scholarly journals Computer-based System for Dynamic Control of Greenhouse Tomato Grown in NFT System

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 847F-847
Author(s):  
Mohamed Benmoussa ◽  
Laurent Gauthier
Keyword(s):  
Nutrient Solution ◽  
Dynamic Control ◽  
General Purpose ◽  
High Yield ◽  
Nutrient Concentrations ◽  
Greenhouse Tomato ◽  
Computer Based ◽  
And Control ◽  
Nutrient Solutions

To achieve high yield and better quality of soilless greenhouse tomato, it is necessary to keep the nutrient concentrations in the root environment at the target levels. Dynamic control of the nutrient solution composition can be used for this purpose. We developed a computer program that dynamically adjusts nutrient solution compositions based on various climatic and agronomic characteristics. The program integrates nutrient uptake and crop transpiration models and is part of a general-purpose greenhouse management and control software system developed at Laval University (GX). The architecture of the system and some simulation results comparing the effect of various control scenarios on the evolution of the composition of nutrient solutions are presented.

scholarly journals Modeling Nutrient Uptake and Prolonged Use of Nutrient Solutions in Soilless Tomato Culture

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 761F-761
Author(s):  
Mohamed Benmoussa ◽  
Laurent Gauthier
Keyword(s):  
Nutrient Uptake ◽  
Nutrient Solution ◽  
Climatic Factors ◽  
High Yield ◽  
Nutrient Concentrations ◽  
Factors Affecting ◽  
Nutrient Imbalances ◽  
Nutrients Uptake ◽  
Using Data ◽  
Nutrient Solutions

In soilless culture, the buffering capacity of the root environment for nutrients is low. This, combined with fluctuations of climatic factors and changes in nutrient uptake rates, can lead to nutrient imbalances. In order to achieve high yield and better quality, it is necessary to keep the nutrient concentrations in the root environment at the target levels. This requires frequent analysis and adjustments to the nutrient solution. Currently, leaching of the growing media or renewal of the nutrient solution is commonly used to avoid accumulation or depletion of nutrient in the root environment. However, this practice lowers the efficiency of fertilizers and can lead to the contamination of the ground water. One way to remedy to this problem is through the use of nutrients uptake models to track the composition of the nutrient solutions. The objective of this study was to develop such models. Such models can be used to maintain balanced nutrient solutions for longer periods. This can lead to reduced leaching and improved fertilizer use efficiency. Macronutrient (N, P, K, Ca, and Mg) uptake models were developed for tomato plants grown in an NFT system using data collected from experiments conducted in the Laval Univ. greenhouses. Analysis of the experimental results showed that the main factors affecting nutrients uptakes are light and transpiration.

scholarly journals Silicon attenuates calcium deficiency by increasing ascorbic acid content, growth and quality of cabbage leaves

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dalila Lopes da Silva ◽  
Renato de Mello Prado ◽  
Luis Felipe Lata Tenesaca ◽  
José Lucas Farias da Silva ◽  
Ben-Hur Mattiuz
Keyword(s):  
Ascorbic Acid ◽  
Nutrient Solution ◽  
Acid Content ◽  
Dry Matter ◽  
Ascorbic Acid Content ◽  
Calcium Deficiency ◽  
Ca Deficiency ◽  
Leaf Water Loss ◽  
Nutrient Solutions

AbstractCalcium (Ca) deficiency in cabbage plants induces oxidative damage, hampering growth and decreasing quality, however, it is hypothesized that silicon (Si) added to the nutrient solution may alleviate crop losses. Therefore, this study aims at evaluating whether silicon supplied in the nutrient solution reduces, in fact, the calcium deficiency effects on cabbage plants. In a greenhouse, cabbage plants were grown using nutrient solutions with Ca sufficiency and Ca deficiency (5 mM) without and with added silicon (2.5 mM), arranged as a 2 × 2 factorial in randomized blocks, with five replications. At 91 days after transplanting, the plants were harvested for biological evaluations. In the treatment without added Si, Ca deficiency promoted oxidative stress, low antioxidant content, decreased dry matter, and lower quality leaf. On the other hand, added Si attenuated Ca deficiency in cabbage by decreasing cell extravasation while increasing both ascorbic acid content and fresh and dry matter, providing firmer leaves due to diminished leaf water loss after harvesting. We highlighted the agronomic importance of Si added to the nutrient solution, especially in crops at risk of Ca deficiency.

