Growth Of Tomato Plants Research Articles

Effects of neodymium magneto-priming on seed germination and salinity tolerance in tomato.

Earth's biosphere is surrounded by magnetic fields that affect all living organisms. A plant's response to magnetic fields is displayed in terms of its seed's vigor, growth, and yield. Examining seed germination in such magnetic fields is the first step in the investigation of how magnetic fields might be used to enhance plant growth and maximize crop performance. In this study, salinity-sensitive Super Strain-B tomato seeds were primed with the northern and southern poles of neodymium magnets of 150, 200, and 250 mT. The magneto-primed seeds showed a significant increase in germination rate and speed, where the orientation of the magnet was identified as being crucial for germination rate and the orientation of seeds towards the magnet was shown to affect the germination speed. The primed plants exhibited enhanced growth characteristics, including longer shoots and roots, larger leaf area, more root hairs, higher water content, and more tolerance to salinity levels, up to 200 mM NaCl. All magneto-primed plants showed a significant decrease in chlorophyll content, continuous chlorophyll fluorescence yield (Ft), and quantum yield (QY). The salinity treatments decreased all chlorophyll parameters in control plants, significantly, but did not lower such parameters in magneto-primed tomatoes. The results of this study illustrate the positive effects of neodymium magnet on the growth and development of tomato plants in terms of their germination, growth, and salinity tolerance, and negatively affected the chlorophyll content in tomato leaves. © 2023 Bioelectromagnetics Society.

Effects of water and salt stresses on plant growth and xylem hydraulic properties of tomato.

Xylem is the main tissue for water transport in plants, and the changes of hydraulic properties in which would affect plant water relations and fruit water accumulation. It remains unclear regarding the responses of xylem anatomy and hydraulic properties to water and salt stresses in tomato plants and their relationships with plant growth and fruit water content. We conducted a pot experiment in a greenhouse to investigate the responses of plant growth, fruit water content, and xylem hydraulic properties of a cherry tomato (Hong Baoshi) and a medium-fruited tomato (Beifan 501). There were three treatments, control with a soil water content (θ) of 75%-95% of field capacity (FC) and an initial electrical conductivity (EC) of 0.398 dS·m-1; water stress with θ of 75%-95% of FC (before flowering) and 45%-65% of FC (from flowering until maturity) and an EC of 0.398 dS·m-1; and salt stress with θ of 75%-95% of FC and an EC of 1.680 dS·m-1. Results showed that water and salt stresses decreased the cross-sectional stem area and xylem vessel diameter by 22.0%-40.7% and 10.0%-18.3%, respectively, and reduced the specific hydraulic conductivity of stem and the hydraulic conductivity of peduncle by 8.8%-41.1% and 12.9%-28.4%, respectively. Those changes inhibited plant growth and reduced aboveground fresh weight, fruit size, fresh weight and water content, with a more pronounced negative effect in the medium-fruited tomato. More-over, fruit water content was positively correlated with the specific hydraulic conductivity of stem and peduncle. In conclusion, water and salt stresses would inhibit plant growht, fruit fresh weight, and consequently tomato yield, due to their negative effects on xylem hydraulic properties of the tomato plant. Medium-fruited tomatoes are more susceptible to water and salt stresses than cherry tomatoes.

番茄生长过程储存模态信息的植株生物电路模型构建

During the growth and development of tomato plants, its different cells or tissues would store external environmental information and express it in the form of ion transportation. In order to better examine the storage model of tomato plants, the tomato individual tissue and whole plant biological circuit models were closely examined based on the idea of modal theory. According to the parameter inversion theory, in the frequency range of 0.1Hz - 1MHz, the impedance spectrum measurement and dielectric properties of tomato plants in four modal periods of germination stage were carried out. The stages were namely the seedling stage, flowering and fruit setting stage, and fruiting stage respectively. Impedance spectrum fitting was performed with the ZSimpWin software. Then, the biological circuit model of each tissue of tomato plant was obtained. Next, the parameter inversion was used to calculate the value of each element of the biological circuit model. Lastly, the biological circuit model of the tomato plant body in each period was obtained. Through the charging and discharging test of the model of the tomato plant body at each stage, the corresponding parameter value relationship was obtained according to the capacitance characteristics. This would be compared with the component values obtained from the parameter inversion in the model. Results showed that the errors were all less than 4.8%, which verified the rationality of the model. This system acted as a theoretical guidance for the research on the growth and development of tomato and other plants.

