scholarly journals 161 Using a Controlled Water Table Irrigation for Class Demonstrations of Plant Growth

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 470A-470
Author(s):  
J.W. Buxton ◽  
T. Phillips
Keyword(s):  
Plant Growth ◽  
Water Table ◽  
Nutrient Solution ◽  
Irrigation System ◽  
Nutrient Deficiency ◽  
Zn Deficiency ◽  
Nutrient Deficiencies ◽  
Poor Growth ◽  
Growing Media ◽  
Set Up

In class demonstrations, it is almost impossible to maintain the same water: air ratio in growing media. If some treatments result in greater plant growth than others, treatment effects on plant growth are often confounded with the effect of water: air ratio in the growing media. In a laboratory demonstration of nutrient deficiencies symptoms in plants, a controlled water table irrigation system maintained a constant water: air ratio in the growing media regardless of the nutrient deficiency affect on plant growth. The modified capillary mat irrigation system consists of one mat edge extending over the edge of the bench into a narrow trough on the side of the bench. The nutrient solution level in the trough is controlled by a liquid level controller, so it is at a fixed distance below the bench surface. The nutrient solution is drawn upward by capillarity to the bench surface and then moves by capillarity over the bench. The system automatically maintains a constant air: water ratio in the growing media. A standard Hogland solution was modified to demonstrate deficiencies in N, P, K, Mg, Ca, Cu, Fe, and Zn on corn, squash, radish, soybeans, and marigold. Seeds were germinated and grown to maturity in either a 10- or 15-cm pot. Students set up the demonstration, were provided instruction in preparing solutions, regularly observed plant growth, and answered questions at the end of the study about differences in plant growth observed. However, possibly because low concentrations of some minor elements in the capillary mat, Zn deficiency was not observed and other elements, although resulting in poor growth compared to the control, did not show severe deficiency symptoms.

scholarly journals 456 An Automatic, Controlled Water-Table Irrigation System for Vegetable Transplant Production

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 523C-523
Author(s):  
J.W. Buxton ◽  
Wenwei Jia
Keyword(s):  
Water Table ◽  
Nutrient Solution ◽  
Irrigation System ◽  
Growing Media ◽  
System A ◽  
Fixed Distance ◽  
Run Off ◽  
Vegetable Seed ◽  
Growth Of Seedlings ◽  
Water Ratio

The controlled water-table irrigation (CWT) system was evaluated for vegetable seed germination and transplant growth. The system is a modification of capillary mat irrigation except that the mat along one side extends over the edge of the bench into a narrow trough running along the side of the bench. The nutrient solution level in the trough is controlled by a liquid level controller, so it is at a fixed distance below the bench surface. The nutrient solution is drawn by capillarity from the trough upward to the bench surface and then moves by capillarity to the opposite side of the bench. The system automatically maintains a constant air: water ratio in the growing media. Seeds of broccoli, tomato, and pepper were germinated in a 96-cell plug tray and grown to transplanting stage with the CWT system. A factorial experiment consisted of two growing media combined with CWT treatments of 2 and 4 cm. Excellent germination and high-quality seedlings were produced with all treatments. No differences were observed in growth of seedlings at 2 vs. 4 cm or between the two growing media. The CWT system is capable of maintaining a constant uniform water: air ratio in all plug cells on a commercial growing bench. Nutrient solution does not run off the bench. The CWT potentially is an excellent system for the irrigation of vegetable transplants.

