In modern agriculture, Controlled environment agriculture (CEA) stands out as a contemporary production mode that leverages precise control over environmental conditions such as nutrient, temperature, light, and other factors to achieve efficient and high-quality agricultural production. Numerous studies have demonstrated the efficacy of manipulating these environmental factors in the short period before harvest to enhance crop yield and quality in CEA. This comprehensive review aims to provide insight into various pre-harvest practices employed in CEA, including nutrient deprivation, nutrient supply, manipulation of the light environment, and the application of exogenous hormones, with the objective of improving yield and quality in horticultural crops. Additionally, we propose an intelligent pre-harvest management system to cultivate high-quality horticultural crops. This system integrates sensor technology, data analysis, and intelligent control, enabling the customization of specific pre-harvest strategies based on producers’ requirements. The envisioned pre-harvest intelligent system holds the potential to enhance crop quality, increase yield, reduce resource wastage, and offer innovative ideas and technical support for the sustainable development of CEA.

The effects of silicon (Si) on temperature stresses were investigated in poinsettia. Well-rooted cuttings supplemented with and without Si were exposed to 40 °C, and plants treated with or without Si during cutting propagation and cultivation were subjected to 4 °C. The results showed that almost all the stomata of cuttings without Si supplementation were closed, while some of them were still open in cuttings supplemented with Si under a high temperature stress. However, Si was not able to alleviate stomatal closure of poinsettia under low temperature stress. The increased epicuticular wax might contribute to enhanced resistance of poinsettia to low temperature stresses. In addition, poinsettia maintained a higher photosynthetic rate and lower malonaldehyde and hydrogen sulfide concentrations when supplemented with Si under high and low temperature stresses, which might contribute to lower APX activities. Overall, temperature stresses had negative impacts on the physiological characteristics of poinsettia, while Si could alleviate some effects of temperature stresses.

Peony is an important ornamental plant and has become increasingly popular for cut flower cultivation. However, a short vase life and frequent poor vase quality severely restrict its market value. The study described herein was conducted to investigate the effects of silicon application on the vase life and quality of two cut peony (Paeonia lactiflora Pall.) cultivars, ‘Taebaek’ and ‘Euiseong’. For pre- and/or postharvest silicon application, four experimental groups based on treatments were designed. With silicon treatment, the relevant growth attributes, including the shoot and leaf lengths, stem and bud diameters as well as the leaf width were all remarkably increased. In the postharvest storage, the addition of silicon to the holding solution in the vase was able to significantly extend vase life, delay fresh weight decrease, and improve vase quality, as characterized by the antioxidant enzyme activities and mechanical stem strength. Taken together, silicon application, regardless of the approach, was able to effectively prolong the vase life and enhance the quality of cut peony flowers.

Lower quality and longer production periods of grafted seedlings, especially grafted plug seedlings of fruit vegetables, may result from insufficient amounts of light, particularly in rainy seasons and winter. Supplemental artificial lighting may be a feasible solution to such problems. This study was conducted to evaluate light intensity’s influence on the quality of grafted tomato seedlings, ‘Super Sunload’ and ‘Super Dotaerang’ were grafted onto the ‘B-Blocking’ rootstock. To improve their quality, grafted seedlings were moved to a glasshouse and grown for 10 days. The glasshouse had a combination of natural lighting from the sun and supplemental lighting from LEDs (W₁R₂B₂) for 16 h/day. Light intensity of natural lighting was 490 μmol·m⁻²·s⁻¹ photosynthetic photon flux density (PPFD) and that of supplemental lighting was 50, 100, or 150 μmol·m⁻²·s⁻¹ PPFD. The culture environment had 30/25 °C day/night temperatures, 70% ± 5% relative humidity (RH), and a natural photoperiod of 14 h as well. Compared with quality of seedlings in supplemental lighting of 50 μmol·m⁻²·s⁻¹ PPFD, that of seedlings in supplement lighting of 100 or 150 μmol·m⁻²·s⁻¹ PPFD improved significantly. With increasing light intensity, diameter, fresh weight, and dry weight, which were used to measure shoot growth, greatly improved. Leaf area, leaf thickness, and root biomass were also greater. However, for quality of seedlings, no significant differences were discovered between supplement lighting of 100 μmol·m⁻²·s⁻¹ PPFD and supplement lighting of 150 μmol·m⁻²·s⁻¹ PPFD. Expressions of PsaA and PsbA (two photosynthetic genes) as well as the corresponding proteins increased significantly in supplement lightning of 100 and 150 μmol·m⁻²·s⁻¹ PPFD, especially in 100 μmol·m⁻²·s⁻¹ PPFD. Overall, considering quality and expressions of two photosynthetic genes and proteins, supplemental light of 100 μmol·m⁻²·s⁻¹ PPFD (W₁R₂B₁) would be the best choice to cultivate grafted tomato seedlings.

Commercial strawberries are mainly propagated using daughter plants produced on aerial runners because asexual propagation is faster than seed propagation, and daughter plants retain the characteristics of the mother plant. This study was conducted to investigate the effective factors for runner induction, as well as the molecular mechanisms behind the runner induction. An orthogonal test with 4 factors (photoperiod, temperature, gibberellin, and 6-benzyladenine), each with 3 levels was performed. Proteins were also extracted from the crowns with or without runners and separated by two-dimensional electrophoresis. The results of the orthogonal test showed that a long-day (LD) environment was the most influential factor for the runner formation, and 50 mg·L⁻¹ of 6-BA significantly increased the number of runners. A proteomic analysis revealed that 32 proteins were differentially expressed (2-fold, p < 0.05) in the strawberry crowns with and without runners. A total of 16 spots were up-regulated in the crowns with runners induced by LD treatment. Identified proteins were classified into seven groups according to their biological roles. The most prominent groups were carbohydrate metabolism and photosynthesis, which indicated that the carbohydrate content may increase during runner formation. A further analysis demonstrated that the soluble sugar content was positively correlated with the number of runners. Thus, it is suggested that the photoperiod and 6-BA break the dormancy of the axillary buds and produce runners by increasing the soluble sugar content in strawberry.

Seleno-amino acids are safe, health-promoting compounds for humans. Numerous studies have focused on the forms and metabolism of seleno-amino acids in vegetables. Based on research progress on seleno-amino acids, we provide insights into the production of selenium-enriched vegetables with high seleno-amino acids contents. To ensure safe and effective intake of selenium, several issues need to be addressed, including (1) how to improve the accumulation of seleno-amino acids and (2) how to control the total selenium and seleno-amino acids contents in vegetables. The combined use of plant factories with artificial lighting and multiple analytical technologies may help to resolve these issues. Moreover, we propose a Precise Control of Selenium Content production system, which has the potential to produce vegetables with specified amounts of selenium and high proportions of seleno-amino acids.