EFEKTIVITAS BERBAGAI AGENS HAYATI DALAM MENINGKATKAN PERTUMBUHAN TANAMAN TOMAT (Lycopersicum esculentum Mill.)

The research aims to determine the effectiveness of various biological agents in increasing the growth of tomato plants. The study used a randomized block design, consisting of 10 treatments, namely without the use of biological agents, Pseudomonas sp. SWRIIA02, Bacillus sp. CKD061, Pseudomonas sp. Ab06, Pseudomonas sp. Bb05, SWRIIA02 + CKD061, Ab06 + CKD061, Bb05 + CKD061, SWRIIA02 + CKD061 and SWRII02 + CKD061 + Bb05 and each treatment was repeated 3 times. The results showed that the treatment of biological agents had a very significant effect on plant height 14 DAP, number of leaves 12 DAP, plant dry weight and significantly affected plant height 28 DAP, 42 DAP, stem diameter 42 DAP, root fresh weight, root dry weight and length root. The biological agent Pseudomonas sp. SWRIIA02, Bb05+CKD061, Bacillus sp. CKD061, SWRIIA02+CKD061+Bb05 were better at increasing the growth of local tomato plants compared to those without biological agents, with the percentage increase in plant dry weight in each of these treatments reaching 62.30%, 58.78%, 55.91% and 51.76% which was not significantly different from other treatments but significantly different from the treatment without biological agents.

Effects of different liquid fertilizers developed from livestock manure on plant growth and antioxidant activity of tomato (Solanum lycopersicum L.)

Effects of different liquid fertilizers developed from livestock manure on plant growth and antioxidant activity of tomato (Solanum lycopersicum L.)

Fertilisation with compost mitigates salt stress in tomato by affecting plant metabolomics and nutritional profiles

BackgroundSalinity is one of the major threats for crop growth and yield and its rate of expansion is expected to increase. We conducted a pot experiment to evaluate and compare the effect of a green compost addition and mineral fertilisation, on growth, nutrition and metabolites of tomato plants, exposed to increasing doses of NaCl.ResultsAlthough the development of stressed plants was lower than the corresponding controls, compost-treated plants performed better than mineral-amended plants watered with the same amount of salt. The different plant growth was related to an increased nutritional status. Namely, compost-treated plants showed a larger content of macro- and micronutrients, and a greater accumulation of osmoprotectants, such as soluble sugars and amino acids. Moreover, compost-treated plants showed a larger content of metabolites involved in modulating the response to salt stress, such as molecules related to energy transfer in plants and precursors of Reactive Oxygen Species scavenging compounds. Overall, the better performance of compost-added plants may be attributed to a greater availability of the organic forms of nutrients and to the positive bioactivity of compost-derived humic substances.ConclusionsCompost application efficiently mitigated salt stress in tomato plants in respect to mineral fertilisation. This alleviating role was associated to the induction of a more efficient metabolic response that increased accumulation of metabolites involved in modulating the salinity stress. Therefore, fertilising with composted agricultural residue may represent a convenient alternative to mineral fertilisers to grow tomato plants in the presence of salt stress.Graphical

Impact of the application of some Friendly Environment Materials on Tomato Plants Grown under High Temperature Conditions

Impact of the application of some Friendly Environment Materials on Tomato Plants Grown under High Temperature Conditions

Cardiolipin synthesis in Pseudomonas fluorescens UM270 plays a relevant role in stimulating plant growth under salt stress

