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

HortScience ◽  
1996 ◽  
Vol 31 (2) ◽  
pp. 209-212 ◽  
Author(s):  
D.G. Mortley ◽  
P.A. Loretan ◽  
W.A. Hill ◽  
C.K. Bonsi ◽  
C.E. Morris
Keyword(s):  
Ipomoea Batatas ◽  
Production Efficiency ◽  
Elemental Concentration ◽  
Light Period ◽  
Photon Flux ◽  
Storage Root ◽  
Growth Responses ◽  
Area Index ◽  
Nutrient Film Technique ◽  
Half Strength

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.

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

HortScience ◽  
2009 ◽  
Vol 44 (5) ◽  
pp. 1491-1493 ◽  
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.

scholarly journals RESPONSE OF OF SWEETPOTATO GROWN IN NFT TO DIFFERENT PHOTOPERIODS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 665f-665
Author(s):  
D. G. Mortley ◽  
C. K. Bonsi ◽  
W. A. Hill ◽  
P. A. Loretan ◽  
C. E. Morris ◽  
...  
Keyword(s):  
Ipomoea Batatas ◽  
Dry Weight ◽  
Root Number ◽  
Storage Root ◽  
Growth Responses ◽  
Storage Roots ◽  
Area Index ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
And Storage

Growth chamber studies were conducted to determine growth responses of sweetpotato [Ipomoea batatas (L.) Lam) to differing photoperiods (PP) when grown by use of NFT. Four vine cuttings (15 cm length) of GA Jet and TI-155 were grown for 120 days at 12/12, 15/9, 18/6, and 21/3 light/dark PP. Irradiance averaged 427 umol m-2 s-1, with day/night temperatures of 28/22C and 70% RH. A modified half Hoagland's solution was used. Number of storage roots/plant, and storage root fresh and dry weights for GA Jet increased as PP increased from 12 to 21 h, while storage root fresh and dry weights for TI-155 increased up to 18 h PP but declined at 21 h PP. Storage root number/plant for TI-155 declined at 15 h PP but was higher at both 18 and 21 h PP. Highest foliage dry weight for GA Jet was obtained at 21 h PP while that for TI-155 was obtained at 18 h PP. Leaf area index (LAI) for GA Jet increased with increased PP, while LAI for TI-155 increased with increased PP up to 18 h then declined at 21 h PP.

scholarly journals Failure Analysis under Electric Lights: Growth and Yield of Sweetpotato in Response to 14 Days of Prolonged Darkness

HortScience ◽  
2016 ◽  
Vol 51 (12) ◽  
pp. 1479-1481
Author(s):  
Desmond G. Mortley ◽  
Douglas R. Hileman ◽  
Conrad K. Bonsi ◽  
Walter A. Hill ◽  
Carlton E. Morris
Keyword(s):  
Ipomoea Batatas ◽  
Dry Weight ◽  
Growth And Yield ◽  
Photon Flux ◽  
Storage Root ◽  
Growth Responses ◽  
Root Yield ◽  
Fibrous Root ◽  
Storage Roots ◽  
The Impact

Two sweetpotato [Ipomoea batatas (L.) Lam] genotypes (TU-82-155 and NCC-58) were grown hydroponically and subjected to a temporary loss of lighting in the form of 14 days of prolonged darkness compared with a lighted control under standard daily light periods to determine the impact on growth responses and storage root yield. Vine cuttings of both genotypes were grown in rectangular channels. At 65 days after planting, lights were turned off in the treatment chambers and replaced by a single incandescent lamp, providing between 7 and 10 µmol·m−2·s−1 photosynthetic photon flux (PPF) for 18 hours, and the temperature lowered from 28/22 °C light/dark, to a constant 20 °C. Plants remained under these conditions for 14 days after which the original light level was restored. Growth chamber conditions predark included, a PPF mean provided by 400-W metal halide lamps, of 600 ± 25 µmol·m−2·s−1, an 18-hour light/6-hour dark cycle and a relative humidity of 70% ± 5%. The nutrient solution used was a modified half-Hoagland with pH and electrical conductivity (EC) maintained between 5.5–6.0 and 1000–1200 μS·cm−1, respectively, and was adjusted weekly. Storage root number and fresh weight were similar regardless of treatments. Plants exposed to prolonged darkness produced 10.5% and 25% lower fibrous root fresh and dry mass, respectively, but similar foliage yield and harvest index (HI). ‘NCC-58’ produced an average of 31% greater storage root yield than that of ‘TU-82-155’ but the number of storage roots as well as % dry matter (%DM) were similar. ‘NCC-58’ also produced 31% greater fibrous root dry weight, whereas ‘TU-82-155’ produced a 44% greater HI. The significant interaction between prolonged darkness and cultivars for %DM of the storage roots showed that DM for ‘TU-82-155’ was 18.4% under prolonged darkness and 17.9% in the light. That for ‘NCC-58’ was 16.4% under prolonged darkness compared with 19.4% (14.8% greater) for plants that were not subjected to prolonged darkness. The evidence that there were no adverse impacts on storage root yield following the exposure to prolonged darkness suggests that the detrimental effects were below the detectable limits for these cultivars in response to the short perturbation in the available light and that sweetpotatoes would be hardy under short-term failure situations.

