Half-strength Hoagland's Solution Research Articles

Nutrient management effects on sweetpotato genotypes under controlled environment.

Sweetpotato is one of several crops recommended by National Aeronautics and Space Administration (NASA) for bioregenerative life support studies. One of the objectives of the Tuskegee University NASA Center is to optimize growth conditions for adaptability of sweetpotatoes for closed bioregenerative systems. The role of nutrient solution management as it impacts yield has been one of the major thrusts in these studies. Nutrient solution management protocol currently used consists of a modified half Hoagland solution that is changed at 14-day intervals. Reservoirs are refilled with deionized water if the volume of the nutrient solution was reduced to 8 liters or less before the time of solution change. There is the need to recycle and replenish nutrient solution during crop growth, rather than discard at 14 day intervals as previously done, in order to reduce waste. Experiments were conducted in an environmental growth room to examine the effects of container size on the growth of several sweetpotato genotypes grown under a nutrient replenishment protocol. Plants were grown from vine cuttings of 15cm length and were planted in 0.15 x 0.15 x 1.2m growth channels using a closed nutrient film technique system. Nutrient was supplied in a modified half strength Hoagland's solution with a 1:2.4 N:K ratio. Nutrient replenishment protocol consisted of daily water replenishment to a constant volume of 30.4 liters in the small containers and 273.6 liters in the large container. Nutrients were replenished as needed when the EC of the nutrient solution fell below 1200 mhos/cm. The experimental design used was a split-plot with the main plot being container size and genotypes as the subplot. Nine sweetpotato genotypes were evaluated. Results showed no effect of nutrient solution container size on storage root yield, foliage fresh and dry mass, leaf area or vine length. However, plants grown using the large nutrient solution container accumulated more storage root dry mass than those with the small containers. Although plants grown with the smaller containers showed greater water uptake, plant nutrient uptake was lower than with the larger container. All genotypes evaluated showed variation in their responses to all parameters measured.

Effect of EDTA and low calcium fertility on pericarp cation levels and ripening of rin tomato fruit

Ripening inhibited ( rin ) tomato plants were grown in silicate sand and watered with half-strength Hoagland's solution until flowering. After flowering, plants were watered until run-off daily with full-strength Hoagland's solution containing 5 mM (control) or 1 mM calcium, or full-strength Hoagland's solution with 1.25 mM or 2.5 mM Na 2 EDTA. Fruit pericarp calcium levels were the same in Na 2 EDTA and control treatments at 90 days postpollination. The 1 mM Ca treatment significantly decreased total pericarp Ca levels compared to the control treatment. Sodium levels were higher in fruit from Na 2 EDTA-treated plants than controls. Fruit from control and 1 mM Ca treatments had significantly higher Zn than fruit from the Na 2 EDTA-treatments. None of the treatments induced increased ethylene production, redness, or increased soluble solids content of rin fruit.

RESPONSES OF SEVERAL SWEETPOTATO GENOTYPES TO SOLUTION REPLENISHMENT IN HYDROPONIC CULTURE

A study was initiated in an environmental growth room to examine the effects of container size on the growth of several sweetpotato genotypes grown under a nutrient replenishment protocol. Plants were grown from vine cuttings of 15 cm in length, planted in 0.15 × 0.15 × 1.2-m growth channels using a closed nutrient film technique system. Nutrient was supplied in a modified half-strength Hoagland's solution with a 1 N: 2.4 K ratio. Nutrient replenishment protocol consisted of daily water replenishment to a constant volume of 38.4 liters in the small reservoir and 345.6 liters in the large reservoir. Nutrients were replenished as needed when the EC of the nutrient solution fell below 1200 mhos/cm. The design used was a split-plot with the main plot being container size and genotypes the subplot. Nine genotypes were evaluated: J6/62, J6176, J8/1, PX/6, PX/10, PX/36, TU-82-155, TU-J1, NCC58. Results showed no effect of container size on storage root yield, foliage fresh and dry mass, leaf area, or vine length. However, plants grown in the large container accumulated more storage root dry mass than those in the small container. All genotypes evaluated showed variation in their responses for all parameters measured.

