Greenhouse Plant Production Journal

Abstract The late-season source leaves play a decisive role in the grapevine's cold tolerance and chilling requirements. The objective was to evaluate the effect of manual late-season defoliation on the cold tolerance and chilling requirements of ‘Bidaneh-Sefid’ grapes. Treatments were applied on October 23 via manual leaf removal of the canes at four levels: 1) control (no leaf removal), 2) apical-node defoliation, 3) Basal-node defoliation, and 4) All-node defoliation of the canes. Based on the results, the lowest cold tolerance (highest electrolyte leakage, or EL) as assessed via the EL method was observed in the ‘all-node defoliation’ treatment, whereas the highest cold tolerance (lowest EL) was found in the control vines. The highest levels of glucose, fructose, sucrose, and raffinose were recorded in the control treatment, while the lowest levels of these soluble sugars were observed in the ‘all-node defoliation’ treatment. Similarly, the highest levels of putrescine, spermidine, and spermine were found in the control treatment. Abscisic acid content in the vines subjected to ‘all-node defoliation’ treatment was 28.5% lower than that of the control vines. The highest levels of gibberellin and auxin were observed in the control plants. In the defoliation treatments group, budbreak (time to 50% budburst) occurred 11 days earlier than in the control group. ‘All- node defoliation’ delayed the rate of budbreak. Overall, it was determined that late-season defoliation can reduce cold tolerance in vineyard vines, however, this horticultural practice can be employed to accelerate budbreak following a standard 400-hour chilling treatment for greenhouse grape production.

Abstract This study evaluated the effects of two biostimulant applications (soil inoculation with Trichoderma harzianum and foliar spraying of Ascophyllum nodosum seaweed extract) on the morphological characteristics of coriander (Coriandrum sativum L.) and parsley (Petroselinum crispum Mill.) grown under a soil cultivation system. The experiment was conducted as a factorial arrangement in a randomized complete block design (RCBD) with two factors: Trichoderma inoculation (control vs. 500 mg L⁻¹ applied twice) and seaweed extract foliar application (control vs. 1 g L⁻¹ applied four times). Growth parameters measured included plant length (PL), plant volume (PV), leaf number (LN), plant fresh mass (PFM), plant dry mass (PDM), and dry matter percentage (DM). For coriander, Trichoderma application significantly increased PL, PV, LN, PFM, and PDM, while seaweed foliar application significantly improved PV, LN, PFM, and PDM. The interaction between Trichoderma and seaweed was significant for LN, PFM, and PDM, with the combined application producing the highest values for these parameters. For parsley, Trichoderma application significantly enhanced PL, PV, PFM, and PDM, and also significantly reduced DM. Seaweed foliar application alone significantly increased only PL. The interaction effect was significant only for DM. Principal component analysis (PCA) confirmed that Trichoderma and seaweed biostimulants, particularly when applied together, can effectively improve the morphological characteristics and productivity of coriander, while Trichoderma alone provides notable benefits for parsley under soil cultivation conditions.

Abstract Efficient vegetative propagation of grapevine depends on successful adventitious root formation, which is influenced by genotype, auxin supply, rooting environment, and biological interactions. The present study evaluated the individual and interactive effects of rooting medium, indole-3-butyric acid (IBA), and arbuscular mycorrhizal fungi (AMF) on the rooting performance of Vitis vinifera L. cv. Sistan Yaghooti cuttings. A three-factor factorial experiment was conducted under a completely randomized design using three rooting media (sand, soil, and cocopeat + perlite), three IBA concentrations (0, 2000, and 4000 mg L⁻¹), and four fungal treatments (non-inoculated control, Glomus intraradices, G. mossaea, and SuperMychoPlus). Rooting success and root-system traits were evaluated after approximately two months. Analysis of variance revealed significant effects and interactions among rooting medium, IBA concentration, and fungal treatment for several rooting traits, including significant three-way interactions. These results indicate that rooting responses strongly depended on the specific combination of IBA concentration, fungal treatment, and rooting medium. For example, the sand + 2000 mg L⁻¹ IBA combination averaged 2.42 rooted cuttings per experimental unit, corresponding to 40.3% rooting, whereas the soil + untreated control averaged 0.58 rooted cuttings (9.7%). Several cocopeat + perlite combinations supported greater development of root-system traits, including root number and total root length. Thus, rooting success and root-system development did not necessarily follow the same response pattern. Overall, the findings indicate that propagation of Sistan Yaghooti grapevine should be evaluated using integrated treatment combinations rather than considering IBA concentration, fungal treatment, or rooting medium independently.

