Optimizing Plants and Cultivation System for Controlled Environment Agriculture (CEA)

A three-year study was conducted to investigate the effects of two timings—at berry set and at veraison—of post-bloom leaf removal (LR) applications from the basal sections of the shoot on the growth, yield, and berry composition of Vitis vinifera L. cv. Xinomavro, the major red winegrape of North Greece. LR at berry set drastically reduced yield by affecting all its components while increasing the ratio of secondary foliage per total leaf area. LR at veraison had a milder effect on growth and yield. Both treatments increased sugar and phenolic compound levels in berries, while early LR increased the contribution of more stable forms of anthocyanins. Additionally, early LR increased the skin-to-pulp ratio, suggesting that it could be an effective viticultural technique for more concentrated red wines. Overall, both LR timings improved most of the berry attributes compared to the non-treated vines; however, the earlier application can be recommended when aiming at the production of deep-colored and richly flavored wines. Full article

The total land used for land-based food farms is less than 1% in Singapore. As a result, more than 90% of Singapore’s food needs are imported. To strengthen food security, Singapore has set a target to develop the capability and capacity of the agri-food industry to locally produce 30% of its nutritional needs by 2030. To achieve this goal, technology is the key to helping farms to “grow more with less”. This review first discusses how aeroponic systems have been adapted for growing all kinds of leafy vegetables in the tropics through the manipulation of root-zone temperature and heat priming to save power energy. Growing vegetable crops indoors and in greenhouses not only allows the growers to achieve high productivity but also enables them to enhance nutritional values. The second part of this paper emphasizes how to achieve substantial yield through deficit irrigation with higher nutritional quality in a cost-effective manner. Growing crops vertically has become increasingly popular, as it increases land use. We establish a commercially viable LED-integrated aeroponic system to grow vegetables vertically. The last part of the paper discusses the impacts of LED spectral quality, quantity, and duration on vegetable production. Full article

The sunlight greenhouse crops receive varies and is often insufficient for consistent year-round growth in greenhouses. Supplemental lighting is commonly applied in winter, but this practice has a significant energy cost, accounting for 10–30% of operating expenses and impacting greenhouse profitability. Greenhouse lights are traditionally adjusted based on sunlight intensity to meet crops’ daily light requirements. However, if plants can withstand lower daily light integrals (DLI) after a sunny day without reducing the growth, there is potential to reduce the energy required for supplemental lighting and increase the profit. To determine whether excess light received one day can be ‘carried over’ to the next, we grew oakleaf lettuce (Lactuca sativa ‘Green Salad Bowl’ and ‘Red Salad Bowl’) under six lighting regimes inside a vertical farm. Plants in all treatments received an average DLI of 15 mol·m⁻²·d⁻¹, but DLIs alternated from day-to-day (15/15, 17.5/12.5, 20/10, 22.5/7.5, 25/5, and 27.5/2.5 mol·m⁻²·d⁻¹), resulting in DLI fluctuations from 0 to 25 mol·m⁻²·d⁻¹. Plants had similar leaf area (~800 cm²/plant) and dry weight (~1.8 g/plant) when grown with DLI fluctuations from 0 to 15 mol·m⁻²·d⁻¹, while higher DLI fluctuation reduced growth. To confirm this DLI “carrying-over” effect on plants grown under sunlight with supplemental light, we conducted a second study in a greenhouse with ‘Green Salad Bowl’ lettuce. In this study, plants were grown with five different DLI fluctuations (15/15, 16.75/13.25, 18.5/11.5, 20.25/9.75, and 22/8 mol·m⁻²·d⁻¹), ranging from 0 to 14 mol·m⁻²·d⁻¹, while maintaining an average DLI of 15 mol·m⁻²·d⁻¹ in all the treatments. We observed similar leaf area (~750 cm²/plant) and dry weight (~1.8 g/plant) in lettuce plants grown with DLI fluctuations from 0 to 10.5 mol·m⁻²·d⁻¹. Higher DLI fluctuations reduced growth. Hence, carrying excess light from a sunny to an overcast day is possible within limits. Our study concluded that the DLI requirement can be reduced by approximately 5.25 mol·m⁻²·d⁻¹ on the day following a sunny day. By analyzing historical weather data from five US locations, we quantified the potential annual energy savings from incorporating this ‘carrying-over DLI’ concept. This approach resulted in annual energy savings of approximately 75–190 MWh/ha in greenhouse lettuce production. Such reductions in supplemental lighting energy will enhance the profitability and sustainability of the greenhouse industry. Full article

