SWEET POTATO GROWTH IN RESPONSE TO RELATIVE HUMIDITY

Growth chamber experiments were conducted to study the physiological and growth response of sweetpotato [Ipomoea batatas (L.) Lam.] to either 50% or 85 % relative humidity (RH). Vine cuttings of T1-155 were grown using the nutrient film technique in a randomized complete-block design with two replications. Temperature regimes of 28/22C were maintained during the light/dark periods with irradiance at canopy level of 600 μmol·m-2·s-1 and a 14/10-hour photoperiod. High RH (85%) increased the number of storage roots per plant and significantly increased storage root fresh and dry weight, but produced lower foliage fresh and dry weight than plants grown at 50% RH. Edible biomass index and linear growth rate (in grams per square meter per day) were significantly higher for plants grown at 85 % than at 50% RH. Leaf photosynthesis and stomatal conductance were higher for plants at 85 % than at 50% RH. Thus, the principal effect of high RH on sweetpotato growth was the production of higher storage root yield, edible biomass, growth rate, and increased photosynthetic and stomatal activity.

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SWEET POTATO GROWTH AND ROOT DEVELOPMENT IN FRITTED CLAY MEDIA

HortScience ◽

10.21273/hortsci.25.8.855 ◽

1990 ◽

Vol 25 (8) ◽

pp. 855F-855

Author(s):

P. J. Ndolo ◽

E. G. Rhoden

Keyword(s):

Sweet Potato ◽

Root Length ◽

Dry Weight ◽

The Other ◽

Root Weight ◽

Storage Root ◽

Fibrous Root ◽

Storage Roots ◽

Potato Growth ◽

Fibrous Roots

Root growth of sweet potato [Ipomoea batatas (L) Lam.] cvs `TI-82-155', `Centennial' and `Rojo Blanco' in coarse fritted clay soil, was investigated under greenhouse conditions. The sweet potato cultivars were harvested at 41 and 82 days after planting. Dry weight of fibrous roots of all cultivars were similar at day 41. Fibrous root weight of `Rojo Blanco' increased by 5% while those of the other cultivars increased by 168%. Mean fibrous root length per centimeter depth was not significantly different among cultivars. Although fresh weight of storage roots of `Rojo Blanco' was significantly lower than those of the other cultivars, their dry weights were similar. `TI-82-155' and `Rojo Blanco' had fewer storage roots compared to the other cultivars, however, storage root length of `TI-82-155' or `Rojo Blanco' was greater than that of `Georgia Jet' or `Centennial'. Length to diameter ratio of the storage root of `Rojo Blanco' was significantly greater than that of `TI-82-155' and `Georgia Jet'.

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SWEET POTATO GROWTH AND ROOT DEVELOPMENT IN FRITTED CLAY MEDIA

HortScience ◽

10.21273/hortsci.25.8.855f ◽

1990 ◽

Vol 25 (8) ◽

pp. 855f-855

Author(s):

P. J. Ndolo ◽

E. G. Rhoden

Keyword(s):

Sweet Potato ◽

Root Length ◽

Dry Weight ◽

The Other ◽

Root Weight ◽

Storage Root ◽

Fibrous Root ◽

Storage Roots ◽

Potato Growth ◽

Fibrous Roots

Root growth of sweet potato [Ipomoea batatas (L) Lam.] cvs `TI-82-155', `Centennial' and `Rojo Blanco' in coarse fritted clay soil, was investigated under greenhouse conditions. The sweet potato cultivars were harvested at 41 and 82 days after planting. Dry weight of fibrous roots of all cultivars were similar at day 41. Fibrous root weight of `Rojo Blanco' increased by 5% while those of the other cultivars increased by 168%. Mean fibrous root length per centimeter depth was not significantly different among cultivars. Although fresh weight of storage roots of `Rojo Blanco' was significantly lower than those of the other cultivars, their dry weights were similar. `TI-82-155' and `Rojo Blanco' had fewer storage roots compared to the other cultivars, however, storage root length of `TI-82-155' or `Rojo Blanco' was greater than that of `Georgia Jet' or `Centennial'. Length to diameter ratio of the storage root of `Rojo Blanco' was significantly greater than that of `TI-82-155' and `Georgia Jet'.

