IMPACT OF NUTRIENT REPLENISHMENT ON HYDROPONIC SWEETPOTATO CULTURE

In a greenhouse experiment, the effect of the addition of higher levels of potassium (K) in the replenishment stock used to supply nutrients in a nutrient film technique system was examined. For this study, `TU-82-155' sweetpotato was grown hydroponically for 120 days under four nutrient application/replenishment treatments: 1) REG—solution was changed at 14-day intervals and volume allowed to fluctuate; 2) MHH—replenishment with 10× concentrate of a modified half Hoagland solution (MHH) or with water to regain set volume (30.4 liters) and maintain set point of electrical conductivity (EC, 1050–1500 μmho); 3) MHH + 2K—daily replenishment with 10× concentrate of a modified half Hoagland solution (MHH) or with water to regain the set volume and adjust EC to 1400 followed by application of 50 ml of a 2K stock solution to an EC of 1500; 4) MHH/2K—replenishment with 10× concentrate of a modified half Hoagland solution that incorporated the 2K component or with water to regain set volume (30.4 liters) and maintain set point of electrical conductivity (EC, 105–1500 μmho). The storage root yield (g fresh weight per plant) was significantly higher when the 2K treatment was incorporated with the 10× MHH stock. The storage root yield averaged 324.8 g/plant compared with a yield of 289.6 and 252.9 g/plant, respectively, for the REG and MHH nutrient application protocol. As in earlier experiments, the MHH treatment was comparable to the REG protocol, validating the use of a replenishment approach for nutrient supply in hydroponic sweetpotato culture.

Download Full-text

RESPONSES OF SEVERAL SWEETPOTATO GENOTYPES TO SOLUTION REPLENISHMENT IN HYDROPONIC CULTURE

HortScience ◽

10.21273/hortsci.31.5.761a ◽

1996 ◽

Vol 31 (5) ◽

pp. 761a-761

Author(s):

P.P. David ◽

C.K. Bonsi ◽

D.Z. Douglas

Keyword(s):

Dry Mass ◽

Storage Root ◽

Large Reservoir ◽

Nutrient Film Technique ◽

Nutrient Replenishment ◽

Half Strength ◽

Small Container ◽

Main Plot ◽

Daily Water ◽

Large Container

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.

Download Full-text

EFFECT OF SPACING ON YIELD OF SWEET POTATOES GROWN USING THE NUTRIENT FILM TECHNIQUE (NFT)

HortScience ◽

10.21273/hortsci.25.8.857g ◽

1990 ◽

Vol 25 (8) ◽

pp. 857g-857

Author(s):

Desmond Mortley ◽

Conrad Bonsi ◽

Philip Loretan ◽

Walter Hill ◽

Carlton Morris

Keyword(s):

Sweet Potato ◽

Root Number ◽

Storage Root ◽

Growth Responses ◽

Sweet Potatoes ◽

Hoagland Solution ◽

Greenhouse Experiments ◽

Nutrient Film Technique ◽

Potato Growth

Greenhouse experiments were conducted to evaluate the effects of spacing within and between growth channels on the yield of `TI-1551 sweet potatoes grown hydroponically using the nutrient film technique (NFT). Spacings within channels were 12.7, 17.8 and 25.4 cm whereas between growth channels the spacings were 12.7, 25.4 and 38.1 cm. Vine cuttings (15 cm) placed in each channel (0.15×0.15×1.2 m) were supplied with a modified half-Hoagland solution and grown for 120 days. Storage root number, fresh and dry weights and foliage fresh and dry weights tended to increase as spacing between channels increased. Spacing of plants within channels had no significant effect on any sweet potato growth responses.

Download Full-text

Influence of Daily Light Period and Irradiance on Yield and Leaf Elemental Concentration of Hydroponically Grown Sweetpotato

HortScience ◽

10.21273/hortsci.44.5.1491 ◽

2009 ◽

Vol 44 (5) ◽

pp. 1491-1493 ◽

Cited By ~ 6

Author(s):

Desmond G. Mortley ◽

Stephanie Burrell ◽

Conrad K. Bonsi ◽

Walter A. Hill ◽

Carlton E. Morris

Keyword(s):

