Vegetative Growth Of Tomato Plants Research Articles

Development of Zn biofertilizer microbeads encapsulating Enterobacter ludwigii-PS10 mediated alginate, starch, poultry waste and its efficacy in Solanum lycopersicum growth enhancement

In the present farming era, rhizobacteria as beneficial biofertilizers can decrease the negative effects of Zinc (Zn) agrochemicals. However, their commercial viability and utility are constrained by their instability under field conditions. Thus, to enhance their stability, microbial formulations are considered, which will not only offer an appropriate microenvironment, and protection but also ensure a high rate of rhizospheric-colonization. The goal of this study was to create a new formulation for the Zn-solubilizing bacteria E. ludwigii-PS10. The studied formulation was prepared using the extrusion technique, wherein a composite solution containing alginate, starch, zinc oxide, and poultry waste was uniformly mixed with the bacterial strain PS10 to develop low-cost, eco-friendly, and slow-release microbeads. The produced microbead was spherical, and characterized by SEM, FTIR, and XRD. Further, the microbeads were analyzed for their survival stability over 3 months of storage at room temperature and 4 °C. The effect of the microbead on the vegetative growth of tomato plants was investigated. Results showed that 94 % of the encapsulated microbial beads (EMB) matrix was able to encapsulate the bacterial strain PS10. The dried EMB demonstrated a moisture content of 2.87 % and was able to preserve E. ludwigii-PS10 survival at room temperature at the rate of 85.6 %. The application of the microbead to the tomato plants significantly increased plant biomass and Zn content. As a result, our findings support the use of this novel EMB prepared using an alginate/poultry waste/starch mixture to increase bacterial cell viability and plant growth.

Endophytic Bacillus subtilis SR22 Triggers Defense Responses in Tomato against Rhizoctonia Root Rot.

Rhizoctonia root rot is one of the most destructive diseases of tomato and other crops. The biocontrol of plant diseases using endophytic bacteria has gained significant attention due to their distinct advantages compared with the free-living ones, as well as their new unexplored and unique properties. Endophytic Bacillus subtilis SR22 represents a promising and more effective biocontrol and growth-promoting agent for tomato plants than the free-living agents, being an ecofriendly and sustainable tool in modern agriculture. In this study, the direct antagonistic activity of B. subtilis SR22 was investigated against Rhizoctonia solani in vitro. The biocontrol activity of B. subtilis SR22 against Rhizoctonia root rot of tomato was also investigated. Effects on the level of the transcriptional expression of defense-related genes, biochemical responses, and the vegetative growth of tomato plants were also studied. The dual culture test showed 51% inhibition in the mycelial growth of R. solani due to B. subtilis SR22, indicating its potent antagonistic behavior. Using a GC-MS analysis, twenty bioactive compounds were detected to be produced by B. subtilis SR22, including chlorogenic acid, pyrrolo [1,2-a]pyrazine-1,4-dione, hexahydro, propyl thioglycolic acid, phthalic acid, and 2,3-butanediol. Under greenhouse conditions, the application of B. subtilis SR22 led to a reduction (up to 51%) in Rhizoctonia root rot of tomato. Furthermore, an upregulation in the expression of the responsive factor JERF3 (10.9-fold) and the defense-related genes POD (9.1-fold) and PR1 (4.5-fold) in tomato plants was recorded due to the application of B. subtilis SR22. In addition, this treatment enhanced the total phenolic content (76.8%) and activity of the antioxidant enzymes POD (56%) and PPO (29.2%) in tomato roots, indicating its resistance-inducing effect on tomato plants. Moreover, this treatment enhanced most of the evaluated growth parameters in tomato plants (up to 35%). We can conclude that B. subtilis SR22 is a promising biocontrol agent and growth promoter in tomato plants against Rhizoctonia root rot. An evaluation of the formulation and field application of this bio-agent is necessary in future studies.