scholarly journals Yield and Quality Characteristics of Brassica Microgreens as Affected by the NH4:NO3 Molar Ratio and Strength of the Nutrient Solution

Foods ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 677 ◽  
Author(s):  
Onofrio Davide Palmitessa ◽  
Massimiliano Renna ◽  
Pasquale Crupi ◽  
Angelo Lovece ◽  
Filomena Corbo ◽  
...  
Keyword(s):  
Nutrient Solution ◽  
Inorganic Ions ◽  
Molar Ratio ◽  
High Yield ◽  
Nitrate Content ◽  
Carotene Content ◽  
Molar Ratios ◽  
Half Strength ◽  
Nutrient Solutions ◽  
Β Carotene

Microgreens are gaining more and more interest, but little information is available on the effects of the chemical composition of the nutrient solution on the microgreen yield. In this study, three Brassica genotypes (B. oleracea var. italica, B. oleracea var. botrytis, and Brassica rapa L. subsp. sylvestris L. Janch. var. esculenta Hort) were fertigated with three modified strength Hoagland nutrient solutions (1/2, 1/4, and 1/8 strength) or with three modified half-strength Hoagland nutrient solutions with three different NH4:NO3 molar ratios (5:95, 15:85, and 25:75). Microgreen yields and content of inorganic ions, dietary fiber, proteins, α-tocopherol, and β-carotene were evaluated. Micro cauliflower showed the highest yield, as well as a higher content of mineral elements and α-tocopherol (10.4 mg 100 g−1 fresh weight (FW)) than other genotypes. The use of nutrient solution at half strength gave both a high yield (0.23 g cm−2) and a desirable seedling height. By changing the NH4:NO3 molar ratio in the nutrient solution, no differences were found on yield and growing parameters, although the highest β-carotene content (6.3 mg 100 g−1 FW) was found by using a NH4:NO3 molar ratio of 25:75. The lowest nitrate content (on average 6.8 g 100 g−1 dry weight) was found in micro broccoli and micro broccoli raab by using a nutrient solution with NH4:NO3 molar ratios of 25:75 and 5:95, respectively. Micro cauliflower fertigated with a NH4:NO3 molar ratio of 25:75 showed the highest dry matter (9.8 g 100 g−1 FW) and protein content (4.2 g 100 g−1 FW).

scholarly journals Determination of the Effect of Humic Acid on Growth and Development Parameters of Parsley (Petroselinum sativum Hoffm.) Grown in Boron Soil

2018 ◽  
Vol 47 (1) ◽  
pp. 183-193 ◽  
Author(s):  
Tuncay TURSUN ◽  
Sener AKINCI ◽  
Esin BOZKURT
Keyword(s):  
Humic Acid ◽  
Growth Parameters ◽  
Dry Weight ◽  
High Yield ◽  
Yield And Quality ◽  
Icp Ms ◽  
Growth Analyses ◽  
Nutrient Solutions

Boron is an important micronutrient, required for all plant growth, and critical for high yield and quality of crops. The aim of the present research was to determine the effects of boron on pot-grown parsley (Petroselinum sativum Hoffm.). The experimental design consisted of four treatments using Hoagland-Arnon (1950) nutrient solutions with two different boron concentrations (B1 - 15 ppm and B2 - 150 ppm), each with and without 10 ml humic acid addition (HB1 and HB2), and controls with full strength Hoagland-Arnon solutions. Growth analyses of the parsley revealed that 15 ppm boron application caused an increase in root length leaf fresh and dry weight root fresh and dry weight and leaf area compared to control values. 150 ppm B (B2) concentration decreased all growth parameters compared to controls. The two humic acid treatments (HB1 and HB2) did not increase any of those growth parameters either in controls (C) or in the two boron (B1 and B2) concentrations. Analysis by (ICP-MS) revealed that B content in the leaves increased gradually in B1 and B2, as well as in both humic treatments where in HB2 it increased to 99.38% compared to B1. In the leaves, Mn, Zn and Fe contents behaved the same as B, increasing in all treatments, with the amounts in HB2 being significantly greater than in C, B1 and B2 leaves.

scholarly journals A Novel Transportation Method Based on Dynamic Control of Ripening Environment

2020 ◽  
Vol 13 (5) ◽  
pp. 58-66
Author(s):  
Xinyu Liu ◽  
◽  
Xiaojie Jin
Keyword(s):  
Low Temperature ◽  
Fruits And Vegetables ◽  
Control Method ◽  
Volume Fraction ◽  
Dynamic Control ◽  
Exogenous Ethylene ◽  
Quality Of Products ◽  
And Control ◽  
Air Circulation

