Morpho-Physiological Responses of Pisum sativum L. to Different Light-Emitting Diode (LED) Light Spectra in Combination with Biochar Amendment

Abstract

Light quality and nutrient availability are the primary factors that influence plant growth and development. In a research context of improving indoor plant cultivation while lowering environmental impact practices, we investigated the effect of different light spectra, three provided by light-emitting diodes (LEDs), and one by a fluorescent lamp, on the morpho-physiology of Pisum sativum L. seedlings grown in the presence/absence of biochar. We found that all morpho-physiological traits are sensitive to changes in the red-to-far-red light (R:FR) ratio related to the light spectra used. In particular, seedlings that were grown with a LED type characterized by the lowest R:FR ratio (~2.7; AP67), showed good plant development, both above- and belowground, especially when biochar was present. Biochar alone did not affect the physiological traits, which were influenced by the interplay with lighting type. AP67 LED type had a negative impact only on leaf fluorescence emission in light conditions, which was further exacerbated by the addition of biochar to the growing media. However, we found that the combination of biochar with a specific optimal light spectrum may have a synergetic effect enhancing pea seedling physiological performances and fruit yield and fostering desired traits. This is a promising strategy for indoor plant production while respecting the environment.

Soilless System with Supplementary LED Light to Obtain a High-Quality Out-of-Season Production of Green Beans

“…Instead, plant height was a morphological characteristic of the green bean plants influenced by both SL and cultivar treatments (Table 1). Similar to the results obtained by Pozzella et al [7], the green bean plants cultivated under LEDs had higher height than plants grown only with natural light (Table 1). This was due to the fact that light does not only drive photosynthesis but dictates specific signals which regulate plant development, shaping and metabolism, in the complex phenomenon of photomorphogenesis [35].…”

“…For all the treatments (light spectra and cultivar) considered during this experiment, Fv/Fm were around the optimal value of 0.8 [45] confirming that PSII efficiency was not affected by light spectra variation and genotypes (Table 5). Furthermore, the efficiency of PSII (ΦPSII) was not influenced by light treatment but was 6.5% higher in 'Saporro' than 'Maestrale' (Table 5), and a decrease in ΦPSII could indicate an inhibition of the redox reaction after the primary acceptor quinone (QA) with a slowdown in electron transfer between QA and the secondary acceptor (QB; [7]). However, the value of ΦPSII found in 'Maestrale' was not raising concerns about the photosynthetic efficiency of the PSII of this genotype [46].…”

“…In the latest years, the horticultural sector shifted its attention toward light-emitting diodes (LED) as, compared to traditional fluorescent or HPS lamps, it may reduce the energy costs due to their higher efficiency, in addition to other advantages such as longer lifetime, lower heat emission, a smaller volume/weight [7] and the possibility to be placed close to the leaves in interlighting and intracanopy irradiation [6]. Furthermore, LEDs allow to manipulate the spectral composition of light and to use the individual spectra of which the visible light is composed [8].…”

Meristematic Connectome: A Cellular Coordinator of Plant Responses to Environmental Signals?

“…Moreover, the occurrence in plants of an internal competition for resources between different root and shoot branches is another demonstration that plants are normally able A possible interpretation of this response specificity is that the plant is able to apply a "priority criterion" after a "costs-benefits" balance assessment, which resulted in costs involved in the construction of higher wood tissues area related to the benefit of a major water transport in the stem convex side and root concave side. Other examples of cost-benefit balance assessment that lead to a phenotype modification are in response to (i) quantitative and qualitative variation in the light environment [30][31][32], (ii) soil water shortage with increasing the number of very fine roots to enhance water uptake [20,33,34], and (iii) higher soil water availability which leads to an increase of fine root diameter to enhance water transportation [35].…”

Planting Density Interferes with Strawberry Production Efficiency in Southern Brazil

“…It is a cultivation technique growing strongly in Brazil and represents more than half of strawberry crops in Santa Catarina and the Rio Grande do Sul [8,23]. Biochar, an alternative for this cultivation, is natural charcoal obtained by controlled pyrolysis of organic materials (e.g., agricultural and forest residuals) [24].…”