Supplementary Light on the Development of Lettuce and Cauliflower Seedlings

Abstract

The production of seedlings is one of the main activities for implementing agricultural crops. Many factors are involved in producing quality seedlings, including nutrition, health, genetics, and climatic factors such as temperature, humidity, and light. To evaluate the effect of light supplementation, a study was conducted using supplementary artificial light to produce lettuce and cauliflower seedlings. Sowing was carried out in styrofoam trays under a floating irrigation system. Part of the experiment containing the two species, received treatment with LED light for an additional 4 h per day, in addition to solar radiation (10 h∙day−1). The remaining seedlings received only solar radiation (without supplementation). After 37 days, the seedlings’ biometric (leaf area, root length, aerial dry mass, and root dry mass) and biochemical parameters (phenolic compounds, flavonoids, chlorophyll a/b, and total chlorophyll) were analyzed. The data showed that the complementary light enhanced the performance in all the biometric parameters evaluated in the experiment for lettuce and cauliflower. The biochemical parameters in lettuce were also higher in seedlings with light supplementation. For cauliflower, supplementary light did not differ from the natural photoperiod for biochemical parameters except for a reduction in the levels of total phenolic compounds. Considering the enhanced biometric and biochemical parameters and greater dry weight and leaf area of the seedlings grown with supplemental light, using such a tool can optimize seedling development, possibly reducing production time in the nursery and providing greater productivity.

Preliminary Study on the Effect of Artificial Lighting on the Production of Basil, Mustard, and Red Cabbage Seedlings

“…Figure 4 shows the root and aerial parts of red cabbage and mustard seedlings grown under natural light (T1) and with purple LED light supplementation (T2). Red cabbage Rizzon et al [46], working with purple LED light supplementation (87.5 % red-670 nm + 12.5 % blue-430 nm) on curly lettuce and cauliflower seedlings in a greenhouse, observed that the biometric parameters of ADM, DRM, root length, and LA evaluated were positively influenced by light supplementation in both species. The same author commented that the use of lighting promoted the faster development of seedlings, indicating a shorter nursery time and, consequently, increased productivity compared to systems without supplementary lighting.…”