اثر روش‌های مختلف پیوند بر رشد رویشی و عملکرد میوه گوجه‌فرنگی رقم "اس‌وی 8320"

Introduction: Today in order to produce vegetable fruits tolerant to adverse environmental conditions and increase growth, yield and fruit quality, grafting methods have been created. Tomato (Solanum lycopersicum) is one of the most important greenhouse products. Heirloom tomato cultivars lack disease genetic resistance and are particularly susceptible to epidemics in the field. Grafting can be used to unite the soil borne disease resistance and enhanced vigor of hybrid tomato cultivars with the high fruit quality of heirloom cultivars. There are deficiencies in vegetable grafting including skills for grafting operation performance and after the grafting, having enough knowledge to select rootstock, farm management in application of required fertilizers, graft incompatibility, excessive vegetative growth of grafting plant and physiological abnormalities, and fruit quality reduction. For grafting herbaceous plants such as vegetables, depending on the type of plant, plant size, grafting purpose, available equipment, preference and experience of the grafting plant producer and post-grafting management, different grafting methods have been introduce which is for different species and the used method is completely different. Each method has its own advantages and disadvantages, which are effective in the survival and development of grafting plants. This experiment was conducted in order to evaluate the effect of grafting methods on yield and vegetative growth of tomato plants. Material and Methods: Three common grafting methods, splice, cleft and approach grafting were evaluated for tomato SV 8320 cultivar grafted on Rimac rootstock. Executive operations were conducted in a completely randomized design with three replications at greenhouse of Lorestan Agriculture Faculty. Plant height, number of auxiliary shoot, number and length of internodes, number of fruit cluster, number of flower in cluster, root fresh and dry weight, number of fruit cluster, number of fruit in cluster, width and diameter of fruit, fruit weight, fruit fresh and dry weight, length of fruit tail, fruit tissue firmness, total soluble solid, pH, diameters of hypocotyl, pre, middle and total yield , ratio of the marketable fruits to second degree fruits, and fruit tissue firmness were recorded. Data was analyzed using SPSS software and means were compared by Duncan’s multiple range test. Results and Discussion: Grafting method had significantly effect on plant height, number and length of internode, root fresh and dry weight, number of fruit cluster, width and diameter of fruit, fruit weight, fruit fresh and dry weight, length of fruit tail, fruit tissue firmness, pH, pre, middle and total yield, the ratio of the marketable fruits to second degree fruits at 5% of probability level. Vegetative characteristics and yield in grafted plants were higher compared to non-grafted plants. Conclusion: According to results of this experiment using different grafting methods lead to stimulate growth in grafting plants, increasing production and product quality. Changes caused by the rootstock are controlled through water absorption, synthesis and transition of water, minerals and herbal hormones. Signal generation in the rootstocks and transition of them to the scion, causes changes in the physiology and morphology of the grafted plant. Grafting success varied between grafting methods, so that splice grafting is better than other methods. Graft compatibility was shown by the ability of tissue to regenerate and the vessels ability in wound tissues to rejoint together then grow and develop as a vigorous composite plant. Attempts to increase the productivity of grafted plant should be followed by the application of good agricultural practices.

Effect of Abscisic acid and Selenium foliar sprays on drought mitigation in tomato (Solanum lycopersicum L.)

Abscisic acid (ABA) and Selenium (Se) have been reported to alleviate the effect of abiotic stress especially drought in several plant species. Thus, this study aimed to compare the influence of foliar spray of ABA (0 and 100 µM) and Se (0 and 50 µM) on tomato plants grown under simulated drought stress at 0% soil field capacity (SFA). The obtained results based on physiochemical and antioxidant mechanism involving defense enzymes such as catalase, superoxide dismutase, ascorbate peroxidase and glutathione reductase revealed that ABA was potentially restrained drought stress in tomato plants compared to Se. ABA treatment significantly improved the relative water content and chlorophyll levels of seedlings compared to control. This represents the essential role of ABA on stress retrieval under drought conditions. In addition, ABA treated plants unveiled less hydrogen peroxide compared to control plants. This indicates the enhanced antioxidant mechanisms in ABA treated plants which consequently neutralized the hydrogen peroxide. In contrast, proline level was decreased in treated plants compared to control showed the diminished oxidative stress which simultaneously reduced the accumulation of proline. Overall, ABA protected tomato seedlings from the drought induced oxidative stress and promoted plant growth and development. Therefore, the present study suggests that the ABA foliar spray is more preferable to enhance the vegetative growth of tomato plants under water deficit condition.