Morpho-physiological Responses of Pinus halepensis Mill. Seedlings to Drought Stress

Aleppo Pine (Pinus halepensis Mill.) is known to be the most drought-resistant Mediterranean Pine. This species is widely distributed throughout the Mediterranean region and displays a high intraspecific variability, with respect to its physiological and morphological response to environmental conditions. In this experiment we evaluated the response of Pinus halepensis seedlings to drought. Sixty germinated seeds (accession A6, Shaharia, Israel) were grown in soil for 8 weeks and then transferred to black plexiglass tanks containing half-strength air-sparged Hoagland solution. After 6 weeks of acclimation to hydroponics, the osmotic potential of the solution was lowered by adding polyethylene-glycol (PEG) 8000. Water potential was lowered in 0.2 MPa increments every 4 days, until a final value of –0.8 was reached. The seedlings were then maintained at –0.8 MPa for a further 8 days. Ultrasonic acoustic emissions, pressure–volume (P–V) curves, shoot and root growth, leaf area, xylem diameter, root apex mitotic index and cell length were measured on control and stressed seedlings. Seedlings were then transferred to normal Hoagland solution for 24 hours to simulate rewatering, and P–V curves and ultrasonic emissions measurements were repeated. Results showed that the final root growth is maintained in the stressed seedlings at the same rate as controls, whereas shoot growth was significantly reduced. The leaf area was reduced by stress to 36%, but the xylem diameter only to 10%, leading to a lower leaf area:xylem section ratio in the stressed plants. Ultrasonic emissions in the stressed plants were 365% of the control, and 182%, after rewatering. Specific details of the growth and physiology data are presented.

Growth Responses of Hydroponically Grown Sweetpotato Tolerant and Intolerant of a Continuous Daily Light Period

Two sweetpotato [Ipomoea batatas (L.) Lam] genotypes (`Georgia Jet' and the breeding clone TI-155) were grown at 12-, 15-, 18-, and 21-h light/12-, 9-, 6-, 3-h dark cycles, respectively, to evaluate their growth and elemental concentration responses to duration and amount of daily lighting. Vine cuttings (15 cm long) of both genotypes were grown in rectangular nutrient film technique channels for 120 days. Conditions were as follows: photosynthetic photon flux (PPF) mean 427 μmol·m–2·s–1, 28C day/22C night air cycle, and 70% ± 5% relative humidity. The nutrient solution used was a modified half-strength Hoagland's solution. Storage root count per plant and per unit area, yield (in grams per square meters per day), and harvest index increased, while production efficiency (in grams per mole) decreased with increased daily PPF. Stomatal conductance for both genotypes declined with increased daily PPF. Leaves were smallest for both genotypes at the 21-h light period, while storage root yield declined as leaf area index increased. Except for a linear decrease in leaf N and K with increased light period, elemental concentration was not significantly influenced.

Foliage Removal Influences Sweetpotato Biomass Yields in Hydroponic Culture

Greenhouse studies were conducted to determine the effect of harvesting sweetpotato [Ipomoea batatas L. (Lam.)] foliage tips (terminal 15 cm) on storage root yield, edible biomass index (EBI), and linear growth rate. Plants were grown hydroponically from 15-cm vine cuttings planted in 0.15 × 0.15 × 1.2-m growth channels using a recirculating nutrient film technique system. Nutrients were supplied from a modified half-strength Hoagland solution with a 1 N: 2.4 K ratio. Foliage tips were removed at 14-day intervals beginning 42 days after transplanting. Final harvest was at 120 days after planting. At the end of the growing season, harvested foliage tips totaled 225 g/plant (fresh mass). Foliage removal significantly reduced storage root yield, shoot biomass, and linear growth rate expressed on a canopy cover basis. The EBI was higher for plants with foliage removed than for the control.

Selenium Affects Sulfur Uptake and Metabolism in Onions (Allium cepa L.)

The affects of selenium (Se) on sulfur (S) uptake and metabolism were evaluated in `Granex 33' onions. Plants were grown in a half-strength Hoagland's solution and modified with increasing Se fertility. Selenium was added as sodium selenate. During growth, plants were sampled biweekly and divided into root, bulb, and foliar tissue. Tissues were dried and ground for total S, and wet-ashed for total Se (GFAA). Selenium increased S uptake by onions. As Se increased in concentration, S utilization first increased then decreased in a quadratic trend.