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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.

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EFFECT OF PHOTOPERIOD AND TEMPERATURE REGIMES ON YIELD OF SWEET POTATOES GROWN USING THE NUTRIENT FILM TECHNIQUE (NFT)

HortScience ◽

10.21273/hortsci.25.8.858g ◽

1990 ◽

Vol 25 (8) ◽

pp. 858g-858

Author(s):

Desmond Mortley ◽

Conrad Bonsi ◽

Philip Loretan ◽

Walter Hill ◽

Edwin Martinez

Keyword(s):

Sweet Potato ◽

Constant Temperature ◽

Continuous Light ◽

Storage Root ◽

Sweet Potatoes ◽

Root Numbers ◽

Temperature Regimes ◽

Nutrient Film Technique ◽

Growth Chambers ◽

Hoagland Nutrient Solution

Hydroponic experiments using the nutrient film technique (NFT) were conducted in environmental growth chambers to evaluate the response of two sweet potato cultivars, `Georgia Jet' and `TI-155', to two photoperiod and temperature regimes. Vine cuttings of these cultivars were planted in growth channels supplied with modified half-Hoagland nutrient solution using NFT. Plants were subjected to a 24 h photoperiod or a 12:12 h light:dark photoperiod, a constant temperature of 28C or light:dark temperature of 28/22C. Plants were exposed to irradiance levels of 400 umol m-2 s-1 at canopy level and 70% RH. Storage root fresh and dry weights were increased for both cultivars under the 24 h photoperiod at the 28C constant temperature. `Georgia Jet' storage root numbers were not affected by any treatment while those for `TI-155' were reduced under continuous light for both temperature regimes. Foliage fresh and dry weights were not affected by any treatment.

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High Relative Humidity Increases Yield, Harvest Index, Flowering, and Gynophore Growth of Hydroponically Grown Peanut Plants

HortScience ◽

10.21273/hortsci.35.1.46 ◽

2000 ◽

Vol 35 (1) ◽

pp. 46-48 ◽

Cited By ~ 4

Author(s):

D.G. Mortley ◽

C.K. Bonsi ◽

P.A. Loretan ◽

W.A. Hill ◽

C.E. Morris

Keyword(s):

Relative Humidity ◽

Seed Yield ◽

Harvest Index ◽

Photon Flux ◽

Solution Ph ◽

Seed Maturity ◽

Temperature Regimes ◽

Nutrient Film Technique ◽

Total Seed ◽

Hydroponically Grown

Growth chamber experiments were conducted to study the physiological and growth response of peanut (Arachis hypogaea L.) to 50% and 85% relative humidity (RH). The objective was to determine the effects of RH on pod and seed yield, harvest index, and flowering of peanut grown by the nutrient film technique (NFT). `Georgia Red' peanut plants (14 days old) were planted into growth channels (0.15 × 0.15 × 1.2 m). Plants were spaced 25 cm apart with 15 cm between channels. A modified half-Hoagland solution with an additional 2 mm Ca was used. Solution pH was maintained between 6.4 and 6.7, and electrical conductivity (EC) ranged between 1100 and 1200 μS·cm–1. Temperature regimes of 28/22 °C were maintained during the light/dark periods (12 hours each) with photosynthetic photon flux (PPF) at canopy level of 500 μmol·m–2·s–1. Foliage and pod fresh and dry weights, total seed yield, harvest index (HI), and seed maturity were greater at high than at low RH. Plants grown at 85% RH had greater total and individual leaflet area and stomatal conductance, flowered 3 days earlier and had a greater number of flowers reaching anthesis. Gynophores grew more rapidly at 85% than at 50% RH.

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ALTERING NUTRIENT SOLUTION N:K RATIO TO INCREASE YIELDS OF SWEETPOTATO GROWN IN NFT

HortScience ◽

10.21273/hortsci.29.7.731b ◽

1994 ◽

Vol 29 (7) ◽

pp. 731b-731 ◽

Cited By ~ 1

Author(s):

D.G. Mortley ◽

P A. Loretan ◽

A.A Trotman ◽

P. P David ◽

L.C Garner ◽

...