Rizobacterias aisladas de Jatropha curcas L.: actividad antagonista de fitopatógenos y promotora del crecimiento de plantas

Introduction:Jatropha curcas L. is a species native to Mexico that has recently been considered an important crop to produce biofuel. Objective: To isolate and identify rhizobacteria from J. curcas with antagonistic activity against phytopathogenic fungi (Curvularia lunata and Fusarium equiseti) of this crop and evaluate their capacity to promote tomato plant growth. Materials and methods: The isolates were obtained by serial dilution and antagonistic activity was assessed by volatile and diffusible compounds on PDA medium. In addition, the production of antifungal compounds and metabolites that promote the plant growth were determined. The isolates were identified by amplifying the 16S RNA and sodA genes. Finally, the isolates were inoculated on tomato seeds to evaluated plant growth promotion and germination. Results and discussion: The antagonistic bacteria were identified as Bacillus mojavensis, Bacillus subtilis, Bacillusthuringiensis, and Pseudomonas aeruginosa. The antifungal effect on the mycelial growth of C. lunata and F. equisetiwas due to the presence of volatile and diffusible compounds with between 30 % and 79 % inhibition. Pseudomonas aeruginosa showed the strongest inhibitory effect (48.7 to 79.8 %). Bacillus subtilis (A1), B. mojavensis (A4) and B. thuringiensis (A6, A8) showed the highest germination (70 % to 88 %). The vegetative growth of tomato plants treated with the isolates was significantly higher than the controls(P < 0.05). Conclusion: Eight rhizobacteria isolated from J. curcas showed antagonistic activity against C. lunata and F. equiseti and demonstrated their capacity to improve the germination and promote growth in tomato plants

PENGARUH KOMBINASI DOSIS KOMPOS GULMA DAN PUPUK SINTETIK TERHADAP PERTUMBUHAN DAN HASIL TANAMAN TOMAT (Lycopersicum esculentum Mill.)

[EFFECT OF WEED COMPOST AND SYNTHETIC FERTILIZER DOSAGE ON TOMATO GROWTH AND YIELD (Lycopersicum esculentum Mill.)]. The growth and yield of tomato plants are influenced by fertilizer and nutrient content in the soil. This study aims to investigate the effect of a combination of synthetic fertilizer and weed compost on the growth and yield of tomato plants. The study was conducted in November 2016 through June 2017 in Agronomy, Faculty of Agriculture, University of Bengkulu, at an altitude of ± 10 m above sea level using a Completely Randomized Design (CRD). The treatments consisted of synthetic fertilizer at a rate of 180 kg/ha N, 150 kg/ha P2O5 and 100 kg/ha K2O (control), grass compost 30 , 40 and 50 tons/ha, 50% control + grass compost 15 tons/ha, 50% control + 20 tons/ha grass compost and 50% control + 25 tons/ha grass compost. The results revealed that the vegetative growth of tomato plants fertilized with grass compost 30 tons/ha and a combination of grass compost + 50% control did not differ from control treatment. Tomato yield fertilized with grass compost 30 tons/ha and a combination of 50% control + 15 tons/ha grass compost was higher than the control treatment. Therefore, 15 tons/ha of grass compost can reduce the dose of synthetic fertilizer by 50%.

Tomato SlERF.A1, SlERF.B4, SlERF.C3 and SlERF.A3, Members of B3 Group of ERF Family, Are Required for Resistance to Botrytis cinerea.

The Ethylene-Responsive Factors (ERFs) comprise a large family of transcriptional factors that play critical roles in plant immunity. Gray mold disease caused by Botrytis cinerea, a typical necrotrophic fungal pathogen, is the serious disease that threatens tomato production worldwide. However, littler is known about the molecular mechanism regulating the immunity to B. cinerea in tomato. In the present study, virus-induced gene silencing (VIGS)-based functional analyses of 18 members of B3 group (also called Group IX) in tomato ERF family were performed to identify putative ERFs that are involved in disease resistance against B. cinerea. VIGS-based silencing of either SlERF.B1 or SlERF.C2 had lethal effect while silencing of SlERF.A3 (Pit4) significantly suppressed vegetative growth of tomato plants. Importantly, silencing of SlERF.A1, SlERF.A3, SlERF.B4, or SlERF.C3 resulted in increased susceptibility to B. cinerea, attenuated the B. cinerea-induced expression of jasmonic acid/ethylene-mediated signaling responsive defense genes and promoted the B. cinerea-induced H2O2 accumulation. However, silencing of SlERF.A3 also decreased the resistance against Pseudomonas syringae pv. tomato (Pst) DC3000 but silencing of SlERF.A1, SlERF.B4 or SlERF.C3 did not affect the resistance to this bacterial pathogen. Expression of SlERF.A1, SlERF.A3, SlERF.B4, or SlERF.C3 was induced by B. cinerea and by defense signaling hormones such as salicylic acid, methyl jasmonate, and 1-aminocyclopropane-1-carboxylic acid (an ethylene precursor). SlERF.A1, SlERF.B4, SlERF.C3, and SlERF.A3 proteins were found to localize in nucleus of cells and possess transactivation activity in yeasts. These data suggest that SlERF.A1, SlERF.B4, and SlERF.C3, three previously uncharacterized ERFs in B3 group, and SlERF.A3, a previously identified ERF with function in immunity to Pst DC3000, play important roles in resistance against B. cinerea in tomato.