The dynamic control of atmosphere is an important factor for guaranteeing the quality of climacteric products during transportation. As atmosphere changes, respiration climacteric products would rot because of overripeness, thus leading to loss. Moreover, climacteric products must be ripened artificially when delivered to the destination, thereby causing economic waste. In this study, a new transportation method based on dynamic control of ripening environment was designed.The ripeness control method based on the dynamic control of ripening atmosphere was presented to accomplish quality safety during transportation as well as avoid a subsequent extra process of ripening. The transportation method was employed to stem from the ethylene’s ripening effect on climacteric fruits and vegetables. The ethylene generator and air circulation unit, which dynamically regulate and control the dual regional atmosphere of carriages during transportation, were quantitatively controlled by the central treatment layer. Ripeness level could be regulated by controlling the temperatures and time of exogenous ethylene release, to control the quality of products and ripen them. The proposed method was proven feasible through experiments. Results demonstrate that a volume fraction of 0.01% exogenous ethylene allows bananas’ respiratory intensity to reach the peak early; meanwhile, moderate low temperature (16 °C) can enable ethylene peak to appear in advance. Therefore, bananas’ ripeness can be controlled by changing temperatures and the ripening environment when transporting. This study can provide references for the control of products’ ripeness during transportation.

scholarly journals Effects of Varying Sulfate Concentrations on Growth and Mineral Nutrition of the Greenhouse Tomato

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 769C-769
Author(s):  
J. Lopez ◽  
L.E. Parent ◽  
N. Tremblay ◽  
A. Gosselin
Keyword(s):  
Nutrient Solution ◽  
Mineral Nutrition ◽  
Major Ions ◽  
Block Design ◽  
Dry Weight ◽  
Sulfate Ions ◽  
Tomato Plants ◽  
Greenhouse Tomato ◽  
High Concentrations ◽  
Nutrient Solutions

In hydroponic recirculating systems, sulfate ions can accumulate to excessive levels and interfere with other nutrient ions. The objective of this research was to determine the effects of four sulfate concentrations on growth and mineral nutrition of greenhouse tomato plants (Lycopersicon esculentum Mill. cv. Trust). Tomato seeds were sown in flats and subsequently transplanted into rockwool slabs. Ten days after transplanting, plants were given four sulfate concentrations in nutrient solutions (S0 = 0.1, S1 = 5.2, S2 = 10.4, and S4 = 20.8 mM). The plots were arranged in a randomized complete-block design with four replications. Treatment S0 reduced dry weight of the top portion of the plant. A sulfate shortage in the nutrient solution decreased S concentrations in the leaf and decreased fruit number. Activities and concentrations of major ions in solutions expressed in mM or as row-centered logratios were correlated with corresponding foliar concentrations expressed in grams of nutrient per kilogram of dry matter or as row-centered logratios. Data were presented in this manner in order to explore interactive models describing relationships between mineral composition of both nutrient solutions and plant tissues. High concentrations of sulfate ions in the nutrient solution up to 20.8 mM did not affect tomato growth or yield. Tomato plants appeared prone to sulfate deficiency, but tolerant to sulfate concentrations up to 20.8 mM in the nutrient solution.

scholarly journals Pembrolizumab microgravity crystallization experimentation

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Paul Reichert ◽  
Winifred Prosise ◽  
Thierry O. Fischmann ◽  
Giovanna Scapin ◽  
Chakravarthy Narasimhan ◽  
...  
Keyword(s):  
National Laboratory ◽  
Space Station ◽  
Bimodal Distribution ◽  
High Yield ◽  
Injectable Formulation ◽  
Crystallization Experiments ◽  
Delivery Options ◽  
And Control ◽  
Control Crystallization

