Low Nutrient Solution Research Articles

Yield and oil content of castor oil plant (Ricinus communis L.) accessions grown with fertigation in a semiarid zone

Objective: To evaluate seed, dry matter, and oil content yield in five accessions of castor oil plant (Ricinus communis L.) in the Altiplano Potosino Zacatecano high plateau region of Mexico, grown with a fertigation system on a mixture of sand, tezontle, and compost, with three fertilization levels.Design/Methodology/Approach: The following accessions showed an outstandingly favorable response to fertilization: ZACS2C1 (Orito Zac) which had the greater seed yield (735 g) and oil content (50.30 ± 5.23); and SLPS11C1 which had the greater weight per100 seeds (56.77 ±2.35) and dry matter (1600 g).Results: The best fertilization level for the abovementioned accessions was obtained with the low nutrient solution,Limitations/Implications of the study: while other accessions showed a variable and inverse response to the fertilization level. Results/Conclusions: To make the most of the castor oil plant, oil or fodder accessions can be selected or both accessions can be sown under an intercropping system.

Enlarging of Grape Hyacinth Bulb at Different Nutrient Solution Ratios in Soilless Culture

ABSTRACT Grape hyacinth bulbs must be of a certain size in order to bloom. It is commercially important to extend the circumference of grape hyacinth bulbs in a short time. This study was conducted to determine the effects of different nutrient solution rates on the bulb enlargement, the bulblet formation and plant growth characteristics in soilless culture. Grape hyacinth bulbs (Muscari armeniacum Leichtlin ex Baker) with a circumference of 3 cm were grown in perlite bag culture at six different nutrient solution rates (25%, 50%, 75%, 100%, 125% and 150% of the final nutrient solution). According to the variance analysis; the effect of nutrient solution ratios on bulb diameter, bulb weight, bulblet number, adventitious root number, adventitious root length, adventitious root weight, leaf length and leaf weight was found to be insignificant. Bulb diameter enlarged between 14.44% and 29.13%. Bulb diameter varied between 10.95 mm and 12.20 mm, bulb weight 0.74–0.90 g, bulblet number 1.00–1.56 piece, leaf length 23.05–27.33 cm. Electrical conductivity (EC) of drainage waters increased with increasing nutrient solution ratio. A positive correlation was determined between leaf number and bulb diameter, nutrient solution ratio and EC. In addition, a positive correlation was determined between bulb weight, leaf number and EC and bulblet number. All these results showed that grape hyacinth bulbs could maintain their normal development at low nutrient solution doses, thus saving on fertilizers.

Recent advances on regiocentric homo-epitaxial approaches in bio-mimetically derived artificial non-wettable surfaces

Abstract Natural biosurfaces shows water repellence mainly because of its unique surface roughness and peculiar chemical compositions. Herein, we have mimicked the properties of the natural, non-wettable surfaces and created artificial water repellent surfaces using perpendicularly aligned zinc oxide (ZnO) nanostructured coatings having rough surface texture. These non-wettable surfaces were prepared through simple seed assisted hydrothermal methods. In the present method, a seed layer of nano regime zinc oxide was initially prepared on clean glass slides by coating and calcination methods. The as-synthesized seed layer was utilized for the hydrothermal growth of vertically oriented nanostructures. The structural and functional features of the resultant samples were studied using XRD, FTIR, UV-Vis. spectrophotometer and Contact angle analyzer. The homo-epitaxial growth and the crystallinity of ZnO nano particles were assessed using XRD. The structural studies were performed using FTIR and the optical transparency studies of the samples were carried out using UV–Vis. spectrophotometer. Along with the photographic image analyses, the water contact angle analyses were performed to predict the non-wettable character of the resultant coatings. At low nutrient solution concentrations (10 mM) and at low seed solution concentrations (1–10 mM), hydrophobic nanomaterials surfaces with high water contact angle, ˃130°, were successfully prepared through the present hydrothermal methods that extends many practical applications in biomedical, defense and industrial sectors.