Keyword(s):

Nutrient Solution ◽

Ipomoea Batatas ◽

Life Support ◽

Block Design ◽

Dry Weight ◽

Culture Solution ◽

Fibrous Root ◽

Storage Roots ◽

Nutrient Film Technique ◽

Long Duration

The effects of altering, nutrient solution N:K ratio on growth of `TI-155' sweetpotato [Ipomoea batatas (L.) Lam] was evaluated in a greenhouse, as part of NASA's Closed Ecological Life Support Systems (CELSS) program for long duration space missions. Vine cuttings of `TI-155', were grown using nutrient film technique (NFT) in a modified half Hoagland's solution in channels (0.15×0.15×1.2 m). Plants were grown for 42 days in a culture solution in which N was doubled (6 mM) in order to accelerate foliage growth after which treatment N:K ratios of 1:2.4, (control) 1:4.8, and 1:7.2 were initiated. A randomized complete block design with 4 replications was used. The number of storage roots/plant increased linearly as K was increased in the solution. Storage root fresh and dry weights, growth rate (g m-2 d-1), fibrous root dry weight, foliage fresh and dry weights, and edible biomass index (root mass/total plant mass), though not significant all increased as K was increased in the nutrient solution. Nutrient solution analyses showed that K uptake was greatest in plants at the highest K level, while nitrate uptake was steady over the duration of crop growth regardless of treatments.

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Evidence That Sweet Potato (Ipomoea batatas) is Allelopathic to Yellow Nutsedge (Cyperus esculentus)

Weed Science ◽

10.1017/s0043174500071654 ◽

1991 ◽

Vol 39 (2) ◽

pp. 308-312 ◽

Cited By ~ 13

Author(s):

Howard F. Harrison ◽

Joseph K. Peterson

Keyword(s):

Sweet Potato ◽

Ipomoea Batatas ◽

Cultural Practices ◽

Dry Weight ◽

Field Studies ◽

Competitive Effects ◽

Yellow Nutsedge ◽

Shoot Dry Weight ◽

Shoot Weight ◽

Potato Growth

In field studies, ‘Regal’ sweet potato greatly reduced yellow nutsedge growth when the two species were grown together using standard cultural practices. At the end of the growing season, yellow nutsedge shoot dry weight per m2in plots where the two species were planted together was less than 10% of shoot weight in plots where nutsedge was grown alone. Presence of yellow nutsedge did not markedly affect sweet potato growth. When grown together in a greenhouse experiment designed to minimize the competitive effects of sweet potato on yellow nutsedge, yellow nutsedge growth was reduced more than 50% by sweet potato 8 and 12 weeks after planting. The most polar fraction of serially extracted sweet potato periderm tissue was highly inhibitory to yellow nutsedge root growth. These results indicate that sweet potato interference with yellow nutsedge under field conditions is partially due to allelopathy.

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Metabolic signalling and the partitioning of resources in plant storage organs

The Journal of Agricultural Science ◽

10.1017/s0021859699006978 ◽

1999 ◽

Vol 133 (3) ◽

pp. 243-249 ◽

Cited By ~ 3

Author(s):

NIGEL G. HALFORD

Keyword(s):

Dry Weight ◽

Wild Relatives ◽

Crop Plants ◽

Wild Plants ◽

Young Plant ◽

Carbon And Nitrogen ◽

Cultivated Potato ◽

Metabolic Signalling ◽

Storage Organs ◽

Plant Storage

The most important harvested organs of crop plants, such as seeds, tubers and fruits, are often described as assimilate sinks. They play little or no part in the fixation of carbon through the production of sugars through photosynthesis, or in the uptake of nitrogen and sulphur, but import these assimilated resources to support metabolism and to store them in the form of starch, oils and proteins. Wild plants store resources in seeds and tubers to later support an emergent young plant. Cultivated crops are effectively storing resources to provide us with food and many have been bred to accumulate much more than would be required otherwise. For example, approximately 80% of a cultivated potato plant's dry weight is contained in its tubers, ten times the proportion in the tubers of its wild relatives (Inoue & Tanaka 1978). Cultivation and breeding has brought about a shift in the partitioning of carbon and nitrogen assimilate between the organs of the plant.

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