Experimental studies were conducted on the cultivation of tomatoes (Solanum lycopersicum L.) at Shandong Agricultural University, China, from 2022 to 2023. Three cultivation patterns were designed as follows: a north–south orientation with a row spacing of 1.40 m (NS-1.4m), a north–south orientation with a row spacing of 1.80 m (NS-1.8m) and an east–west orientation with a row spacing of 1.80 m (EW-1.8m). A functional–structural plant model using the open source interactive modeling platform of GroIMP was constructed for the cultivation of tomatoes. The growth of plants as well as the light distribution and light interception capacity of the crop canopy were simulated and analyzed. The impacts of these cultivation patterns on the growth, photosynthetic characteristics, fruit ripening time, quality and yield of tomato plants were analyzed. The studies revealed that compared with the NS-1.4m treatment, the canopy light interception of tomato plants under the NS-1.8m and EW-1.8m treatments increased by 6.08% and 9.80% in a winter–spring crop and 6.80% and 19.76% in an autumn–winter crop, respectively. Their plant height, leaf area, aboveground dry matter accumulation, leaf net photosynthesis rate as well as the lycopene, vitamin C and sugar–acid ratio of the fruit all exhibited increasing trends, while fruit ripening was accelerated. The yield of the NS-1.8m and EW-1.8m treatments increased by 3.92% and 6.18% in a winter–spring crop and 4.17% and 9.78% in an autumn–winter crop, respectively. Structural equation modeling was used to further analyze the data, confirming that the cultivation of an east–west orientation with wide row spacing is beneficial for tomato cultivation in Chinese solar greenhouses. This cultivation pattern maximizes the canopy’s light interception, thus leading to improved fruit quality and yield. Overall, this study provides valuable insights for optimizing the cultivation pattern of solar greenhouse crops. Full article

Ensuring the technical and technological possibility of regularly obtaining fresh, high-quality plant production in Antarctic stations is an urgent task of our time. This work is devoted to studying the growth and development of leaf vegetable crops and the main quality indicators of their edible parts when grown in the phytotechnical complex greenhouses at the “Vostok” Antarctic station and at the agrobiopolygon of the Agrophysical Research Institute (AFI). The plants, belonging to 13 varieties of 9 types of leaf vegetable crops (arugula, garden cress, cabbage, mustard, leaf radish, leaf lettuce, amaranth, dill, parsley leaf), were studied during five growing seasons at the “Vostok” station and at the AFI agrobiopolygon under controlled conditions (control). The experimental data obtained demonstrate the high productivity of the phytotechnical complex for most of the investigated crops per unit of useful area, with lower costs of electricity and water consumption per unit of production compared with a number of greenhouses at foreign Antarctic stations and greenhouse complexes with controlled conditions located on other continents. Lettuce crops were the most adapted to the growing conditions at the Antarctic station “Vostok”. They did not differ in their evaluated characteristics from the control. All other investigated crops, while not differing in their development rate and quality, had statistically significant (16–61%) decreases in their yield per 1 m² per year. This may demonstrate the difference in the “genotype–environment” interaction in plants grown at the Antarctic station and AFI agrobiopolygon, probably due to the different barometric pressure and partial pressure of oxygen at the two locations. The positive psychological effects of the greenhouses were identified along with nutritional and other qualities of the plants. Full article