Bottom-cold stress was less harmful than cold-air stress on tomato seedling production treated with boric acid

Boron is beneficial element can help plants face chilling stress. This research was arranged using factorial experiment based on randomized complete block design on Lycopersicon esculentum var. Infinity in Isfahan University of Technology due to having a new idea about bottom-cold and cold-air stress tomato seedling with boron application. There were two treatments having different boron (B1) concentrations (B1) 50.5 mM, and (B2) 75.82 mM. Three temperature treatment used as following: (1) the cold treatment used with vegetation chambers with low temperature (10 °C) (cold air), (2) the low nutrient solution (10 °C) temperature but the aerial part exposed to optimum temperature (bottom-cold) and (3) the last part, was the control plant (opt) keep in optimum root and shoot temperature (22 °C). Some physiological and biochemical characteristics were measured. The results were shown that boron uptake decreased in cold or stress as well as the water status of the plant which is suffering from cold-air stress greater than bottom-cold. Boron application, especially in higher concentration, improved some deleterious effect of cold stress, especially in the bottom-cold. The reason may refer to keeping photosynthesis traits in better level with B application. Cold-air stress, increased stress indices such as antioxidant and proline as well as glucose level and saturated/unsaturated fatty acid greater than bottom-cold stress. It was concluded that tomato was more resistant to bottom-cold stress than cold-air stress. Boron application increased the boron of leaves more effectively in the bottom-cold consequently increase plant tolerance to a chilling condition at the bottom-cold too.

Time-course of Growth and Main Bioactive Compound Concentrations in Red Perilla under Low Nutrient Solution Temperature Treatment

Time-course of Growth and Main Bioactive Compound Concentrations in Red Perilla under Low Nutrient Solution Temperature Treatment

A Low Nutrient Solution Temperature and the Application of Stress Treatments Increase Potato Mini-tubers Production in an Aeroponic System

This study was conducted to test the impact of the nutrient solution temperature and the application of different stress treatments at tuberization on several growth variables for two potato cultivars grown in an aeroponic system. At 25 days after transplanting, low pH level, wilting stress and nitrogen withdrawal under warm (24 °C) and cool (18 °C) root-zone temperatures were applied to potato plants cv. Mystere and Chieftain. Significant differences in mini-tuber production, stolon number and length and root length were observed among root zone temperatures, stress treatments and cultivars. Cooling the nutrient solution temperature to 18 °C significantly increased most growth variables and tuber yield for both cultivars. Plants subjected to nitrogen withdrawal at tuberization out-performed plants of the other treatments as well as the control and exhibited faster tuberization, higher mini-tuber number and weight as well as significantly higher root length, stolon number/plant and number of stolon branches/plant. The low pH and wilting treatments reduced plant growth and mini-tuber number/plant. They dramatically increased the number of stolon branches/plant and stolon number respectively. However, this increase did not counteract the negative effects on the other variables. The results of this study demonstrate that a judicious use of these stresses can effectively promote tuberization in aeroponics.

Improved Nutrient Uptake Enhances Cotton Growth and Salinity Tolerance in Saline Media

Two experiments were conducted to determine if improved nutrient uptake increases salinity tolerance of cotton (Gossypium hirsutum L.). A transgenic cotton line (CMO3) with increased salt tolerance and its wild line (SM3) were grown in pots containing substrate (peat:vermiculite = 1:1, v/v) in the first experiment, while cotton (‘SCRC 28’) was cultured in hydroponics with a split-root system in the second experiment. Contents of essential nutrient elements and Na+ in plant tissues, leaf photosynthesis (Pn) and chlorophyll (Chl) concentration and plant biomass were determined after salinity [sodium chloride (NaCl)] treatment in both experiments. In the first experiment, salinity stress with 150 mM NaCl reduced plant biomass and photosynthesis (Pn) of both SM3 and CMO3 compared with their non-stressed controls, but the CMO3 suffered significantly lower reductions than SM3, suggesting an increased salinity tolerance of CMO3 relative to SM3. Total uptake and contents of main nutrient elements [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn)] in CMO3 were higher than those in SM3. Also, less sodium (Na+) accumulation and lower extreme ratios of Na/N, Na/P, Na/K, Na/Ca, Na/Mg, Na/Fe, Na/Mn, Na/Cu, and Na/Zn were observed in CMO3 than in SM3. Increased salt tolerance in transgenic AhCMO cotton was probably attributed to its superior nutrient uptake compared with SM3. In the second experiment, the non-stressed root half fed with moderate level of nutrient solution and salt-stressed half fed with low level of nutrient solution (CMN/SLN) exhibited higher salinity tolerance than salt-stressed root half fed with moderate level of nutrient solution and non-stressed root half fed with low nutrient solution (CLN/SMN). Plants absorbed more nutrients but less Na+ under CMN/SLN than CLN/SMN. The overall results suggest that improved nutrient uptake played an important role in the enhanced salt tolerance of cotton.

