Greenhouse Plant Production Journal

Abstract The use of medicinal plants has played an important role in maintaining health and producing herbal medicines throughout history. The increasing global demand for these plants has led to unprincipled exploitation and overharvesting of natural resources. The development of controlled cultivation methods has been proposed as an effective solution to produce high-quality products, to preserve natural ecosystems and to meet market needs. These methods not only increase the yield and quality of the product by optimizing the factors affecting growth, but are also quite effective in producing the active compounds of medicinal plants, and in this regard, they obtain more valuable plants. Along with the various advantages of these systems, the existence of several challenges has still prevented their significant expansion, which, of course, is expected to overcome recent advances. In order to achieve the full potential of these methods as a sustainable solution, more research is needed to provide useful solutions in this field.

Abstract Blueberry, scientifically known as Vaccinium L., is a small berry with high nutritional and economic value. Owing to its recognized health benefits, the demand for blueberry consumption is increasing worldwide. However, due to varying soil and climatic conditions around the world and the sensitivity of blueberries, cultivating this plant presents more limitations for growers compared to other fruit trees, creating challenges for expanding production in different regions. The goal of this research is to investigate on the challenges and solutions in the blueberry production process, including soil characteristics, climate change, the relationship between element status and plant physiological conditions and the properties of specialized cultivation substrates. We have found that the challenges within the blueberry industry can be effectively addressed by optimizing pH levels, ensuring nutrient balance and utilizing appropriate substrates. Fertilizer requirements exhibit significant fluctuations throughout the successive years of a shrub’s life cycle. Research indicates that blueberry cultivation in areas and soils exposed to heavy metals results in minimal fruit contamination, with the majority of heavy metals accumulating in the vegetative organs. Given the shallow root system of blueberries, cultivation substrate with high moisture retention capacity have proven to be well-suited. This article combines the results of a research roundtable on the challenges of blueberry production among researchers in these fields and provides insights into the importance of expanding blueberry production globally to meet the increasing demand for blueberries, while also identifying research gaps and directions for future studies.

Abstract Feijoa (Acca sellowiana) fruits have a short postharvest life of approximately 4-5 weeks under cold storage. This study, conducted in December 2023, used a completely randomized design (CRD) in a factorial arrangement to evaluate the effects of blue light exposure (6, 12, or 24 h), chemical elicitors [chitosan (CS), alginate (A), or putrescine (P) at 2 mg L⁻¹], and ethylene absorbers [none (E0), zeolite (E1), or biochar (E2)] on fruit quality during storage at 4 °C and 90-95% RH. A total of 36 treatment combinations, each with three replications (three fruits per plot), were tested on 324 fruits from uniform, commercially mature trees (~6.5 °Brix). Fruits were immersed in elicitor solutions for 30 min, dried, and exposed to blue light (λ = 470 nm) for the assigned duration before storage with or without ethylene absorber sheets characterized via BET and SEM. Quality parameters assessed included durability, respiration rate, ethylene emission, decay, firmness, weight loss, chlorophyll, ion leakage, and chilling. The combination CSE2L6 (CS + biochar + 6 h blue light) extended durability to 62/25 days compared with 31 days in the control and shelf life 216/25 hours, reduced decay by 64%, and decreased respiration rate and ethylene emission by 48% and 52%, respectively. These results demonstrate that integrating edible coatings, short-duration blue light, and ethylene absorbers can substantially extend storage life and maintain physicochemical quality in feijoa, providing an eco-friendly postharvest management strategy.