Membrane cardiolipin (CL) phospholipids play a fundamental role in the adaptation of bacteria to various environmental conditions, including saline stress. Here, we constructed deletion mutants of two CL synthetase genes, clsA (UM270 ∆clsA) and clsB (UM270 ∆clsB), in the rhizobacterium Pseudomonas fluorescens UM270, and evaluated their role in plant growth promotion under salt stress. UM270 ∆clsA and UM270 ∆clsB mutants showed a significant reduction in CL synthesis compared to the P. fluorescens UM270 wild-type (UM270 wt) strain (58% ∆clsA and 53% ∆clsB), and their growth rate was not affected, except when grown at 100 and 200 mM NaCl. Additionally, the root colonization capacity of both mutant strains was impaired compared with that of the wild type. Concomitant with the deletion of clsA and clsB genes, some physiological changes were observed in the UM270 ∆clsA and UM270 ∆clsB mutants, such as a reduction in indole acetic acid and biofilm production. By contrast, an increase in siderophore biosynthesis was observed. Further, inoculation of the UM270 wt strain in tomato plants (Solanum lycopersicum) grown under salt stress conditions (100 and 200 mM NaCl) resulted in an increase in root and shoot length, chlorophyll content, and dry weight. On the contrary, when each of the mutants were inoculated in tomato plants, a reduction in root length was observed when grown at 200 mM NaCl, but the shoot length, chlorophyll content, and total plant dry weight parameters were significantly reduced under normal or saline conditions (100 and 200 mM NaCl), compared to UM270 wt-inoculated plants. In conclusion, these results suggest that CL synthesis in P. fluorescens UM270 plays an important role in the promotion of tomato plant growth under normal conditions, but to a greater extent, under salt-stress conditions.

Improvement the activities of plant growth-promoting rhizobacteria in root-knot nematode Meloidogyne javanica and tomato plant growth in Wasit Province

This study had been conducted to detect the existence and dispersal of bacteria in the agricultural area in Wasit province and the role of them in controlling root knote nematode .Two genera of bacteria Azotobacter and Pseudomonas were isolated from six locations in Wasit province which were Alsiwarah , Alnuamania , Alahrar , Alhay , Alkut and Algardhia with five isolates of Azotobacter and eight isolates of Pseudomonas . The infectivity study of five Azotobacter isolates revealed that there is a significant differences between the isolates comparing with the control in reduction eggs hatching and the more effective isolates was Azotobacter sp1 ( Az1) with inhibition percentage 95.05% followed by the isolate Azotobacter sp2 (Az2 ) 84.32%. while the study of eight Pseudomonas isolates revealed that the more effective isolates was Ps eudomonas fluorescens2 ( Ps2) ) with inhibition percentage 90.16% and the lowest percentage recorded in the case of the isolate P. fluorescens6 ( Ps6) which was 55.76% . The infectivity study of four selective bacterial isolates (Az1, Az2, Ps1 , Ps2 ) with the fungus Glomus against nematode revealed the highest percentage of reduction in root galling recorded when the tomato plants inoculated with the fungus and the two bacterial isolates( Az1) , ( Ps2) and the number of galls were 3 galls/gm roots comparing with the control 10.6 galls/gm roots and the percentage of reduction 71.69 follwed by the treatment with the fungus and the two bacterial isolates( Az1) , ( Ps1) 68.86 %. The result also revealed that the combination between Glomus and bacterial isolates induced plant growth and increased the criteria of growth parameters. The result also revealed G lomus alone achieved percentage of reduction in root galling recorded when47.16% and the number of galls were 5.6 galls/gm roots comparing with the control 10.6 galls/gm roots.