scholarly journals Foliage Removal Influences Sweetpotato Biomass Yields in Hydroponic Culture

HortScience ◽  
1995 ◽  
Vol 30 (5) ◽  
pp. 1000-1002 ◽  
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.

scholarly journals RESPONSES OF SEVERAL SWEETPOTATO GENOTYPES TO SOLUTION REPLENISHMENT IN HYDROPONIC CULTURE

HortScience ◽  
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.

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

HortScience ◽  
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.

scholarly journals 232 Inverse Day/Night Temperature Influences Yield and Canopy Height of Hydroponically Grown Sweetpotato

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 431B-431 ◽  
Author(s):  
D.G. Mortley ◽  
J.H. Hill ◽  
C.K. Bonsi ◽  
W.A. Hill ◽  
C.E. Morris
Keyword(s):  
Canopy Height ◽  
Growth Chamber ◽  
Photon Flux ◽  
Root Production ◽  
Storage Root ◽  
Night Temperature ◽  
Nutrient Film Technique ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
Hydroponically Grown

Growth chamber studies were conducted to determine if inverse day/night temperature could control canopy height of sweetpotato without adversely affecting storage root yield. Four 15-cm-long vine cuttings of TU-82-155 sweetpotato were grown in rectangular nutrient film technique hydroponic troughs for 120 days. Two troughs were placed into each of six reach-in growth chambers and subjected to 24/18, 26/20, 28/22, 18/24, 20/26, and 22/28 °C, respectively. Growth chamber conditions included a 12/12-h photoperiod, 70% RH, and photosynthetic photon flux of 1000 μmol·m-2·s-1 at canopy level. Total and edible storage root yields were reduced by 50% among plants grown under cool days/warm nights regimes. Harvest index was similar among treatments except for the low value obtained at 22/28 °C. Canopy height was positively correlated with the change in temperature, and for every 2 °C decrease there was a 3.1 centimeter decrease in canopy height. Inverse day/night temperature effectively controlled canopy height but at the expense of storage root production.

Low-level Irradiance during the Dark Period Prevents Photoperiodic-induced Tuberization of Potato

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 542b-542 ◽  
Author(s):  
N.C. Yorio ◽  
G.W. Stutte ◽  
R.M. Wheeler ◽  
L.M. Ruffe
Keyword(s):  
Dark Period ◽  
Light Period ◽  
Photon Flux ◽  
Dark Light ◽  
Fluorescent Lamps ◽  
Light Levels ◽  
Nutrient Film Technique ◽  
Early Maturing ◽  
Metal Halide Lamps ◽  
Inductive Photoperiod

The threshold irradiance during the dark portion of a photoperiod required to inhibit tuberization of potato (Solanum tuberosum L.) was investigated. Two cultivars of potato (cv. Norland, an early maturing variety; cv. Russett Burbank, a late-maturing variety) were grown using nutrient film technique hydroponics in separate tests within a walk-in growth chamber under a normally tuber-inductive photoperiod (12-h light/12-h dark). Light period photosynthetic photon flux (PPF) was provided by either daylight fluorescent lamps (providing 150 μmol·m–2·s–1 PPF) or a combination of daylight fluorescent and metal halide lamps (providing 300 μmol·m–2·s–1 PPF). The chamber was configured with vertically hung shadecloth and a pair of 15-W cool-white fluorescent lamps mounted at one end of the chamber to provide a range of low irradiance during the dark period. The low irradiance treatments averaged 3.65, 0.43, 0.06, and <0.01 μmol·m–2·s–1 PPF for the entire 12-h “dark” period. Results showed that tuberization occurred around 23 DAP, regardless of cultivar or light period PPF for plants grown with 0.06 and <0.01 μmol·m–2·s–1 PPF during the dark period. Tuberization also occurred at around 30 DAP for cv. Norland grown with 0.43 μmol·m–2·s–1 PPF during the dark period. No tubers were formed for either cultivar grown with 3.65 μmol·m–2·s–1 PPF during the dark period. These results indicate that light levels <0.43 μmol·m–2·s–1 PPF do not influence photoperiodic induction of tuberization in potato.