Irrigation of Geraniums with an Automatic Controlled Water Table System

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 522d-522 ◽  
Author(s):  
J.W. Buxton ◽  
D.L. Ingram ◽  
Wenwei Jia
Keyword(s):  
Water Potential ◽  
Leaf Area ◽  
Water Table ◽  
Nutrient Solution ◽  
Irrigation System ◽  
Central Area ◽  
Dry Weight ◽  
Trickle Irrigation ◽  
Run Off ◽  
Optimum Water

Geraniums in 15-cm pots were irrigated automatically for 8 weeks with a Controlled Water Table (CWT) irrigation system. Plants were irrigated with a nutrient solution supplied by a capillary mat with one end of the mat suspended in a trough below the bottom of the pot. The nutrient solution remained at a constant level in the trough. Nutrient solution removed from the trough was immediately replaced from a larger reservoir. The vertical distance from the surface of the nutrient solution and the bottom of the pot determined the water/air ratio and water potential in the growing media. Treatments consisted of placing pots at 0, 2, 4, and 6 cm above the nutrient solution. Control plants were irrigated as needed with a trickle irrigation system. Geraniums grown at 0,2 and 4 CWT were ≈25% larger than the control plants and those grown at 6 CWT as measured by dry weight and leaf area. Roots of plants grown at 0 CWT were concentrated in the central area of the root ball; whereas roots of plants in other treatments were located more near the bottom of the pot. Advantages of the CWT system include: Plant controlled automatic irrigation; no run off; optimum water/air ratio.

scholarly journals A Study of Factors Influencing Plant Growth by WSN Approach and Plant Nutrient Deficiency Classification in Tomato Using SVM

2021 ◽  
Vol 23 (06) ◽  
pp. 36-46
Author(s):  
Vrunda Kusanur ◽  
◽  
Veena S Chakravarthi ◽  
Keyword(s):  
Machine Learning ◽  
Plant Growth ◽  
Nutrient Deficiency ◽  
Learning Model ◽  
Plant Nutrients ◽  
Polynomial Kernel ◽  
Second Phase ◽  
Nutrient Deficiencies ◽  
Deficiency Symptoms ◽  
Machine Learning Model

Soil temperature and humidity straight away influence plant growth and the availability of plant nutrients. In this work, we carried out experiments to identify the relationship between climatic parameters and plant nutrients. When the relative humidity was very high, deficiency symptoms were shown on plant leaves and fruits. But, recognizing and managing these plant nutrients manually would become difficult. However, no much research has been done in this field. The main objective of this research was to propose a machine learning model to manage nutrient deficiencies in the plant. There were two main phases in the proposed research. In the first phase, the humidity, temperature, and soil moisture in the greenhouse environment were collected using WSN and the influence of these parameters on the growth of plants was studied. During experimentation, it was investigated that the transpiration rate decreased significantly and the macronutrient contents in the plant leave decreased when the humidity was 95%. In the second phase, a machine learning model was developed to identify and classify nutrient deficiency symptoms in a tomato plant. A total of 880 images were collected from Bingo images to form a dataset. Among all these images, 80% (704 images) of the dataset were used to train the machine learning model and 20% (176 images) of the dataset were used for testing the model performance. In this study, we selected K-means Clustering for key points detection and SVM for classification and prediction of nutrient stress in the plant. SVM using linear kernel performed better with the accuracy rates of 89.77 % as compared to SVM using a polynomial kernel.

scholarly journals Production of Vegetable Transplants with the Controlled Water Table Irrigation System

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 633a-633
Author(s):  
Jack W. Buxton ◽  
Wenwei Jia
Keyword(s):  
Water Table ◽  
Nutrient Solution ◽  
Production Systems ◽  
Irrigation System ◽  
Root Penetration ◽  
Growing Medium ◽  
Cabbage Seed ◽  
The Media ◽  
Greenhouse Vegetable ◽  
Solution Surface