The Influence of Drip Irrigation or Subirrigation on Zucchini Squash Grown in Closed-loop Substrate Culture with High and Low Nutrient Solution Concentrations

Zucchini plants (Cucurbita pepo L. cultivar Afrodite) were grown during a summer–fall season in closed-soilless systems using a mixture peat–pumice to evaluate the effects of irrigation system (drip irrigation and subirrigation) and nutrient solution concentration (half = 1 dS·m−1 and full = 2 dS·m−1) in terms of substrate electrical conductivity (ECs) using the dilution 1:1.5 media:water method, growth, yield, leaf mineral composition, fruit quality, and mineral solution composition. At the end of the cultural cycle, the highest ECs at the upper (0 to 7.5 cm) and lower (7.5 to 15.0 cm) layers were recorded with subirrigation using a full nutrient solution concentration. The highest plant growth, yield, and leaf macroelements concentration (nitrogen, phosphorus, and potassium) were recorded in both irrigation systems using a full-strength solution, followed by drip irrigation, and finally by subirrigation treatment using a half-strength nutrient solution. Fruit yield, fruit mineral composition (phosphorus, potassium, calcium, and magnesium), and leaf macroelements concentration (nitrogen, phosphorus, potassium, and magnesium) were substantially reduced when the concentrations of macronutrients in the feed solution were lowered to 50% of control. Using half-nutrient solution concentration, the marketable yield reduction was more pronounced with subirrigation (58%) than with drip irrigation (42%). The variation of the macronutrient and EC in the solution during the growing cycle was less pronounced in the subirrigation than with the drip irrigation system, which represents an important aspect for the simplification of the closed-loop management of the nutrient solution.

EFFECT OF DIFFERENT PREHARVEST CONDITIONS ON THE POSTHARVEST KEEPING QUALITY OF GREENHOUSE TOMATOES

ISHS International Workshop on Models for Plant Growth and Control of Product Quality in Horticultural Production EFFECT OF DIFFERENT PREHARVEST CONDITIONS ON THE POSTHARVEST KEEPING QUALITY OF GREENHOUSE TOMATOES

Interactions between ammonium and pH of the nutrient solution supplied to gerbera ( Gerbera jamesonii ) grown in pumice

The interactions between the NH4-N/total-N supply ratio (Nr) and the pH of the nutrient solution delivered to the plants regarding the nutrient availability and its influence on plant growth and yield were investigated in a gerbera crop grown in pumice. Four treatments obtained by combining a low and a high Nr (0.02 and 0.13 on a molar basis, respectively) with two different levels of nutrient solution pH (5.0 and 5.8, respectively) were compared in a long-term glasshouse experiment. The low Nr resulted in significantly higher pH levels in the rhizosphere, as indicated by the values measured in the drainage water. A high nutrient solution pH further increased pH in the root zone at low Nr but had no influence on it at the higher Nr level. The high pH in the root zone restricted significantly the Cu, Mn, and Zn uptake as indicated by both analytical results and visual symptoms, which were typical for Cu- and Mn-deficiencies. Mn-deficiency was induced only when a low Nr was combined with a high nutrient solution pH. The Cu-deficiency symptoms appeared earlier, were more severe and occurred also when the low Nr was combined with a low nutrient solution pH, but to a lesser extent. As a result of these nutrient deficiencies, both the growth and the flower yield were severely restricted when Nr was low. These results indicate that gerbera is prone to Cu- and Mn deficiencies at pH values above 6 in the rhizosphere. The maintenance of root zone pH below this level in soilless culture is most successfully attained by properly adjusting the NH4-N/total-N supply ratio rather than the pH of the nutrient solution delivered to the plants.

