Effect of shading on Dimorphandra gardneriana Tul. seedling production

Abstract

The study of plant behavior in environments with different luminous intensities offers information about their ability to modify their growth and performance in response to light. The objective of this study was to evaluate the influence of shading on the development of Dimorphandra gardneriana Tul. Different levels of shading were used, with 0% shading (full sun)-(T 1), 30%-(T 2), 50%-(T 3) and 70% shading-(T 4). The different levels of shading were obtained by means of black polyolefin screens, sombre type, each treatment consisting of four replicates of 15 plants. The evaluated characteristics were: number of leaves, plant height, neck diameter, survival percentage, shoot length and primary root, green and dry mass of shoots and roots, total dry mass, Dickson quality index and (AP/MSPA), shoot height and diameter (A/DC), aerial part and root dry mass (MSPA/MSR), shoot height and dry mass (CPA/CR), as well as the percentage of roots (%R). The shading influenced negatively the quality of D. gardneriana seedlings, being those grown in full sun the ones that presented the best quality. Based on the morphological parameters studied, it can be affirmed that the D. gardneriana Tul., seedlings, produced in an open environment with high luminosity showed superior qualities in relation to the shaded seedlings.

Manipulating the Difference between the Day and Night Temperatures Can Enhance the Quality of Astragalus membranaceus and Codonopsis lanceolata Plug Seedlings

“…Importantly, the DQI was greater in seedlings grown with the +10 • C DIF than those in the other two treatments, implying the ability of the +10 • C DIF to yield high-quality plug seedlings. The biomass, stem diameter, and DQI are important parameters used to evaluate the quality of seedlings [34][35][36]. These results were in accordance with previous studies in tomato [19,37] and sweet pepper [38].…”

Carbon Dioxide Enrichment Combined with Supplemental Light Improve Growth and Quality of Plug Seedlings of Astragalus membranaceus Bunge and Codonopsis lanceolata Benth. et Hook. f.

“…Plants grown with supplemental lighting had significantly higher shoot and root dry weights, stem diameter, leaf area, and Dickson's quality index (DQI), in comparison with plants grown without supplemental lighting (Figure 1, Tables 1 and 2). As an important parameter, DQI is a good indicator of seedling quality since changes in the strength and balance of the distribution of biomass are assessed, and several other important parameters are used to assess the quality [48]. Therefore, a significantly lower value of DQI under no supplemental lighting (Con) suggested any supplemental lighting greatly upgraded the quality of plus seedlings of A. membranaceus and C. lanceolata.…”