Lilies are important crops that are commonly used as cut flowers (Lilium spp.) and edible bulb crops (Lilium davidii var. unicolor). However, virus infections can significantly impact the quantity and quality of lily production. Various methods have been developed to eliminate viruses in lilies, including in vitro culture and virus detection techniques. Meristem culture is the most effective method, which can be combined with other techniques such as thermotherapy and chemotherapy. Nonetheless, virus elimination is affected by several factors, including cultivar, explants used, virus type, and duration of treatments. Efficient diagnostic methods, such as serological and molecular techniques, have been developed to detect viral infections in lilies, including enzyme-linked immunosorbent assay (ELISA) and real-time reverse transcriptase polymerase chain reaction (real-time RT-PCR). However, cross-contamination and multiple-virus contamination can lead to unreliable results, and more sophisticated protocols and systems have been developed to address these issues. The objective of this review is to provide a comprehensive overview of the development of lily virus eradication, detection strategies, challenges, and solutions associated with these procedures, and how more sophisticated approaches such as multiplex RT-PCR, indirect ELISA (ID-ELISA), immunocapture RT-PCR (IC-RT-PCR), and immunochromatographic test strips (ICSs) can alleviate some of these setbacks. Full article

Soilless cultivation represents a promising method for the future of the horticulture industry as it offers advantages such as improved quality control over the growth environment and mitigation of uncertainties related to soil, water, and nutrient availability. In this study, we aimed to investigate the effects of different environments, specifically greenhouse (GH) and open-field (OF), on the growth, phenotypic characteristics, physio-biochemical properties, qualitative parameters, and antioxidant capacity of strawberries cultivated using a soilless system. The aforementioned parameters were measured in both the GH and OF settings. Our findings revealed that the growth, yield, and morphological parameters were significantly higher in the GH environment compared to the OF. However, when considering fruit quality indices such as fruit texture firmness, fruit dry matter percentage, taste index (TSS/TA ratio), and post-harvest shelf-life, the OF cultivation method exhibited significantly superior results. Moreover, various aspects, related to plant physiology and biochemistry, antioxidant enzyme activity, total antioxidant capacity (DPPH), vitamin C content, and secondary metabolites, were found to be significantly higher in the OF environment compared to the GH. Overall, the results of our study suggest that OF soilless cultivation outperforms GH cultivation in terms of fruit quality, antioxidant capacity, and post-harvest shelf-life. Despite the observed decrease in fruit growth and yield, soilless strawberries grown in OF are likely to yield a final product of higher quality and nutritional value compared to those cultivated in a GH environment. These findings highlight the potential of OF soilless cultivation as a viable approach for strawberry production, emphasizing the importance of considering not only yield but also qualitative aspects and the nutritional value. Further exploration and optimization of soilless cultivation techniques in OF settings could contribute to the advancement of sustainable horticultural practices. Full article

Efficient water management is crucial for sustainable agriculture and water resource conservation, particularly in water-scarce regions. This study investigated the effect of different irrigation depths on onion (Allium cepa L.) yield and water use patterns in a semi-arid tropical region of Colombia, using a completely randomized design with five treatments. The treatments ranged from 0–100% of total available water (TAW), T1 (100% of TAW), T2 (80% of TAW), T3 (60% of TAW), T4 (40% of TAW), and T5 (20% of TAW). The experiment was conducted in a greenhouse during one growing season (2022–2023). The normalized water productivity (WP *), irrigation water productivity (IWP), consumptive water productivity, blue water footprint (WF_blue), marginal water use efficiency (MWUE), and elasticity of water productivity (EWP), as well as some parameters of quality onion, were determined. The soil in the experimental field was classified as sandy loam; the results show that the WP * of onion is 17.42 g m⁻², the water production function shows the maximum production will be achieved at a water application depth of approximately 943 mm, and beyond that, the biomass yield will decrease with additional water application, IWP values for onion ranged from 2.18 to 3.42 kg m⁻³, the highest Wf_blue was in T5 (34.10 m³ t⁻¹), and low Wf_blue was T1 (20.95 m³ t⁻¹). In terms of quality, treatment T1 had the most favorable effects on bulb weight, polar diameter, and equatorial diameter, while treatment T5 had the least favorable effects. The study highlights the importance of efficient irrigation on sandy loam soils to maximize yield and water use efficiency. It provides valuable data for evaluating the potential yield benefits of precision irrigation in the study area. Optimizing irrigation depth can significantly improve onion yield and water use efficiency in semi-arid regions. Full article