Physiological and Nutritional Responses to Ozone Application in Tomato Seedling Plants

Research on environmentally friendly techniques for the agroindustry is growing constantly. In this sense, the supply of ozone (O3) has been taken into consideration, especially for disinfection because of its high oxidizing power. However, there is not enough information about the application of dissolved O3 via fertigation in crops. For that reason, in this study, two trials were carried out simultaneously to determine the consequences of O3 application on plant growth and quality of tomato plants. The first trial aimed to assess the effects on tomato fertigated with the nutrient solution and the application of O3. The second trial was performed to establish the ideal O3 supply rate for tomato plants. In both experiments, we measured the biometric, physiological, and nutritional parameters of the tomato plant. The results obtained showed that the application of O3 treatment resulted in the highest overall dry weight gain, whereas O3 application decreased leaf proline and total soluble sugars concentrations. There was no clear effect on chlorophyll and total soluble sugars in tomato plants under O3 application. Regarding nutritional parameters, the application of O3 led to a higher content of P and K in tomato plants. These findings indicate that the use of dissolved O3 via fertigation may present several advantages for tomato plants’ growth and quality.

Nematicidal activity of sweet annie and garden cress nano-formulations and their impact on the vegetative growth and fruit quality of tomato plants

Root-knot nematode is one of the major problems that face the agricultural production of several vegetable crops. Chemical nematicides have been banned because of their healthy and environmental undesirable attributes. So, this study aimed to evaluate the potential use of sweet annie (Artimisia annua) and garden cress (Lepidium sativum) as green routes for the development of effective and eco-friendly alternative nematicides. Nematicidal activity of sweet annie and garden cress aqueous extracts (500 g/L) in the original and nano-forms were evaluated against Meloidogyne incognita in tomato planted in infected soil under greenhouse conditions. Nineteen phenolic compounds were identified in A. annua extract, which was dominated by chlorogenic acid (5059 µg/100 mL), while 11 compounds were identified in L. sativum extract, that dominated by p-hydroxybenzoic acid (3206 μg/100 mL). Nano-particles were characterized with smooth surface, spherical shape and small size (50–100 nm). Under laboratory, the nano-formulations showed mortality percentage of M. incognita J2 greater than the original extract from. Vegetative growth parameters of tomato plants treated with A. annua and L. sativum extracts significantly improved compared to the control plants. Also, biochemical analysis revealed that the extracts were able to induce tomato plants towards the accumulation of phenolic compounds and increasing the activity of defensive enzymes (protease, polyphenol oxidase and chitinase) resulting in systemic resistance. Regarding tomato fruits yield and quality, the studied treatments significantly improved the yield and physicochemical parameters of tomato fruits in terms of fruit weight, diameter, TSS, pH, lycopene content and color attributes gaining higher sensorial acceptance by the panelist. Generally, both extracts represent promising nematicide alternatives and have potential use in crop management. The nano-form of A. annua extract outperformed the nematicidal activity of other studied treatments.

Fodder radish aqueous extracts and associated rhizobacteria as bio-stimulants on tomato growth

ABSTRACT Use of bio-stimulants can reduce amounts of synthetic chemicals for improving tomato (Solanum lycopersicum L.) growth and production. The investigation evaluated the rhizobacterial isolates B45, B46, B48, B54 and B55 associated with fodder radish (Raphanus sativus L.) and its aqueous extracts for their ability to promote growth of tomato plants under greenhouse conditions. Rhizobacteria were applied by root dipping followed by seedling drenching at planting. The isolates were characterized, based on macro-morphological and biochemical traits, and mechanisms involved in Plant Growth-Promoting (PGP) features were explored. For direct PGP traits, isolates were able to fix nitrogen on N-free agar medium. Isolates B45, B46, B54 and B55 were positive for indole-3-acetic acid production; isolates B46, B48 and B55 were positive for phosphate solubilization with the highest activity exhibited by B46. For indirect PGP traits, isolates were chitinase-, lipase-, and amylase-producing agents. Based on phylogenetic analysis of the 16S rDNA, the most bioactive isolate B46 was affiliated to Bacillus vallismortis (OK083726). All isolates displayed antifungal activity against soil-borne fungi Aspergillus niger, Penicillium digitatum, Fusarium oxysporum, F.sambucinum, and Trichoderma harzianum. Fodder radish aqueous extracts were tested at 5, 7.5, 10 or 15% (w:v). Chemical characterization by spectrophotometer of compounds indicated presence of auxin and polyphenols. Fodder radish aqueous extract displayed antifungal activity against all fungal species. Fodder radish appears to be a natural source for isolation of potent PGP rhizobacterial isolates and/or secondary metabolites bioactive for promotion of tomato growth and with an antifungal potential.