Elemental Concentration ◽

Dilution Effect ◽

Light Period ◽

Photon Flux ◽

Stem Cuttings ◽

Storage Root ◽

Root Yield ◽

Nutrient Film Technique ◽

Calcium Magnesium ◽

Lower Irradiance

Growth chamber experiments were conducted to evaluate the effect of irradiance and daily light period on storage root yield and leaf elemental concentration of two sweetpotato cultivars grown hydroponically by use of the nutrient film technique (NFT). Stem cuttings (15 cm) of cv. Whatley/Loretan and Georgia Jet were grown in NFT channels (0.15 × 0.15 × 1.2 m) in reach-in growth chambers under light period/irradiance combinations of 18 h: 300 μmol·m−2·s−1 or 9 h: 600 μmol·m−2·s−1 photosynthetic photon flux. Temperature was 28/22 °C light/dark with a relative humidity of 70% ± 5%. Storage root and foliage yields were greater in both cultivars exposed to a longer daily light period and lower irradiance. The main effect of cultivar indicated that storage root yield was significantly greater among plants of ‘Whatley/Loretan’ compared with that of ‘Georgia Jet’, whereas foliage yield was similar between cultivars. Leaves of plants grown under longer daily light period and lower irradiance had significantly lower concentrations of all elements, nitrogen, phosphorus, potassium, calcium, magnesium, manganese, iron, calcium, boron, and zinc, except for calcium, manganese, and boron. There were no significant differences in leaf elemental concentration between cultivars. Thus, a longer daily light and lower irradiance enhanced biomass production of sweetpotato but reduced leaf elemental concentration probably because of a “dilution” effect.

Download Full-text

IMPLICATIONS OF THE CONTINUOUS USE OF PLANT NUTRIENT SOLUTION ON GROWTH OF SWEETPOTATO IN NFT

HortScience ◽

10.21273/hortsci.30.3.429b ◽

1995 ◽

Vol 30 (3) ◽

pp. 429b-429

Author(s):

Audrey A. Trotman ◽

P.P. David ◽

D.G. Mortley ◽

D. Douglas

Keyword(s):

Management Strategy ◽

Leaf Biomass ◽

Storage Root ◽

Root Yield ◽

Set Point ◽

Nutrition Management ◽

Greenhouse Study ◽

Waste Production ◽

Continuous Use ◽

Application Protocols

In developing a nutrition management strategy that reduces the quantity of products entering the waste management stream, gaining an understanding of the patterns and fluctuations of nutrient levels and crop growth characteristics is essential. In a greenhouse study, `TU-82-155' sweetpotato was grown hydroponically for 120 days in three nutrient application–replenishment treatments: l) REG-solution changed at 14-day intervals and volume allowed to fluctuate; 2) daily replenishment with 10× concentrate of a modified quarter Hoagland's solution (MQH) or with water to regain set volume (30.4 liters) and maintain set point of electrical conductivity [(EC); 1050 to 1200 μmho]; 3) daily replenishment with l0× concentrate of a modified half Hoagland's solution (MHH) or with water to regain the set volume and maintain the set point of EC. There were no statistically significant differences among nutrient application protocols for storage root count, fresh and dry weights, and percent dry matter. The MHH treatment consistently yielded significantly higher leaf biomass and pencil roots (>1 mm in diameter), indicating a higher potential for increased storage root yield. A nutrient application protocol using treatment 2 has potential for reduced waste production if used in hydroponic sweetpotato production. The plants from the MQH treatment initiated vegetative buds at a significantly later date than in the other treatments and generally showed evidence of suppressed plant development.

Download Full-text

EFFECT OF CONTINUOUS VS PERIODIC pH ADJUSTMENT ON GROWTH OF `GEORGIA JET' AND `T1-155' SWEET POTATO CULTIVARS GROWN USING THE NUTRIENT FILM TECHNIQUE (NFT)

HortScience ◽

10.21273/hortsci.25.8.864c ◽

1990 ◽

Vol 25 (8) ◽

pp. 864c-864 ◽

Cited By ~ 1

Author(s):

Edwin Martinez ◽

Conrad Bonsi ◽

Phili p Loretan ◽

Walter Hill ◽

Desmond Mortley ◽

...

Keyword(s):

Sweet Potato ◽

Nutrient Solution ◽

Life Support ◽

Growth Period ◽

Potato Cultivars ◽

Storage Root ◽

Root Yield ◽

Solution Ph ◽

Ph Adjustment ◽

Nutrient Film Technique

Sweet potato, selected as a potential food source for future long-term manned space missions, is being evaluated for NASA's Controlled Ecological Life Support Systems (CELSS) program. Greenhouse experiments were conducted to determine the effects of two pH treatments on the growth and storage root yield of `T1-155' and `Georgia Jet ' sweet potato cultivars. Vine cuttings of these cultivars were grown in a specially designed Tuskegee University NFT system. Plants were subjected to a continuous pH treatment in which the nutrient solution pH was maintained at 5.00 ± 0.10 throughout the growth period, and a periodic pH treatment in which the nutrient solution pH was adjusted to 6.00 at biweekly changeover intervals and when reservoirs were refilled with deionized water between biweekly changeovers. Results showed that for both cultivars the treatment with periodic pH adjustment had significantly higher storage root yield than treatment with continuous pH adjustment. This experiment is being repeated.