Cabbage seed was germinated and grown to transplanting size in a 98-cell tray using an automatic irrigation system based on the principle of maintaining a constant water table (CWT) relative to the growing medium in transplant trays. Seedlings obtained a nutrient solution from a capillary mat with one end suspended in a trough containing the solution. The distance between the nutrient solution surface and the transplant tray bottom was regulated with a water level controller. The nutrient solution was resupplied from a larger reservoir. A polyester material on top of the capillary mat allowed solution movement to the roots but prevented root penetration into the mat. The water table placement below the tray determined the water content in the growing medium. Seedling growth was evaluated using two growing media combined with two water table placements. Excellent quality seedlings were produced; the CWT irrigation system satisfactory provided water and nutrients for the duration of the crop. The only problems observed were dry cells, less than 2%, because of no media–mat contact and algae growth on the media surface using the higher water table. The CWT irrigation system is adaptable to existing greenhouse vegetable transplant production systems. It is automatic and can provide a constant optimum amount of moisture for seedling growing. It can be adjusted for phases of seedling growing such as more water during germination and can create water stress near transplanting time to either harden off or hold plants because of unfavorable planting conditions.

The Effects of Herbivory by a Mite, Aculus hyperici, and Nutrient Deficiency on Growth in Hypericum Species

1995 ◽  
Vol 43 (3) ◽  
pp. 305 ◽  
Author(s):  
AJ Willis ◽  
JE Ash ◽  
RH Groves
Keyword(s):  
Biological Control ◽  
Plant Growth ◽  
Hypericum Perforatum ◽  
Nutrient Deficiency ◽  
Combined Effects ◽  
Nutrient Deficiencies ◽  
Hypericum Perforatum L ◽  
Hypericum Species

The combined effects of herbivory by a mite, Aculus hyperici Liro, and a deficiency of nutrients on plant growth were measured for Hypericum perforatum L. and H. gramineum J.Forst. grown in a glasshouse. The results are discussed in relation to the biological control of H. perforatum, an introduced weed in southern Australia, relative to growth of its indigenous congener, H. gramineum. Growth of both species was reduced when infested with the mite, although the growth of H. perforatum was reduced by more than that of H. gramineum. Nutrient deficiencies also reduced growth of both species, especially of roots. Imposition of nutrient deficiency on mite-infested plants caused multiplicative reductions in plant growth equivalent to the product of the proportional reductions caused by either herbivory or nutrient deficiency alone.

scholarly journals 419 A Laboratory Demonstration of Water Stress on Plant Growth

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 465D-465
Author(s):  
J.W. Buxton ◽  
T.D. Phillips
Keyword(s):  
Water Stress ◽  
Plant Growth ◽  
Water Potential ◽  
Nutrient Solution ◽  
Irrigation System ◽  
Net Photosynthesis ◽  
Science Courses ◽  
Vertical Distance ◽  
Plant Water Potential ◽  
Solution Surface

Students in plant science courses have difficulty thoroughly understanding the effect of water stress on net photosynthesis and its consequences—reduced plant growth, productivity, quality, and profit. A laboratory demonstration utilizing a controlled water table irrigation system (CWT) provides a nearly constant plant water potential. Pots are placed on a capillary mat with one end suspended in a trough with nutrient solution. The vertical distance from the solution surface to the pot bottom determines the water potential; the water potential is 0 when the pot bottom is at the same level as the nutrient solution. The greater the vertical distance from solution to the pot bottom, the lower the water potential. For this demonstration, the bench was sloped from 0 to 10 cm above the solution over a distance of 90 cm. Corn, squash, soybean, fescue, and marigold seed were directly sown to either 9- or 15-cm pots and then placed on the CWT sloped bench at five vertical distances above the solution. Weekly, students observed plant growth and at the end of 8 weeks evaluated root and shoot growth. For all species, plant growth was indirectly related to the distance above the nutrient solution. Plants at near 0 water potential were much larger than those grown 8 to 10 cm above the solution.

scholarly journals Revisiting Sulphur—The Once Neglected Nutrient: It’s Roles in Plant Growth, Metabolism, Stress Tolerance and Crop Production

Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 626
Author(s):  
Tinashe Zenda ◽  
Songtao Liu ◽  
Anyi Dong ◽  
Huijun Duan
Keyword(s):  
Plant Growth ◽  
Abiotic Stresses ◽  
Crop Production ◽  
Production Systems ◽  
Crop Productivity ◽  
Plant Phenotyping ◽  
Special Importance ◽  
Nutrient Deficiencies ◽  
Sulphur Nutrition ◽  
Physiological Processes