Effects of Various Nitrate: Ammonium Ratios on Sweetpotato Growth

A study was initiated in the greenhouse to examine the effects of five \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}:\mathrm{NO}_{3}^{-}\) \end{document} ratios on sweetpotato growth. Plants were grown from vine cuttings of 15-cm length, planted in 0.15 x 0.15 x 1.2-m growth channels using a closed nutrient film technique system. Nutrient was supplied in a modified half-strength Hoagland's solution with a 1:2:4 N:K ratio. \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}:\mathrm{NO}_{3}^{-}\) \end{document} ratios investigated were 100:0, 0:100, 40:60, 60:40, and a control that consisted of a modified half-Hoagland solution with an N:K ratio of 1:2:4 and an \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}:\mathrm{NO}_{3}^{-}\) \end{document} of 1:7. Treatments were initiated 30 days after planting (DAP). Sequential plant harvest began 30 DAP and continued at 30-day intervals until final harvest at 150 DAP. Results showed a linear increase in fresh storage root fresh weight until 90 DAP for all treatments. However, from 60 DAP until the end of the growing season, plants grown in a 100% \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document} solution consistently produced significantly less storage roots than in all other treatments. While all other treatments showed a decrease in storage root fresh weight after 90 DAP, plants grown in 100% \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NO}_{3}^{-}\) \end{document} and the control solution continued to increase linearly in storage root production. Storage root dry weight throughout the growing season followed similar trends to that of storage root fresh weight. Data suggest that a nutrient solution containing NO–3as its sole nitrogen source may be adequate for sweetpotato growth. This would make it possible for utilizing a one-way pH control method for nutrient solution.

Variation in Salinity Tolerance in Sunflower (Helianthus annum L.)

AbstractForty‐five accessions of sunflower collected from different countries were screened for salinity tolerance after 2 weeks growth in sand culture salinized with 150 meq l−1 of NaCl2+ CaCl2 (1:1 ratio equivalent wt. basis) in half strength Hoagland's nutrient solution. The results for plant biomass of 45 accessions show that there was considerable variation in salinity tolerance.In a further greenhouse experiment, the salinity tolerance of three tolerant (HO‐1, Predovik, Euroflor) and two sensitive (SMH‐24, 9UO‐985) lines (selected on the basis of their performance in the seedling experiment) was assessed at the adult stage to evaluate the consistency of salinity tolerance at different growth stages. All three salt tolerant accessions produced significantly greater plant biomass, seed yield and seed oil content than the salt sensitive accessions. The tolerant accessions accumulated less Cl− and more K+ in the leaves under saline conditions compared with the salt sensitive accessions. The salt tolerant accessions also maintained relatively high leaf K:Na ratio and K+ versus Na+ selectivity. Although statistically nonsignificant, all three tolerant accessions had greater soluble carbohydrates, soluble proteins, total free amino acids and proline in the leaves than the sensitive accessions. A field trial conducted in a salt‐affected field confirmed the greenhouse results of the selected accessions.This study shows that salinity tolerance of sunflower does not vary with stage of plant cycle, so selection for increased salt tolerance can be carried out at the initial growth stage. Secondly, it is found that there is great variation of salt tolerance in sunflower. Low uptake of Cl−, high uptake of K+, and maintenance of high K:Na ratios and K+ versus Na+ selectivity in the leaves and possibly the accumulation of organic osmotica such as soluble carbohydrates, soluble proteins, proline and free amino acids seem to be the important components of salt tolerance in sunflower.

Nutrient accumulation and distribution of wheat genotypes in response to waterlogging and nutrient supply

The effect of soil waterlogging and nutrient supply on plant nutrient accumulation and distribution was investigated for two genotypes of winter wheat (Triticum aestivum L.) differing in waterlogging resistance, ‘Bayles’ and ‘Savannah’. Plants were grown in waterlogged or drained sand and fertilized with half-strength or full-strength Hoagland's solution. Waterlogging reduced the concentrations of N, P, K, Mg, and Zn in leaves and stems and increased the concentrations of those elements in the root system. The effects were greater for waterlogging-sensitive Bayles than for waterlogging-resistant Savannah. Higher concentrations of Fe and Mn were found in waterlogged plants compared to the control plants for sensitive Bayles. Waterlogging increased the proportion of N and Zn in the root system and decreased that of K in stems for Bayles. The proportion of Fe increased in leaves and stems for Bayles and Savannah under waterlogged conditions, but to a greater extent for Bayles. Doubling the concentrations of all major and minor nutrient elements supplied to the waterlogged rooting medium improved plant nutrient status and enhanced plant dry matter production.