Abstract Basil (Ocimum basilicum L.), a member of the Lamiaceae family, is among the most commercially significant medicinal and aromatic plants worldwide. The increasing demand for standardized, high-quality raw material has driven a shift from open-field cultivation to greenhouse production. However, the literature on basil phytochemistry and pharmacology has rarely been connected to greenhouse cultivation and stress physiology, and no unified framework links these topics. This review therefore synthesizes current knowledge on basil's bioactive constituents, their pharmacological activities, and the responses of basil to water deficit stress in greenhouse and other controlled-environment systems, with emphasis on recent advances and Iranian landraces. Basil produces a large number of metabolites (830 volatile compounds were detected in a recent leaf study), including rosmarinic acid, flavonoids, and volatile terpenoids, many of which exhibit antioxidant, antimicrobial, anti-inflammatory, hypoglycemic, neuroprotective, and anticancer activities. In greenhouse systems, water deficit is not an unavoidable stress but a manageable tool: mild to moderate, controlled deficit increases secondary metabolite production through upregulation of phenylpropanoid pathway genes, raising total phenolics by up to 40% and rosmarinic acid by up to 30%, whereas severe stress reduces biomass by more than 45%. Soilless systems offer the precise water and nutrient control needed to apply such strategies, so that yield and phytochemical quality can be balanced. Iranian native landraces are promising genetic resources for stress tolerance and phytochemical quality in greenhouse breeding programs. We conclude that controlled, mild to moderate deficit irrigation combined with precise greenhouse management can raise the concentration of bioactive compounds in basil, provided that biomass losses are kept low; future research should prioritize multi-omics approaches, CRISPR-based breeding, and sustainable greenhouse cultivation strategies.

Abstract The selection of an appropriate explant type is a critical factor influencing the efficiency of grapevine micropropagation. Nevertheless, comparative information on explant-dependent responses remains limited for several commercially valuable grape cultivars. This study evaluated three explant types of Vitis vinifera L. cv. Mondrop, focusing on growth, biomass accumulation, and culture-related abnormalities. Shoot tips, nodal segments, and buds developing near callus tissue were cultured on Murashige and Skoog (MS) medium. Following establishment, developing shoots were transferred to MS medium supplemented with 0.5 mg L⁻¹ benzyladenine (BA) for multiplication. The experiment was conducted using a completely randomized design with three replicates. Shoot length, leaf and node number, fresh and dry weight, hyperhydricity, and shoot-tip necrosis were evaluated. Explant type markedly affected in vitro performance. Nodal explants produced the longest shoots (3.75 cm), highest leaf (4.03) and node (3.48) numbers, and greatest fresh (320 mg) and dry (102 mg) biomass. In contrast, buds developing near callus tissue showed the lowest values for these traits, with shoot length, leaf number, node number, fresh weight, and dry weight of 2.74 cm, 2.38, 2.32, 190 mg, and 55 mg, respectively. Nodal explants also exhibited the lowest hyperhydricity (1.01%) and shoot-tip necrosis (0.90%), whereas buds near callus tissue showed the highest incidences (5.11% and 3.12%, respectively). Overall, nodal explants provided the most favorable combination of growth, biomass accumulation, and culture quality under the tested conditions. These findings highlight the importance of explant selection for efficient grapevine micropropagation and provide a practical basis for developing a propagation system for cv. Mondrop.

Abstract Nanoparticles of silicon dioxide (SiO2-NPs) have been demonstrated as possible modifiers of plant responses to abiotic stress. This study investigated the effects of SiO2-NPs at 0, 50 and 100 mM under normal and water-stress circumstances on the various traits of tomato (Solanum lycopersicum L.) seedlings cultivated in an aeroponic system. The trial was done in a factorial layout according to completely randomized design. The measured traits were plant height, root length, root characteristics, proline, chlorophyll pigments, relative water content, anthocyanins, phenolic compounds, activities of antioxidant enzymes, protein, sodium and potassium. The results indicated that the impacts of SiO2-NPs were variable among traits and water regimes. The 50 mM treatment increased root volume from 13.8 to 15.8 cm3 under water stress. The 100 mM treatment had higher chlorophylls a and b as well as catalase activity and phenolics. The proline content decreased with increasing nanoparticle concentration; however, ascorbate peroxidase activity did not increase under water stress. Relative water content showed numerical increase at 50 mM but decrease at 100 mM as compared to stressed control. The highest shoot dry weight was recorded in the water-stressed untreated control, followed by the 50 and 100 mM SiO₂-NP treatments, while under non-stress conditions, it decreased at both nano-particle treatments compared with the untreated control. The findings indicated that the reaction of tomato seedlings to SiO2-NPs application was concentration-dependent and trait-specific, and not a general improvement of tomato seedling performance.