AbstractCrystallization processes have been widely used in the pharmaceutical industry for the manufacture, storage, and delivery of small-molecule and small protein therapeutics. However, the identification of crystallization processes for biologics, particularly monoclonal antibodies, has been prohibitive due to the size and the flexibility of their overall structure. There remains a challenge and an opportunity to utilize the benefits of crystallization of biologics. The research laboratories of Merck Sharp & Dome Corp. (MSD) in collaboration with the International Space Station (ISS) National Laboratory performed crystallization experiments with pembrolizumab (Keytruda®) on the SpaceX-Commercial Resupply Services-10 mission to the ISS. By leveraging microgravity effects such as reduced sedimentation and minimal convection currents, conditions producing crystalline suspensions of homogeneous monomodal particle size distribution (39 μm) in high yield were identified. In contrast, the control ground experiments produced crystalline suspensions with a heterogeneous bimodal distribution of 13 and 102 μm particles. In addition, the flight crystalline suspensions were less viscous and sedimented more uniformly than the comparable ground-based crystalline suspensions. These results have been applied to the production of crystalline suspensions on earth, using rotational mixers to reduce sedimentation and temperature gradients to induce and control crystallization. Using these techniques, we have been able to produce uniform crystalline suspensions (1–5 μm) with acceptable viscosity (<12 cP), rheological, and syringeability properties suitable for the preparation of an injectable formulation. The results of these studies may help widen the drug delivery options to improve the safety, adherence, and quality of life for patients and caregivers.

scholarly journals Influence of the N/K ratio on the production and quality of cucumber in hydroponic system

Revista CERES ◽  
2011 ◽  
Vol 58 (5) ◽  
pp. 619-624 ◽  
Author(s):  
Adriene Woods Pedrosa ◽  
Herminia Emilia Prieto Martinez ◽  
Edson Marcio Matiello ◽  
Paulo Cezar Rezende Fontes ◽  
Paulo Roberto Gomes Pereira
Keyword(s):  
Nutrient Solution ◽  
Vegetative Growth ◽  
Additional Treatment ◽  
Fresh Weight ◽  
Hydroponic System ◽  
Randomized Design ◽  
Hydroponic Cultivation ◽  
Fruit Setting ◽  
Nutrient Solutions

The objective of this work was to evaluate the quality of fruits and the nutritional status of cucumber CV. Aodai cultivated in nutrient solutions with different N:K ratios. The hydroponic cultivation was initially performed, during the vegetative growth, in nutrient solution with 1:2.0 mmol L-1 N:K, and, later, during fruit setting, in four different nutrient solutions with N:K (w/w) at the ratios 1:1.4, 1:1.7, 1:2.0 and 1:2.5. An additional treatment with a nutrient solution containing the ratio 1:2.2 (w/w) N:K during the vegetative growth and N:K 1:1.4 (w/w) during fruit setting, both with 10% ammonium (NH4+) was included. The treatments were arranged in a randomized design with six replicates. Irrigation was carried out with deionized water until seed germination, and then with nutrient solution until 30 days after germination, when plants were transplanted. Plants in the hydroponic growing beds were irrigated with the solutions for vegetative growth, and, after 21 days, the solutions were replaced by solutions for fruit setting. At 45 and 60 days after transplanting, the fresh weight, length, diameter, volume and firmness of the fruit were evaluated, and, at 45 days after transplanting, the macronutrient concentrations in the leaves were determined. The use of different N:K ratios during fruit setting influenced the cucumber production. The ratio of 1.0:1.7 N: K (w/w), with 10% of N in the form of ammonia, is recommended for the whole cycle.

scholarly journals Current Fertilizer Input for Pot Gerbera Production Can Be Reduced by More than 50%

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 775D-775
Author(s):  
Youbin Zheng* ◽  
Thomas Graham ◽  
Stefan Richard ◽  
Mike Dixon
Keyword(s):  
Nutrient Solution ◽  
Crop Production ◽  
Negative Impact ◽  
Dry Weight ◽  
Flower Number ◽  
Leaf Chlorophyll ◽  
Phytotoxic Effect ◽  
Total Dry Weight ◽  
Nutrient Solutions

Pot gerbera (Gerbera jamesonii Var. `Shogun') plants were subirrigated with one of four nutrient solutions (10, 25, 50, and 100% of full strength) in order to determine whether currently used commercial nutrient solution concentrations can be reduced without negative impact on crop production. Nutrient concentration levels did not affect leaf area, flower number and appearance, and plant total dry weight. There were no significant differences in leaf chlorophyll content between the plants that received the 50 and 100% strength nutrient solutions. It is concluded that nutrient solution concentrations typically used in commercial greenhouse, for pot gerbera production, can be safely reduced by at least 50% without adversely affecting crop production. Nutrients accumulated in the top section of the growth substrate under all treatment levels; however, no phytotoxic effect was observed. Fertilizer inputs were reduced in the 50%, 25%, and 10% treatments by 54%, 75%, and 90% respectively. After 4 weeks recirculating, the quality of the nutrient solutions was still within acceptable limits.

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