Leaf Phosphate Status, Photosynthesis, and Carbon Partitioning in Sugar Beet (IV. Changes with Time Following Increased Supply of Phosphate to Low-Phosphate Plants).

Changes in photosynthesis, carbon partitioning, and growth following resupply of orthophosphate (Pi) to moderately P-deficient plants (low-P) were determined for sugar beets (Beta vulgaris L. cv F58-554H1) cultured hydroponically in growth chambers. One set of plants was supplied with 1.0 mM Pi in half-strength Hoagland solution (control plants), and a second set (low-P plants) was supplied with 0.05 mM Pi. At the end of 2 weeks, the low-P plants were resupplied with 1.0 mM Pi. Low-P plants rapidly accumulated large amounts of Pi, and the photosynthesis rate increased to control values within 4 to 6 h. The rate of photosynthesis appeared to be controlled by ribulose-1,5-bisphosphate (RuBP); low P reduced photosynthesis and RuBP levels, and P resupply increased photosynthesis and RuBP in a manner parallel with time. Low-P treatment reduced adenylate levels substantially but not nicotinamide nucleotides; adenylate levels recovered to control values over 3 to 6 h. With low P, more photosynthate is allocated to non-P carbon compounds (e.g. starch, sucrose) than to sugar phosphates. When P is resupplied, sugar phosphates increase as starch and sucrose pools decrease; this increase in leaf (chloroplast) sugar phosphates was most likely responsible for the increases in RuBP and photosynthesis and may have increased adenylate levels (through enhanced levels of ribose-5-phosphate).

GROWTH ANALYSIS OF A SWEETPOTATO CULTIVAR GROWN IN AN NFT SYSTEM

One of the major objective of growth analysis data is to provide a basic understanding of some of the mechanisms that affect plant growth. This study was initiated to evaluate the effects on several growth parameters when plants are grown in an NFT system. Vine cuttings (15 cm length) of the sweetpotato cultivar ``Georgia Jet” was grown in a closed NFT system for a period of 120 days. Nutrient was supplied in a modified half-strength Hoagland's solution with a N:K ratio of 1:2.4. Destructive harvesting of plants occurred at 14 day intervals at which time plants were separated into their various component parts and analyzed for dry weight accumulation, leaf area index, crop growth rate, relative growth rate and net assimilation rate. Results showed dry weight distribution within the plant had a linear response for all component part evaluated. Greatest contributors to total plant dry weight was stem followed by leaves, fibrous roots, buds and flowers. However, once storage root production occurred it contributed the largest percentage to total plant dry weight. LAI was optimum at 80 days after planting (DAP) while CGR and RGR fluctuated throughout the growing season. Initially NAR was higher in foliage than storage roots but declined once storage root enlargement began, suggesting a translocation of assimilates to storage root.

737 PB 035 l-UN TOMATO PLANTS TREATED WITH EDTA DO NOT PRODUCE FRUITS THAT TURN RED

It has been reported that 90-day old fruit of rin mutant tomato plants treated with nutrient solution containing 1 g EDTA/L attain 98% red coloration of untreated wild-type fruit. We grew rin plants in sand and watered with half-strength Hoagland's solution until flowering. After flowering, plants were watered until run-off daily with full-strength Hoagland's solution (control), full-strength Hoagland's solution with 135 μ M or 2.5 mM Na2EDTA, or full-strength Hoagland's solution lacking calcium. We did not observe any red fruit or measure any differences in ethylene production or soluble polyuronides content. Analyses of pericarp ion content indicated that fruit from plants treated with 2.5 mM Na2EDTA had higher concentrations of sodium and manganese than control fruit. Fruit from plants treated with solution lacking calcium developed blossom end rot and had less calcium and iron than control fruit.