Sulphur plays crucial roles in plant growth and development, with its functions ranging from being a structural constituent of macro-biomolecules to modulating several physiological processes and tolerance to abiotic stresses. In spite of these numerous sulphur roles being well acknowledged, agriculture has paid scant regard for sulphur nutrition, until only recently. Serious problems related to soil sulphur deficiencies have emerged and the intensification of food, fiber, and animal production is escalating to feed the ever-increasing human population. In the wake of huge demand for high quality cereal and vegetable diets, sulphur can play a key role in augmenting the production, productivity, and quality of crops. Additionally, in light of the emerging problems of soil fertility exhaustion and climate change-exacerbated environmental stresses, sulphur assumes special importance in crop production, particularly under intensively cropped areas. Here, citing several relevant examples, we highlight, in addition to its plant biological and metabolism functions, how sulphur can significantly enhance crop productivity and quality, as well as acclimation to abiotic stresses. By this appraisal, we also aim to stimulate readers interests in crop sulphur research by providing priorities for future pursuance, including bettering our understanding of the molecular processes and dynamics of sulphur availability and utilization in plants, dissecting the role of soil rhizospherical microbes in plant sulphur transformations, enhancing plant phenotyping and diagnosis for nutrient deficiencies, and matching site-specific crop sulphur demands with fertilizer amendments in order to reduce nutrient use inefficiencies in both crop and livestock production systems. This will facilitate the proper utilization of sulphur in crop production and eventually enhance sustainable and environmentally friend food production.

scholarly journals The Impact of Salt Stress on Plant Growth, Mineral Composition, and Antioxidant Activity in Tetragonia decumbens Mill.: An Underutilized Edible Halophyte in South Africa

Horticulturae ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 140
Author(s):  
Avela Sogoni ◽  
Muhali Jimoh ◽  
Learnmore Kambizi ◽  
Charles Laubscher
Keyword(s):  
Antioxidant Activity ◽  
Plant Growth ◽  
Mineral Composition ◽  
Nutrient Solution ◽  
Crop Production ◽  
Saline Water ◽  
Total Yield ◽  
Control Treatment ◽  
Antioxidant Power ◽  
The Impact

Climate change, expanding soil salinization, and the developing shortages of freshwater have negatively affected crop production around the world. Seawater and salinized lands represent potentially cultivable areas for edible salt-tolerant plants. In the present study, the effect of salinity stress on plant growth, mineral composition (macro-and micro-nutrients), and antioxidant activity in dune spinach (Tetragonia decumbens) were evaluated. The treatments consisted of three salt concentrations, 50, 100, and 200 mM, produced by adding NaCl to the nutrient solution. The control treatment had no NaCl but was sustained and irrigated by the nutrient solution. Results revealed a significant increase in total yield, branch production, and ferric reducing antioxidant power in plants irrigated with nutrient solution incorporated with 50 mM NaCl. Conversely, an increased level of salinity (200 mM) caused a decrease in chlorophyll content (SPAD), while the phenolic content, as well as nitrogen, phosphorus, and sodium, increased. The results of this study indicate that there is potential for brackish water cultivation of dune spinach for consumption, especially in provinces experiencing the adverse effect of drought and salinity, where seawater or underground saline water could be diluted and used as irrigation water in the production of this vegetable.

scholarly journals Optimizing hydroponic culture media and NO3−/NH4+ ratio for improving essential oil compositions of purple coneflower (Echinacea purpurea L.)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fatemeh Ahmadi ◽  
Abbas Samadi ◽  
Ebrahim Sepehr ◽  
Amir Rahimi ◽  
Sergey Shabala
Keyword(s):  
Particle Size ◽  
Essential Oil ◽  
Plant Growth ◽  
Plant Height ◽  
Growth Parameters ◽  
Echinacea Purpurea ◽  
Peat Moss ◽  
Root Weight ◽  
Total Biomass ◽  
Growing Media