Model-based Control of Nutrient Solution Concentration Influences Tomato Growth and Fruit Quality

Diurnal changes in microclimate in a greenhouse are often greater than changes in daily averages over weeks or months. Thus, one may hypothesize that changing the nutrient solution concentration supplied to plants at intervals less than one day would improve tomato yield and quality. To test this hypothesis research was conducted to compare four nutrient control strategies for their effects on plant growth, fruit yield, fruit quality, and root characteristics of `Counter' tomato [Lycopersicon esculentum (L.) Mill.]. The four strategies were 1) ECvariable, adjustment of nutrient solution electrical conductivity (EC) at 15-min intervals according to greenhouse microclimate over the previous 15-min and empirical models of photosynthesis and transpiration; 2) ECdaily, daily adjustment of nutrient solution EC based on each morning's 24-hour weather forecast; 3) EC3.7, supply of a single high nutrient solution of 3.7 dS·m-1; or 4) EC1.5, low nutrient solution EC of 1.5 dS·m-1 for the entire growth period. Mean effluent EC levels were 1.8 dS·m-1 for treatment EC1.5, 5.1 dS·m-1 for treatment EC3.7, 3.6 dS·m-1 for treatment ECdaily, and 3.4 dS·m-1 for treatment ECvariable. Except for fresh weight (FW) of roots, growth characteristics did not differ significantly among treatments. Total production averaged 12.2 kg·m-2 FW and 1.0 kg·m-2 dry weight (DW); and fruit yield averaged 6.7 kg·m-2. Dry matter content, yield loss to blossom-end rot, and firmness responded linearly to treatment EC. In general, ECdaily yielded higher fruit quality and ECvariable lower fruit quality than that predicted by linear regression. Although our strategy of short-term dynamic changes of nutrient solution EC according to changes in climate variables did not increase yield, daily adjustment of nutrient solution EC improved external fruit quality characteristics and may be practical for grower adoption.

PHOTOSYNTHESIS, WATER RELATIONS AND GROWTH RESPONSES OF GREENHOUSE TOMATO PLANTS TO HIGH-SOLUTION ELECTRIC CONDUCTIVITY AND LOW SOIL WATER CONTENT: SOIL WATER DEFICIT ACCLIMATION AND SALT BUILD-UP EFFECT

Greenhouse tomato plants (cv. Capello) were grown in peat moss based substrate and treated with high and low nutrient solution electric conductivity (EC) under high (95±5%) and low (55±8%) soil water conditions. Photosynthesis (Pn) was decreased about 25% 1 day after soil water content reached 55%. However, as the soil water deficit was prolonged, the effect of water deficit diminished, with the decreasing extent of ca 15% on the 11th and 16th days from starting treatments. This suggested that tomato plants acclimated to soil water deficit. One day after soil water content reached 55%, leaf turgor potential (TP) decreased largely as leaf water potential (WP) dropped. However, as soil water level was kept constant for a period, TP recovered to a quite large extent even at the same WP level. This TP recovery accounted for the photosynthetic recovery. Drying the constantly well watered plants to the same soil water level decreased Pn to a much larger extent than did the prolonged soil water deficit. This supports the above-mentioned photosynthetic acclimation. The effects of high EC were not observed 1 day after the treatments started, but became larger and larger as the treatments were prolonged. Build-up of EC in the soil accounted for this result

Effect of Concentration of Nutrient Solution on Vegetative Growth and Fruit Yield of Hydroponically Grown Tomato Plants.