Comparative physiological and transcriptomics analysis revealed crucial mechanisms of silicon-mediated tolerance to iron deficiency in tomato.

Iron (Fe) deficiency is a common abiotic stress in plants grown in alkaline soil that causes leaf chlorosis and affects root development due to low plant-available Fe concentration. Silicon (Si) is a beneficial element for plant growth and can also improve plant tolerance to abiotic stress. However, the effect of Si and regulatory mechanisms on tomato plant growth under Fe deficiency remain largely unclear. Here, we examined the effect of Si application on the photosynthetic capacity, antioxidant defense, sugar metabolism, and organic acid contents under Fe deficiency in tomato plants. The results showed that Si application promoted plant growth by increasing photosynthetic capacity, strengthening antioxidant defense, and reprogramming sugar metabolism. Transcriptomics analysis (RNA-seq) showed that Si application under Fe deficiency up-regulated the expression of genes related to antioxidant defense, carbohydrate metabolism and organic acid synthesis. In addition, Si application under Fe deficiency increased Fe distribution to leaves and roots. Combined with physiological assessment and molecular analysis, these findings suggest that Si application can effectively increase plant tolerance to low Fe stress and thus can be implicated in agronomic management of Fe deficiency for sustainable crop production. Moreover, these findings provide important information for further exploring the genes and underlying regulatory mechanisms of Si-mediated low Fe stress tolerance in crop plants.

The effects of N-NO3: N-NH4 ratios and calcium concentration of the nutrient solution on the growth parameters and partitioning of nitrogen and calcium in tomato plants (Solanum lycopersicum L.)

Calcium (Ca) and nitrogen (N) are essential elements for plant growth; however, the N form ratio in the nutrient solution affects plant growth as well as the uptake and partitioning of other nutrient elements differently. This experiment was conducted to determine the effects of different N-NO3: N-NH4 ratios and calcium levels on calcium movement, partitioning, and N metabolism in tomato (Solanum lycopersicum) plants. Nitrogen was applied at four N-NO3: N-NH4 ratios (NR1 = 100:0, NR2 = 75:25, NR3 = 50:50, NR4 = 25:75) and Ca at three levels (80, 160, and 320 mg/l) using hydroponic culture. A factorial experiment was conducted in a greenhouse at the Isfahan University of Technology Research Center using a completely randomized design with four repetitions, three plants in each replication. The results showed that the Ca application decreased shoot length, but increased shoot diameter. Elevation of Ca concentration in the nutrient solution by 320 mg/l Ca treatment increased total amino acid, protein, yield, and Ca content of the fruit, but suppressed the nitrogen content of the shoot, root, and fruit. The highest nitrate and ammonium contents of tomato plants were in NR1 and NR2 treatments, respectively. With increasing the level of Ca, the concentration of Ca increased in the apoplast and xylem sap, but decreased in the symplast. The results showed that the NO3: NH4 ratio significantly affected the growth and calcium partitioning of tomato plants. The NO3: NH4 ratio of 75:25 corresponding to 320 mg/l of Ca improved yield and Ca movement to the distal of tomato fruit, resulting in preventing blossom-end rot and the best fruit quality.

Uji Kemampuan Trichokompos Dalam Menekan Penyakit Layu Fusarium Pada Tanaman Tomat