Photosynthesis and chlorophyll fluorescence in sunflower (Helianthus annuus L.) leaves as affected by phosphorus nutrition

The effects of phosphate concentration on plant growth and photosynthetic processes in primary leaves of young sunflower (Helianthus annuus L.) plants were examined. Plants were grown for 3 weeks on half-strength Hoagland's solution containing 0, 0.1, 0.5, 1.0, and 3.0 mol m−3 orthophosphate (Pi). It was shown that optimal photosynthesis and the highest light utilization capacity were achieved at 0.5 mol m−3 Pi in the growth medium, which was in good agreement with the maximum content of organic phosphorus in the leaves. Low phosphate in the medium inhibited plant growth rate. Phosphate deficiency appreciably decreased photosynthetic oxygen evolution by leaves, the efficiency of photosystem two (PSII) photochemistry and quantum efficiency of PSII electron transport. High oxidation state of PSII primary electron acceptor QA, at 0.1 mol m−3 Pi, however, indicates that photosynthetic electron transport through PSII did not limit photosynthesis in Pi-deficient leaves. The results indicate that diminished photosynthesis under sub- and supra-optimal Pi was caused mainly by a reduced efficiency of ribulose 1, 5-bisphosphate (RuBP) regeneration at high light intensities. These results suggest that, under non-limiting C02 and irradiance, photosynthesis of the first pair of leaves could be diminished by both sub- and supra-optimal phosphorus nutrition of sunflower plants.

Responses of greening bean seedling leaves to nitrogen dioxide and nutrient nitrate supply

Phaseolus vulgaris cv. Kinghorn Wax seedlings grown in darkness at 25°C for 7 days with half strength Hoagland's nutrient solution containing no nitrogen, were transferred to lit continouus stirred tank reactors (CSTRs) in atmospheres containing 0 or 0·3 ppm NO 2 and irrigated with a nutrient solution containing 0 or 5 m m nitrate as sole nitrogen source and allowed to grow for a period of up to 5 days in a 14 h photoperiod. Exposure to NO 2 increased total Kjeldahl nitrogen in the leaves. Further, the exposure to NO 2 increased chlorophyll content from day 3 onwards and inhibited the leaf dry weight substantially on days 4 and 5. The primary leaves of the seedlings exposed to 0·3 ppm NO 2 and supplied with nitrate accumulated some nitrite after 5 days of exposure. Some of the seedlings were returned from CSTRs to growth chambers and allowed to grow for a further period of 5 days in a 14 h photoperiod without NO 2. The growth which developed after the NO 2 exposure growth period, as measured by fresh and dry weights of the leaves, was significantly less in NO 2-exposed plants than in nitrate-grown plants. The experiments demonstrate that the leaves of greening seedlings are able to assimilate NO 2 and that a reduction in leaf dry weight by prolonged NO 2 exposure in the presence of nutrient nitrate can be associated with nitrite accummulation, and that NO 2 has a carry-over effect beyond the duration of NO 2 exposure. It is apparent that NO 2 induces some durable biochemical or cytological aberration in the presence of nutrient nitrate, which adversely affects subsequent leaf growth.

Growth, physiological and anatomical responses of two wheat genotypes to waterlogging and nutrient supply

In order to investigate the responses of plant genotypes to waterlogging and nutrient supply, physiological, morphological, and anatomical features were determined for two genotypes of winter wheat (Triticum aestivum), ‘Bayles’ and “Savannah”. Plants were grown in a growth chamber and fertilized with half-strength or full-strength Hoagland's solution during 17 d of waterlogglng. Waterlogging reduced leaf water potential, stomatal conductance, photosynthesis, chlorophyll content, shoot nitrogen content, shoot and root growth for both Bayles and Savannah; however, there were more adverse effects on Bayles than on Savannah. Doubling the concentration of nutrients supplied to the water logged rooting medium reduced the rate of decline in photosynthesis, chlorophyll content, number of nodal roots, and improved shoot nitrogen status and growth, especially for Bayles. Waterlogging reduced the diameter of metaxylem and protoxylem vessels of the nodal roots for both genotypes. Waterlogging enhanced the formation of aerenchyma in the cortical tissue of both seminal and nodal roots, but to a greater extent for Savannah. Additionally, aerenchyma formed continuously along the seminal roots in Savannah. The results indicated that Bayles was more sensitive to waterlogging than Savannah and that increases in nutrient supply to waterlogged plants could alleviate some of the adverse effects of waterlogging.