scholarly journals Relationship of Photosynthesis and Harvest Index to Sweet Potato Yield

1990 ◽  
Vol 115 (2) ◽  
pp. 288-293 ◽  
Author(s):  
Ajmer S. Bhagsari ◽  
Doyle A. Ashley
Keyword(s):  
Sweet Potato ◽  
Harvest Index ◽  
Ipomoea Batatas ◽  
Field Experiments ◽  
Storage Root ◽  
Canopy Photosynthesis ◽  
Storage Roots ◽  
Physiological Basis ◽  
Area Index ◽  
Stage Of Development

Field experiments with 15 sweet potato [Ipomoea batatas L. (Lam.)] genotypes were conducted to study the physiological basis of yield in 1981 and 1982. The leaf area index differed significantly among the sweet potato genotypes during early and late phases of growth, hut showed an inconsistent relationship with yield. Single leaf net photosynthesis ranged from 0.74 to 1.12 mg CO2/m' per sec. Canopy photosynthesis for sweet potato genotypes differed significantly in 1981, but not in 1982. It ranged from 0.81 to 1.16 mg CO2/m2 per sec in Aug. 1981. and from 0.63 to 0.88 mg CO2/m2 per sec in 1982. Four hours after “C-labeling, 14C-assimilate translocation from the treated leaf ranged from 21% to 46%, but did not differ significantly among the genotypes. At final harvest, harvest index [HI, defined as (storage root yield/total biological yield) × 100] of the genotypes varied from 43% to 77% and 31% to 75% for 1981 and 1982, respectively. Canopy photosynthesis during September was significantly correlated with storage root dry matter yield (r = 0.54*) in 1981 and with phytomass (above-ground biomass plus storage roots) (r = 0.60*) in 1982. Both phytomass and HI were significantly correlated with storage root matter yield. Canopy photosynthetic evaluation of sweet potato germplasm may be-more relevant when the storage root sinks are at an advanced stage of development. Our study suggests that yield is poorly predicted by Pn, particularly when the genotypes have different leaf sizes.

scholarly journals Manganese Toxicity and Tolerance in Sweetpotato

HortScience ◽  
1993 ◽  
Vol 28 (8) ◽  
pp. 812-813 ◽  
Author(s):  
Desmond G. Mortley
Keyword(s):  
Ipomoea Batatas ◽  
Plant Roots ◽  
Manganese Concentration ◽  
Storage Root ◽  
Foliar N ◽  
Nutrient Film Technique ◽  
Whole Plants ◽  
Fibrous Roots ◽  
And Storage ◽  
Mn Concentration

The effects of 0.25, 1.0, 2.5, 10, and 100 mg Mn/liter on sweetpotato [Ipomoea batatas (L.) Lam] were evaluated in a greenhouse during 2 years using the nutrient film technique. Foliage and storage root dry weights declined linearly as Mn concentration increased in either whole plants or fibrous roots. Foliage and storage root dry weights were equally sensitive to Mn concentration in whole plants but 5 to 15 times more sensitive to increased Mn concentration in the fibrous roots. Foliar N, P, K, Ca, and Mg concentrations were adequate and did not appear to limit plant growth. Manganese concentrations in solution had very little effect on Fe, Zn, or B concentration. Manganese concentration was higher in the foliage than in fibrous roots. Plant roots showed browning at the higher (10 or 100 mg Mn/liter) concentrations in solution, which indicated the presence of oxidized Mn. Characteristic toxicity symptoms were observed in plants receiving 2.5 (moderate), 10, or 100 mg Mn/liter in solution.

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