Effect of Soil Solarization on Soil Borne Fungi, the Growth and Yield of Tomato Grown In Clay Loam Soil at Alexandria Governorate, Egypt

Mulching by 100 µ thickness transparent plastic sheets compared with specific fungicides for controlling soil borne fungi were carried out at Al-Sabahia, Horticulture Research Station, Alexandria Governorate, Egypt. Solar heating resulted from mulching gradually reduced the tested soil borne-fungi to very low levels, comparable with non-mulched treatment. Soil Temperature, fungal frequency and tomato yield were recorded during the experimental seasons. The results indicated that there were no significant differences between the three months mulching and specific fungicides treatments effect against soil borne fungi. So, it could be concluded that possibility of using mulching method to control soil-borne diseases pathogens in the clay loam soil by planting the crop in solarized fields. The results also proved significant effect of the soil solarization on the vegetative growth of tomato plants and enhanced the yield and its components compared with the control. The results for the total yield per feddan proved that there were no significant differences between the treated root with fungicide and the three month soil solarization treatments in both seasons. The percentages increase in the estimated total yield per feddan were 21.40, 18.95, 12.40 and 3.11% for treated root with fungicide, three, two and one month treatments over the control, respectively in 2014 season, whereas, they were 25.65, 22.51, 16.40 and 9.52% for the same treatments, respectively in the 2015 season.

Comparison of Morphological Characteristics of Twelve Cultivars of Tomato Determinate Plants and Their Impact on Yield and its Structure

Comparison of Morphological Characteristics of Twelve Cultivars of Tomato Determinate Plants and Their Impact on Yield and its Structure Experiment took place in the open field in the Vegetable Experimental Station of Agricultural University near Cracow in the years 2008-2010. In the experiment twelve, polish-bred determinate tomato cultivars: Sokal F1, Batory F1, Rejtan F1, Hetman F1, Babinicz, Luban, Mieszko F1, III A F1, Awizo F1, Ondraszek, Talon and Hubal were used. In the end of growing season, morphological features of plant were measured, concerning: height of plant, number of lateral shoots, length and thickness of the internode and the number of inflorescences per plant. Harvesting was performed once, at the stage of maturity of individual cultivars. The yield and its structure was calculated. The results were statistically analyzed using NIR Fisher's test, with p=0.05. The dependences of the marketable yield and total yield of tomato plants from morphological characteristics that may affect the yield were analyzed, using multiple regression. The amount of total and marketable yield was negatively correlated with an extensive vegetative growth of tomato plants. Among all the tested cultivars Ondraszek was characterized by the most preferred morphological features and creates one of the highest yields. Cultivars Ondraszek, Sokal F1 and Batory F1 were characterized higher marketable yield, than ‘Hetman F1’. Total and marketable yield depended about 40% on tomato plant morphological features.

THE INFLUENCE OF ELECTRO KINETIC NUTRIENT TREATMENT SYSTEM USING BAKUHAN-SEKI ON VEGETATIVE GROWTH OF TOMATO

To produce a quality tomato (Lycopersicon esculentum), it is necessary to have a quality environment. Greenhouses are widely employed to create a favourable environment for growing tomatoes, both with soil and soilless cultivation techniques. It is natural to endeavour a properly planned layout to make the best possible use of the available natural resources, but at the same time ensuring the environment for the growing plants is conducive to high yield and quality. In this study an innovative nutrient treatment system in which Bakuhan-seki, a silicate mineral fluidized in nutrient solution was attempted. The nutrient solution was pumped from the nutrient tank through the lower to the upper side of the fluidization layer, in order to return to the tank again. This activates nutrient through the electro chemical energy of the minerals fluidized in a circling current. In the activation of nutrient solution, negative charges on the surface of Bakuhan-seki caused pH-buffer and ion exchange actions. The benefits of activated water have been demonstrated by extensive experimental works. Moreover when nutrient solution passed on the surface of silica, an electric double layer was formed between interfaces of silica and water giving negative and positive charges. Plants can absorb nutrient easily, promoting their growth and increasing their yield. For a detailed description of this relationship, the effects of fluidized nutrient solution on hydroponically grown tomatoes were investigated. The germination rate was tendentiously enhanced, and the early growth of seedlings was significantly improved by using treated nutrient solution. Additionally, the fluidization of nutrient solution caused an increase in shoot and root length, stem diameter, shoot and root weight and SPAD value of tomato plants. As all desirable characteristics in the produced plants increased when exposed to electro kinetic treatment, the treatment itself constitutes an alternative method to improve vegetative growth of tomato plants.