Download Full-text

Foliage Removal Influences Sweetpotato Biomass Yields in Hydroponic Culture

HortScience ◽

10.21273/hortsci.30.5.1000 ◽

1995 ◽

Vol 30 (5) ◽

pp. 1000-1002 ◽

Cited By ~ 4

Author(s):

P.P. David ◽

A.A. Trotman ◽

D.G. Mortley ◽

C.K. Bonsi ◽

P.A. Loretan ◽

...

Keyword(s):

Growth Rate ◽

Ipomoea Batatas ◽

Linear Growth ◽

Canopy Cover ◽

Linear Growth Rate ◽

Shoot Biomass ◽

Storage Root ◽

Root Yield ◽

Nutrient Film Technique ◽

Half Strength

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.

Download Full-text

SWEETPOTATO GROWTH AND YIELD IN NFT AS AFFECTED BY TYPE OF CUTTING AND PLANTING DEPTH

HortScience ◽

10.21273/hortsci.28.4.267f ◽

1993 ◽

Vol 28 (4) ◽

pp. 267F-267

Author(s):

Lauren Garner ◽

Desmond Mortley ◽

Philip Loretan ◽

Audrey Trotman ◽

Pauline David

Keyword(s):

Shoot Apex ◽

Dry Matter ◽

Growth And Yield ◽

Storage Root ◽

Root Yield ◽

Yield Data ◽

Planting Depth ◽

Ipomea Batatas ◽

Nutrient Film Technique ◽

The Relationship

An experiment was conducted in a greenhouse environment to determine the relationship between type of cutting and planting depth on sweetpotato [Ipomea batatas (L) Lam] storage root yield using the nutrient film technique. Vine cuttings of the cultivar 'TI-155' were planted in growth channels (122×15×15 cm) in modified half Hoagland's solution. Treatments consisted of cuttings with all leaves and shoot apex removed with two nodes inserted (2NB), cuttings with all leaves and shoot apex removed with five nodes inserted (5NB). and cuttings with four leaves and the shoot apex remaining with two nodes inserted (2NB-L). Plants were harvested 130 days after planting and yield data was taken. Plants in 2NB-L had a significantly lower percent dry matter than those of 2NB. Neither cutting type nor planting depth affected yield or yield related parameters.

Download Full-text

PHOTOPERIOD/LIGHT INTENSITY INTERACTIONS ON GROWTH OF TWO SWEETPOTATO CULTIVARS IN NFT

HortScience ◽

10.21273/hortsci.28.4.267d ◽

1993 ◽

Vol 28 (4) ◽

pp. 267D-267

Author(s):

S. Burrell ◽

D. Mortley ◽

P. Loretan ◽

L. Garner ◽

A. Trotman ◽

...

Keyword(s):

Light Intensity ◽

Ipomoea Batatas ◽

Block Design ◽

Dry Weight ◽

Storage Root ◽

Fresh Weight ◽

Fibrous Root ◽

Nutrient Film Technique ◽

Randomized Complete Block Design ◽

Lower Light

The effects of photoperiod and light intensity on two sweetpotato cultivars [Ipomoea batatas (L.) Lam] were evaluated in growth chambers. Vine cuttings of `TI-155' and `GA Jet' were grown using nutrient film technique (NFT) in a modified half Hoaglands solution with a 1:2.4 N:K ratio in channels (0.15×0.15×1.2 m). Plants were exposed to 9:600 or 18:300 umols m-2 s-1 photoperiod:light intensity treatments in a randomized complete block design with two replications. Temperature was set at 28:22 light:dark and RH was 70%. Storage root fresh and dry weights and fibrous root dry weight for both cultivars were significantly higher for plants exposed to longer photoperiod and lower light intensity than for those at a shorter photoperiod and higher light intensity. Foliage fresh weight for TI-155' was higher at 18:300 photoperiod:light intensity but dry weights were similar. Foliage fresh and dry weights for `GA Jet' and number of storagage roots/plant for both cultivars were similar regardless of treatments.

Download Full-text