AbstractMedicinal plants represent a valuable commodity due to beneficial effects of their natural products on human health, prompting a need for finding a way to optimize/increase their production. In this study, a novel growing media with various perlite particle size and its mixture with peat moss was tested for hydroponic-based production of Echinacea purpurea medicinal plant under greenhouse conditions. The plant growth parameters such as plant height, total fresh leave weight, fresh root weight, total biomass, total chlorophyll, leaf area, and essential oil compositions were assessed. Perlite particle size in the growing media was varied from very coarse (more than 2 mm) to very fine (less than 0.5 mm), and the ratio between perlite and peat moss varied from 50:50 v/v to 30:70 v/v. In addition, two nitrate (NO3−) to ammonium (NH4+) ratios (90:10 and 70:30) were tested for each growing media. The medium containing very fine-grade perlite and 50:50 v/v perlite to peat moss ratio was found to be most optimal and beneficial for E. purpurea performance, resulting in maximal plant height, fresh and dry weight, leaf surface area, and chlorophyll content. It was also found that an increase in NO3−/NH4+ ratio caused a significant increase in plant growth parameters and increase the plant essential oil content. The major terpene hydrocarbons found in extract of E. purpurea with the best growth parameters were germacrene D (51%), myrcene (15%), α-pinene (12%), β-caryophyllene (11%), and 1-Pentadecene (4.4%), respectively. The percentages of these terpene hydrocarbons were increased by increasing of NO3−/NH4+ ratio. It can be concluded that decreasing the perlite particle size and increasing the NO3−/NH4+ ratio increased the plant growth parameters and essential oil compositions in E. purpurea.

Effects of Nitric Oxide Application on Antioxidant Enzyme Activities of Pepper Plants under Drought Stress

2021 ◽  
Vol 5 (4) ◽  
pp. 846-853
Author(s):  
Fikret YAŞAR ◽  
Özlem ÜZAL
Keyword(s):  
Nitric Oxide ◽  
Drought Stress ◽  
Plant Growth ◽  
Nutrient Solution ◽  
Enzyme Activities ◽  
Growth Parameters ◽  
Antioxidative Enzyme ◽  
High Dose ◽  
Antioxidant Enzyme Activities ◽  
Hoagland Nutrient Solution

The purpose of the study was to determine the relationship between the messenger molecule Nitric oxide (NO) and antioxidative enzyme (SOD: Superoxide Dismutase; CAT: Catalase; APX: Ascorbate Peroxidase) activities in some metabolic changes that occur under the effect of drought stress in plants, to determine the possible roles of Nitric Oxide and to obtain complementary information. The experiment conducted in a controlled environment, and plant were cultured in containers containing Hoagland nutrient solution. For drought stress application, 10% Polyethylene Glycol (PEG 6000) was added to the nutrient solution, which is equivalent to -0.40 MPa osmotic potential. Before the drought stress is applied, pepper seedlings of Demre cv were pre-treated with different doses of Sodium Nitroprusside (SNP) and Carboxy-PTIO (potassium salt) (cPTIO) (SNP 0.01, SNP 1, SNP 100 and SNP 0.01 + cPTIO, SNP + cPTIO, SNP 100+ cPTIO). On the 10th day of the drought application, the growth parameters of the plants; the plant fresh weights and their Antioxidative Enzyme Activities (SOD, CAT, APX) were determined. In terms of plant growth parameters, both plant growth and antioxidant anzyme activities of plants pretreated with 0.01 and 1 doses of SNP were lower than the high dose of SNP and the PEG application without pretreatment. The reason for the low enzyme activities in these applications can be attributed to factors such as the excess accumulation of organic acids such as proline in the cells of the plants and the decrease in H2O2 and O-2 levels in the presence of SNP.

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