Produção de cultivares de tomateiro em hidroponia e fertirrigação sob razões de nitrogênio e potássio

Os cultivos protegidos de tomate apresentam elevada demanda por potássio para altas produções e qualidade de frutos, não tendo sido estudada suficientemente a relação de aplicação entre nitrogênio e potássio que proporcione tais resultados. Avaliou-se a produção e qualidade de frutos de quatro cultivares de tomateiro em sistemas de cultivo hidropônico e fertirrigado sob duas razões entre N e K fornecidas às plantas. Dois experimentos foram conduzidos simultaneamente em casa de vegetação, em esquema fatorial 4x2 com quatro repetições, combinando quatro genótipos (cvs. Cereja 261, San Marzano, Santa Clara e o híbrido Cereja Chipano) com duas razões N:K (1:1,5 e 1:2 no hidropônico, e 1:2 e 1:3 no fertirrigado). A produção média de frutos comerciais foi de 2,5 e 1,8 kg/planta no sistema hidropônico e fertirrigado, respectivamente, atingindo 3,3 kg/planta na cv. Santa Clara em hidroponia. Em hidroponia, as razões N:K não afetaram a produção de frutos comerciais e o teor de sólidos solúveis, apesar de um aumento de 6,5% na produção na razão N:K 1:2. A razão N:K 1:2 em hidroponia aumentou a massa e o diâmetro médio dos frutos comerciais, reduzindo a concentração de K nos frutos. No sistema fertirrigado, a razão N:K 1:3 estimulou o crescimento vegetativo do tomateiro, mas não afetou a produção e a qualidade dos frutos. As cultivares San Marzano e Santa Clara tiveram maior produção de frutos nos dois sistemas. A produção de frutos e o teor de sólidos solúveis das cvs. San Marzano e Santa Clara foram maiores no sistema hidropônico em comparação ao fertirrigado. O sistema hidropônico propiciou maior produção de frutos que o sistema fertirrigado para as cultivares San Marzano e Santa Clara e, em hidroponia a razão N:K 1:2 forneceu frutos de maior qualidade comercial.

Observations on the suppression of root-knot nematode ( Meloidogyne arenaria) on tomato by incorporation of cyanobacterial powder ( Oscillatoria chlorina) into potting field soil

Experiments were carried out to investigate the nematicidal potential of a cyanobacterium, Oscillatoria chlorina, against the root-knot nematode, Meloidogyne arenaria on tomato plants grown in pots filled with 500 cm 3 of field soil infested with 12-s stage juveniles (J 2)/cm 3 soil. Incorporation of freeze-dried cyanobacterial powder into potted field soil at the rate of 0.2%, 0.4%, 0.6%, 0.8% and 1.0% (w/w) 5 days prior to tomato planting, reduced root galling, final population of M. arenaria and increased vegetative growth of tomato plants and root-mass production, compared with untreated control ( P ⩾ 0.05). The beneficial effect of adding cyanobacterial powder into infested potted field soil increased exponentially with concentration up to 0.8%. Root galling and nematode population decreased by 68.9% and 97.6%, respectively at the highest dose (1%) of cyanobacterial powder compared with the untreated control. Addition of cyanobacterial powder into infested potted field soil at 5 days before planting was the most effective followed by 2 days before and at the time of tomato planting. We conclude that application rate and timing are important factors in the control of root-knot nematodes with O. chlorina.