Abstract This study aimed to assess how foliar application of copper nanoparticles (Cu-NPs) influences the growth, morpho-physiological and biochemical traits of marigold plants subjected to salt stress. The study was conducted in Poldakhtar, Iran, using a greenhouse pot-based factorial experiment arranged in a completely randomized design with three replicates. Two factors were tested: foliar application of copper nanoparticles (Cu-NPs) at concentrations of 0, 100, 200, and 400 mg L⁻¹, and salinity stress induced by sodium chloride at levels of 0, 30, 60, and 90 mM. The study revealed that increasing salinity levels caused significant reductions in key growth parameters including plant height, stem diameter, leaf number, chlorophyll and carotenoid content, relative water content, root length and volume, shoot and root biomass, as well as flower size and longevity, demonstrating the pronounced negative impact of salinity stress. Concurrently, salinity stress induced physiological responses including elevated electrolyte leakage, malondialdehyde and proline levels, along with enhanced activities of antioxidant enzymes (catalase, peroxidase, ascorbate peroxidase). Foliar application of copper nanoparticles (Cu-NPs) at 100-200 mg/L effectively mitigated these stress effects by enhancing antioxidant enzyme activities, increasing proline accumulation, improving water balance, and enhancing photosynthetic pigments. The 200 mg/L Cu-NP treatment showed optimal efficacy, improving salinity tolerance through these mechanisms and demonstrating strong potential for enhancing marigold productivity in saline soils.

Abstract Sorrel (Rumex acetosa) is a nutritionally valuable leafy vegetable recognized for its high ascorbic acid, antioxidants. This study examines the effects of water sources and light treatments on sorrel growth in a vertical hydroponic system using a factorial experiment with three replications. Water treatments included distilled water (DW), quantum water (QW) and hybrid water (HW) produced through cold plasma exposure and magnetization. Light treatments involved natural greenhouse light (AL) and supplemental LED (SL). Results revealed that hybrid water combined with supplemental LED light (SL + HW) significantly enhanced vegetative parameters, including water use efficiency, chlorophyll index, and relative water content. The highest plant height (21 cm) was observed in the AL + HW treatment (27% more than control), while SL + HW has the highest root fresh weight (6.7 g). vegetative yield peaked in SL + QW and AL + QW treatments (with a 40% increase compared to the control(. Treatments SL + QW and SL + HW have the most Net photosynthesis rates (18.3 and 17.4 μmol CO₂ m⁻² s⁻¹, 47% increase compared to the control). Conversely, nitrate levels were highest in DW + AL treatments, while nitrate reductase activity was maximized in SL + HW. These findings highlight the importance of water quality and light conditions in optimizing sorrel growth in hydroponic . The SL + HW combination demonstrated the strongest effects on growth and quality, while QW paired with supplemental light also showed significant benefits. This approach supports sustainable hydroponics in water-scarce regions, ensuring reliable food production.

Abstract Four concentrations of sodium arsenate (NaH2As4O.7H2O) were investigated on lemon balm plants, including As1 = 0, As2 = 10, As3 = 20, and As4 = 30 mg As kg⁻¹ in the soil. Additionally, four concentrations of cadmium sulfate (CdSO4) were tested: Cd1 = 0, Cd2 = 10, Cd3 = 20, and Cd4 = 30 mg Cd kg⁻¹ in the soil. Cd and As exposure led to a 50.7% decrease in the dry weight of the aerial parts. Increasing the concentrations of Cd and As in the soil resulted in reductions of 18.5% and 32.01% in root dry weight, respectively. Both metals significantly lowered the concentrations of chlorophyll 'a' (72.2%) and carotenoids (71.6%), while simultaneously increasing anthocyanin levels 77.6% in the leaf tissues. The presence of Cd and As induced considerable oxidative stress, reflected by a 49.4% increase in catalase (CAT) activity and a 49.6% increase in superoxide dismutase (SOD) activity in the leaves. Furthermore, the concentrations of mineral elements such as N, P, and K were diminished in the leaves due to Cd and As. In lemon balm, a greater quantity of As compared to Cd was translocated to the aerial parts, with As exerting a more substantial effect than Cd. The concentration of Cd in the roots varied from 2.7 to 53.3 µg g⁻¹ dry weight, while in the aerial parts, it was increased by 1.5 times. For As, the concentration in the roots was elevated by 17.9 times, and in the aerial parts, it was increased 15.1 times