Salinity effect on root and shoot characteristics of common and tepary beans evaluated under hydroponic solution and sand culture

Abstract The effects of increased salinity [NaCl + CaCl2] on seedling of three tepary and four common bean cultivars/lines, of known resistance and susceptibility at germination stage, grown for thirty‐eight‐days in salinized hydroponic and sand cultures were assessed at electrical conductivity (EC) of 1.89 (control), 4.00, 8.00, and 12.00 dS/m of half strength Hoagland solution inside a glasshouse at 30/25±2°C day/night temperature. The hydroponic culture screening method was more severe than the sand culture method. Common bean cultivars/lines expressed genetic variability to salinity stress at thirty‐eight‐days old seedlings. ‘Badrieh’ was tolerant to salinity as the tolerant tepary bean T#l line under sand culture. However, this was not evident under hydroponic culture. T#l showed salinity injury symptoms at EC = 4 dS/m, while ‘Badrieh’ showed’ no salinity injury symptoms at EC = 4 dS/m. These results indicate that the mechanisms involved for tolerating salinity in the tepary could be different from t...

MANGANESE CRITICAL LEVELS FOR EARLY SWEETPOTATO GROWTH.

The effects of 0.25, 1.0, 2.5, 10, and 100 mg/liter of Mn on sweetpotato [Ipomoea batatas (L.) Lam.] were evaluated in 1990 and 1991 by use the nutrient film technique (NFT). A modified half strength Hoagland solution with MnCl2 as the Mn source was used. Foliage and storage root dry weights declined linearly with increasing Mn concentration in whole plants, the decline occurring when Mn concentration approached 1000 ug/g. Storage root growth was severely restricted when Mn concentration in fibrous root reached 200 ug/g while foliage dry weight showed a more moderate decrease. Mn concentration was higher in the foliage than in fibrous roots. Roots of plants showed browning at higher (10 or 100 mg/liter) Mn concentrations in solution, which was stained blue with benzidine and bleached with oxalic-sulfuric acid solution, indicating the presence of oxidized Mn. Characteristic toxicity symptoms were observed in plants receiving 2.5, (moderate) 10 or 100 mg/liter Mn in solution. These results suggest that a Mn concentration of approximately 1000 ug/g in whole plants and 100 ug/g in fibrous roots are critical concentrations with respect to Mn toxicity in sweetpotato.

The Effect of Zeatin and iso-Pentenyladenine on Root Growth of Pinus pinea L.

Summary Seedlings of Pinus pinea L. growing in half strength Hoagland's nutrient solution were treated for 24 h with different concentrations of zeatin (Z) and iso -pentenyladenine (iP). These cytokinins did not affect tap root length. Lateral root development was inhibited by Z. A low concentration of Z (10 −8 M) increased the root/shoot ratio and total root dry weight. Lateral root development was stimulated by iP. A concentration of 10-6M was the most effective and caused a 40 % increase in most root parameters measured.

EFFECT OF INOCULATION WITH AZOSPIRILLUM BRASILENSE ON FOLIAGE AND STORAGE ROOT YIELD OF SWEETPOTATO GROWN HYDROPONICALLY IN AN NFT SYSTEM

The effect of inoculation of sweetpotato (Ipomea batatas L. (Lam.)) cultivar “TI-82-155” with Azospirillum brasilense was investigated in an observational greenhouse experiment. Sweetpotato was grown in a closed hydroponic system and plant nutrients were supplied in a Modified Half-strength Hoagland's solution (N:K 1:2.4) using a nutrient film technique system (NFT). Plants were either supplied with mineral nitrogen (160 ppm) and noninoculated or were supplied mineral nitrogen (160 ppm) and inoculated. Storage root dry matter was higher under inoculation with A. brasilense. Inoculation also increased the percent total nitrogen in the shoot, leaves, and fibrous root. There was a significant difference in fresh fibrous root weight for the inoculated (262.5 g) over the noninoculated (177.1 g) treatments. Mineral nitrogen supplied in the PNS was not limiting because dry matter for plants inoculated with A. brasilense was not significantly higher than for the noninoculated control.