The predatory nematode, Mononchoides fortidens (Nematoda: Diplogasterida), suppresses the root-knot nematode, Meloidogyne arenaria, in potted field soil

Experiments were conducted to evaluate the effect of inoculum density and application time of the predatory nematode, Mononchoides fortidens, against the root-knot nematode, Meloidogyne arenaria, on tomato plants (Lycopersicon esculentum) cv. Pusa Ruby grown in pots containing 500 g field soil infested with 10 s stage juveniles (J2)/g soil. Addition of M. fortidens to pots at different concentrations (0, 50, 100, 150, 200, and 250 per pot) 7 days prior to tomato planting reduced root galling and the final population of M. arenaria and increased vegetative growth of tomato plants and root-mass production, compared with zero predators. The beneficial effect of adding predatory nematodes to infested potted field soil increased exponentially with concentration up to 200 nematodes per pot. Application of predatory nematodes 2 days after tomato planting was ineffective. Efficacy of predatory nematodes applied at the time of planting was intermediate between the treatments where predatory nematodes were added before and after tomato planting. At the end of the experiments, higher numbers of predators were recovered than were inoculated.

Early Vegetative Growth of Tomato Plants in Media Containing Nitrogen Source as Nitrate, Ammonium, or Various Nitrate–Ammonium Mixtures with Bicarbonate Addition

The effect of various concentrations applied in media with , , or various mixtures of both on the accumulation of biomass and early vegetative growth of tomato (Lycopersicon esculentum Mill.) plants was tested in experiments carried out in hydroponics. The optimum concentration was 5 mM and was similar in all the combinations of the N source applied at 3 mM concentration. The average biomass of -grown plants without reached only 50% of the value for the plants if was used as the N source. With respect to the growth without , the biomass increased by about 160% or 130% with or used as the N source, respectively. The biomass of -grown plants in media with reached only about 42% of the value obtained by plants cultivated in media with and . Similar relations were observed in the size of leaf blades. A simultaneous addition of to the medium containing ameliorated the toxic effects of this compound. The optimum ratio of for the growth of plants was ≤ 1. The use of such proportions of nitrogen (N) forms in the medium stimulated the accumulation of biomass to about 115% of the mass attained by -grown plants. The addition of to the medium containing the N source in the two forms at an optimum ratio stimulated an increase in the biomass of plants by about 180% with respect to plants without . Certain growth parameters calculated, i.e., shoot to root ratio, specific leaf area, and relative growth rate confirm the ameliorating effect of if added to media containing and the stimulating effect of on the biomass production of different organs of the plants.

Early Vegetative Growth of Tomato Plants in Media Containing Nitrogen Source as Nitrate, Ammonium, or Various Nitrate?Ammonium Mixtures with Bicarbonate Addition

Abstract The effect of various concentrations applied in media with , , or various mixtures of both on the accumulation of biomass and early vegetative growth of tomato (Lycopersicon esculentum Mill.) plants was tested in experiments carried out in hydroponics. The optimum concentration was 5 mM and was similar in all the combinations of the N source applied at 3 mM concentration. The average biomass of -grown plants without reached only 50% of the value for the plants if was used as the N source. With respect to the growth without , the biomass increased by about 160% or 130% with or used as the N source, respectively. The biomass of -grown plants in media with reached only about 42% of the value obtained by plants cultivated in media with and . Similar relations were observed in the size of leaf blades. A simultaneous addition of to the medium containing ameliorated the toxic effects of this compound. The optimum ratio of for the growth of plants was ≤ 1. The use of such proportions of nitrogen (N) forms in the medium stimulated the accumulation of biomass to about 115% of the mass attained by -grown plants. The addition of to the medium containing the N source in the two forms at an optimum ratio stimulated an increase in the biomass of plants by about 180% with respect to plants without . Certain growth parameters calculated, i.e., shoot to root ratio, specific leaf area, and relative growth rate confirm the ameliorating effect of if added to media containing and the stimulating effect of on the biomass production of different organs of the plants.

Diurnal uptake of nitrate and potassium during the vegetative growth of tomato plants

Abstract Tomato plants (Lycopersicon esculentum Mill.) of the F1 hybrid variety Turbo were grown in a NFT system for 22 days. On days 16 and 20–22 inclusive of the experiment, the diurnal variation in nitrate (NO3), potassium (K), and water uptake rates were measured. Nitrate and K uptake rates were subject to large diurnal variation with maximum uptake rates occurring during the day period. Two peaks of diurnal uptake rates were identified, one large peak during the day period and a second much smaller one during the first 2–4 hours of the night. Under the conditions of the experiment, night nutrition made up 35 to 40% of the total daily uptake of K and NO3. Water uptake rates followed a diurnal oscillation with a single peak pattern. Highest rates occurred at the middle of the photoperiod and lowest rates were measured at night. Over the entire day and night cycle there was no correlation between the rates of water and nutrient uptake. This may be of importance in the fertilization of hydroponically gro...