Fusarium wilt is one of the deadly diseases on tomato plants that need to be controlled.Trichocompost is compost containing the antagonistic fungus Trichoderma sp., which increasessoil fertility and controls plant pathogens. This study aimed to examine the effect of trichocompostdoses on: (1) the growth and yield of tomato plants, (2) the incidence of fusarium wilt, and (3) theseverity of fusarium wilt disease in tomato plants.This research was conducted at the Laboratoryof Plant Diseases and Greenhouses of Faperta Undana from March 2021 to August 2021. Thisstudy used a Randomized Block Design consisting of seven treatments repeated three times, sothere were 21 experimental units. The treatments tried were Trichocompost 25 g/polybag twoweeks before F. oxysporum inoculation, Trichocompost 50 g/polybag two weeks before F.oxysporum inoculation, Trichocompost 75 g/polybag two weeks before F. oxysporum inoculation,Trichocompost 25 g/polybag two weeks after F. oxysporum inoculation, Trichocompost 50g/polybag two weeks after inoculation of F. oxysporum, Trichocompost 75 g/polybag two weeksafter inoculation of F. oxysporum, andInoculation of F. oxysporum at planting withouttrichocompost application. The results showed that: (1) Trichocompost 75 g/polybag applied twoweeks before Fusarium oxysporum inoculation was able to increase plant height, the number ofleaves, and the number of tomato fruits, (2) Trichocompost applied two weeks before and afterinoculation of Fusarium oxysporum was able to reduce the incidence of fusarium wilt, (3)Trichocompost 75 g/polybag, applied two weeks before Fusarium oxysporum inoculation, reducedthe severity of fusarium wilt and was included in the category of high control effectiveness.

Polysaccharides combined to copper and magnesium improve tomato growth, yield, anti-oxidant and plant defense enzymes

The search for sustainable technologies to increase yield are fundamental for a modern agriculture. Polymers of biological origin (e.g., polysaccharides) have been studied for their potential use in agriculture. These substances present a great possibility of agricultural uses allowing their combination with nutrients to improve the uptake by plants. In this regard, the association of copper and magnesium to polysaccharides was investigated in the tomato cultivation in pots conducted with fertigation under protected environment. Two experiments were conducted: (i) foliar application of polysaccharides and their association with copper and magnesium in the initial growth of tomato plants; and (ii) tomato yield with foliar application of polysaccharides and their association with copper and magnesium. Growth, leaf nutrient content, enzymes and biochemical variables, fruit yield and leaf disease severity index were analyzed. The foliar sprays with polysaccharides in the combination with copper and magnesium was efficient to promote plant growth and yield. It also improved the concentration of antioxidant enzymes and the β,1,3 glucanase enzyme, while reducing the severity of powdery mildew in tomato leaves.

UV-C seed priming improves tomato plant growth against salt stress

The study aimed to evaluate the impact of UV-C dry seed priming at two doses (0.85 and 3.42 kJ.m−2), on tomato under salt stress (NaCl, 100 mM). Results show that salinity causes a regression of tomato growth by 63%, an accumulation of Na+ causing a reduction in K+ uptake and therefore an increase of photosynthetic processes (28, 28 and 23% for Chl. a, Chl. tot and Car., respectively), also an augmentation in soluble protein contents and a decrease or an increase in oxidative stress indicators and secondary metabolites depending on organs. UV-C seed priming has been shown to improve tomato growth by reducing the adverse effects of salinity on physiological and biochemical parameters. This research revealed that UV-C seed applications are an efficient approach to controlling the aggressiveness of salt stress on tomato roots and leaves. Specific doses of UV-C are required to trigger the physiological control of plants against salt stress.

Improving production and fruit quality of tomato under abiotic stress: Genes for the future of tomato breeding for a sustainable agriculture