Tomato (Lycopersicon esculentum Mill. ev. Ogatazuiko) plants were grown in low concentration (a quarter of the control levels) or control (full strength Yamasaki's tomato solution until 7 weeks, and then 1.5 fold strength) . The EC of the low nutrient solution was adjusted daily to avoid deficiency of nutrient supply. There was significant reduction in leaf dry weight, stem dry weight, crop growth rate (CGR) and leaf area index (LAI) of plants grown in low nutrient solution after 6 weeks. These differences were present for the next 9 weeks. There were no significant differences in root dry weight, total number of fruits and early fruit yield, but the total fruit yield from plants grown in low nutrient solution was 32% less than that from the control plants. The relative amount of assimilate in the fruit and the net assimilation rate (NAR) of plants grown in low nutrient solution was significantly greater than the control plants from week 6 to week 12, however, it was less than the control plants at week 15. The concentration of nutrient solution had no effect on the P, Ca and Mg content in leaves, but the N and K content in leaves was significantly lower in plants grown in low nutrient solution than in control plants at week 15. The experiment showed that it is possible to control excessive vegetative growth without the loss of fruit yield by the use of a low concentration of nutrient solution (EC 0.7-0.9 dS/m) with the frequent supplementing of N and K after topping.

Evaluation of nutrient solution phosphorus concentration on potato plantlet tuber production under greenhouse conditions1

Abstract Phosphorus fertilizer management of greenhouse grown micropropagated potato plantlets has been based on field research. Differences in growing conditions, potting media and the planting material itself may make the field research data base unacceptable in a greenhouse environment. This study was conducted to determine the optimum nutrient solution phosphorus (P) concentration for maximum growth and yield of micropropagated potato plantlets grown under greenhouse conditions. Nutrient solution P concentrations ranging from 0 to 55 μg P/ml were evaluated. Each nutrient solution P concentration was applied weekly to micropropagated potato plantlets that were grown in 80% vermiculite‐20% sand potting medium. Results indicate that P concentrations between 10 and 35 μg P/ml are optimum for potato plantlet tuber production. This P concentration range maximizes vegetative weight, total tuber weight and number of tubers produced per micropropagated potato plantlet. Data further indicated that the potting medium retained and possibly accumulated P from the weekly applied nutrient solution. This enabled the plants, receiving relatively low nutrient solution P concentrations, to extract more P for proper growth and yield with time. To avoid unnecessary nutrient costs, the 15 μg P/ml nutrient solution concentration is recommended. This P concentration will produce maximum tuber yields and still allow for less than optimum management which may cause P conversion to unavailable forms. Additional studies should be conducted to correlate plant tissue concentration at different growth stages with final tuber yields.

Aluminum effects on micronutrient uptake by annual ryegrass

Abstract Four ryegrass (Lolium multiflorumLam.) cultivars were grown in 1/5 Steinberg nutrient solution supplemented with six Al levels (0, 37, 74, 148, 296, or 592 umol L‐1) at pH initially adjusted to 4.2. Average net Fe influx was stimulated at low nutrient solution Al levels. This stimulation was larger for more Al‐tolerant cultivars Marshall and Gulf. Decreases in average net Mn and Zn influxes were brought about by increasing Al levels in the nutrient solution. The average net influx of Fe, Mn, and Zn was positively correlated with the root tolerance index (relative root yield of plants grown with and without Al added to the nutrient solution). For more Al‐tolerant cultivars, increased total uptake of Fe and Cu was brought about by increased nutrient solution Al levels up to 74 umol L‐1. Decreases in total uptake of Mn and Zn were generally noted with increased nutrient solution Al levels. Percentage inhibition of total Fe, Mn, Zn, and Cu uptake was negatively correlated with the mean pH of the Al‐containing nutrient solutions. The higher average net influx and the smaller percentage inhibition of total Fe uptake at nutrient solution Al levels up to 74 umol L‐1can be used as indicators in ranking ryegrass cultivars as more Al‐tolerant