2020c) was performed at 30 DAT, using urea (45% N) as a source, diluting the amount of N in distilled water, and adding around the collar of the seedlings.…”

“…In addition, N is used in other metabolic processes (Faria et al, 2020) and improves seedling nutrition and growth. This is especially important considering that native species generally exhibit slow initial growth (Santos et al, 2020c).…”

Ascophyllum nodosum seaweed extract in Inga edulis seedlings under drought and the potential of phenotypic plasticity

“…The positive response of seedlings to the application of ANE is due to the enrichment of N, which favors vegetative growth (Santos et al 2020) and the contents of P, K, Ca, which act on the structure of plant tissue and biomass production (Costa et al 2020;Rodrigues Neto et al 2021). Thus, these elements acting together increased the development of LA, DQI, chlorophyll index, F v /F m and proline content in I.…”