Climate change and a rising world population make generation of crops with enhanced abiotic stress tolerance and higher nutritive value a priority objective in agriculture. In this review we have summarized recent advances on tomato ( Solanum lycopersicum ), the most important horticultural species regarding production and nutritional quality. Firstly, the different and complex processes evolved in abiotic stress tolerance are summarized, with special attention on responses to osmotic, oxidative and ionic and nutritional stress, as well as the anatomical changes involved in plant adaptation to abiotic stress. In order to avoid or reduce production loss and improve fruit quality under abiotic stress, it is of utmost importance the identification of tomato key genes involved in abiotic stress long-term tolerance, that is, genes which simple variation determines a significant change not only in vegetative but also in reproductive growth. The functions of the tomato genes known to date affecting fruit yield under abiotic stress are described, including those involved in signal sensing, perception and transduction of abiotic stress, transcription factors and abiotic stress responsive genes. Together with production, fruit quality is crucial in tomato given its so high worldwide consumption per capita . Nutritional compounds as carotenoids and vitamin E are well known antioxidants and abiotic stress induces a secondary oxidative stress to which plants have to react. Although the increased metabolites production under abiotic stress may be due to physiological adaptation processes, advances in this field will go in parallel to the identification of genes improving fruit quality when the plant is grown subjected to stressful conditions. The key genes involved in improvement of nutritional quality of tomato fruit under abiotic stress are reviewed, in particular the main ones involved in accumulation of crucial metabolites in this aspect, such as carotenoids and tocopherols. One of the main bottlenecks in breeding programs nowadays is the strong reduction of phenotypic and genetic diversity in modern germplasm. Therefore, searching of new genetic resources for improvement of abiotic stress tolerance and fruit quality is critical, including sources of natural variation, like wild relatives and traditional varieties or landraces, as well as spontaneous and induced mutants with beneficial effects on these traits. All of them will expand our knowledge on the processes involved in abiotic stress tolerance and fruit quality in tomato. • Adaptation strategies essential to uphold growth through plant life cycle in stress • Long-term stress tolerance genes are critical to reduce yield losses • Increasing fruit quality when growing tomato plants under abiotic stress conditions • Finding new genetic resources for improvement of tomato fruit yield and quality

Effect of micro–spray on plant growth and chlorophyll fluorescence parameter of tomato under high temperature condition in a greenhouse

Micro–spray is usually used to improve plant growth environment to avoid growth inhibiting and yield decreasing due to the high temperature inside the greenhouses in summer. To investigate the effect of micro–spray on plant growth and physiological properties, a combined irrigation method of micro–spray and drip irrigation (MSDI) was applied to tomato plants growing in a Venlo–type greenhouse for two seasons. The plant growth and physiological parameters of tomatoes grown under MSDI were compared with them under drip irrigation (DI). The running time of micro–spray was set based on the timing of high air temperature (Ta) appeared. The micro–spray was opened (7.5 L/h for each nozzle) for 1 min for each time point at 9:00, 10:00, 11:00, 12:00, 13:00 and 14:00 when the Ta was higher than 30 °C. The MSDI had a positive effect on plants growth (18% increased in stem diameter compared to DI) and the leaf temperature (Tl) decreased around 3–6 °C when the micro–spray was operated, and the cooling effect can be sustained for 10–30 min. Water use efficiency (WUE) under MSDI was similar to it under DI by comparing yield and total water consumption of tomato plants, and the total soluble solids (TSS) of tomato under two irrigation methods were similar (5.4% under DI and 5.5% under MSDI) during 2021.The results shown that the photosynthetically active radiation (PAR) and Ta were represented a negative correlation with chlorophyll fluorescence parameter (the effective quantum yield of PSII, ФPSII). The ФPSII value of tomato under MSDI was higher than it under DI during the micro–spray operating period, and it was more stable during the high Ta period. The improvement rate of ФPSII at different intensity of PAR (at 9:30, 10:30, 11:30, 12:30, 13:30 and 14:30) was varied, and it had a unified decline at 12:30 at the highest Tl during two seasons. Short time (1minute) micro–spray application did not have a remarkable effect on the adjusting of the damage caused by heat stress once temperature over 35 °C. Applying MSDI for tomato plants grown in greenhouse is recommended to reduce the severe effect on plant growth and physiology by high temperature. In addition, the result of this study provides a scientific guide for the development of intellectualization irrigation systems.

An effective stem water potential estimation method in tomato plant growth model for more precise digital fruit simulation incorporating microclimate and realistic plant management

ISHS XXXI International Horticultural Congress (IHC2022): International Symposium on Integrative Approaches to Product Quality in Fruits and Vegetables An effective stem water potential estimation method in tomato plant growth model for more precise digital fruit simulation incorporating microclimate and realistic plant management