Sweet potato for closed ecological life support systems using the nutrient film technique

Sweet potatoes were grown hydroponically using the nutrient film technique (NFT) in support of the Closed Ecological Life Support System (CELSS) program. Experiments in the greenhouse with the TI-155 sweet potato cultivar produced up to 1790 g/plant of fresh storage roots. Studies with both TI-155 and Georgia Jet cultivars resulted in an edible biomass index of approximately 60 percent, with edible biomass linear growth rates of 12.1 to 66.0 g m(exp -2)d(exp -1) in 0.05 to 0.13 sq meters in 105 to 130 days. Additional experimental results are given. All studies indicate good potential for sweet potatoes in CELSS

Where Nothing Happened: The Experience of War Captivity and Levinas’s Concept of the ‘There Is’

This article takes as its subject matter the juridico-political space of the prisoner of war (POW) camp. It sets out to determine the nature of this space by looking at the experience of war captivity by Jewish members of the Western forces in World War II, focusing on the experience of Emmanuel Levinas, who spent 5 years in German war captivity. On the basis of a historical analysis of the conditions in which Levinas spent his time in captivity, it argues that the POW camp was a space of indifference that was determined by the legal exclusion of prisoners from both war and persecution. Held behind the stage of world events, prisoners were neither able to exercise their legal agency nor released from law into a realm of extra-legal violence. Through a close reading of Levinas’s early concept of the ‘there is’ [il y a], the article seeks to establish the impact on prisoners of prolonged confinement in such a space. It sets out how prisoners’ subjectivity dissolved in the absence of meaningful relations with others and identifies the POW camp as a space in which existence was reduced to indeterminate, impersonal being

Effect of Timing of Fertilizer Application on Yield, Quality and Elemental Leaf Concentration of Transplanted Fresh Market Tomato

Abstrac

Split-Root Nutrition of Sweetpotato in Hydroponic Systems

Nutrient film technique (NFT) and deep water culture (DWC) hydroponic systems were used in a split-root study of the effect of four treatments on sweetpotato yield, the translocation of assimilates, and microbial population count. ‘TU-155’ cuttings (15 cm) were prerooted for 30 days in sand using deionized water and a modified half-Hoagland (MHH) solution. After 30 days, the plants were removed, and the roots of each were cleaned and split evenly between two sides of a channel (each 15 cm deep by 15 cm wide by 1.2 m long), four plants per channel. Replicated treatments were: MHH/MHH; MHH/Air, MHH/deionized water (DIW); and monovalent/divalent anions and cations (Mono/Dival). The entire experiment was repeated. Plants were harvested after growing for 120 days in a glasshouse. Storage roots, when produced, were similar in nutritive components. However, no storage roots were produced in Air or Mono channels and only a few in DIW suggesting inhibition of assimilate translocation. Fresh and dry weights for storage roots and foliage were highest in MHH/MHH in both NFT and DWC in both experiments. Solution samples were collected at 14-day intervals for microbial population profiling. Microbial counts (4.20–7.49 log cfu/ml) were highest in Dival channels. The counts indicated that solution composition influenced population size, and they were relatively high in both systems

RESPONSE OF SWEETPOTATO GROWN IN NUTRIENT FILM TECHNIQUE (NFT) TO BLUE LIGHT

An experiment was conducted in controlled environment chambers to evaluate the effect of varying levels of blue light on vine growth and storage root yield of sweetpotato [ I p o m o e a batatas (L.) Lam.] when grown in nutrient film technique (NFT). Cuttings of'TU-82-155" sweetpotato were grown under 6, 11, 16, 22.5, and 26% blue light (320-496 nm) supplied by high intensity discharge metal halide and high pressure sodium lamps. Total fresh mass was greatest for plants grown under 22.5 or 26% , and lowest for plants under 11% blue light. Total plant dry mass and storage root yield, however, were similar among treatments. Harvest index (storage root dry mass/total plant dry mass) was highest for plants grown under 26% blue light. Plants grown under 26% blue light tended to have a higher growth rate. Both vine and internode length tended to decline as the percentage of blue photons increased. These results indicate that storage root yield was not adversely affected by exposure to blue light as high as 26%, and that the main effect of blue light was to cause a reduction in vine length

Peanut (Arachis hypogaea L.) Growth and Yield Using the Nutrient Film Technique

Peanut plants, cvs 'Georgia Red' (GARBO) andNew Improved Spanish (NISP), were grown in polyvinyl chloride (PVC-I) trays using the nutrient film technique to study pod and seed yield for NASA's Advanced Life Support (ALS) program. Four 14-day-old seedlings each of both genotypes were transplanted into each of two growth trays (0.15 x 0.15 x 1.2 m), allotting 0.045 m2 per plant for growth. Plants were grown in reach-in growth chambers with a diurnal temperature of28/22°C, relative hwnidity of70 +5%, 12/12 h photoperiod, irradiance at canopy Icvel of 600 ?mol m-2 s-I, and a C02 concentration of 700 ?mol mol-L A modified half Hoagland nutrient solution was used. Solution pH was adjusted manually and ranged between 6.4 and 6.7, by additions of 1M NaOIl or HCI. Solution electrical conductivity (EC) ranged between 1100 and 1200 ?S em-I. All plants were harvested after 120 days. Total mean plant fresh weight was 546.5 g and 769.0 g per tray, respectively, for Georgia Red and New Improved Spanish. The total number ofpods and pod fresh weight per tray averaged 152 and 190 g forGR and 138 and 154 g for NISP, while seed dry mass averaged 70 g and 81 gper tray, respectively, for GAREO and NIS. The harvest index was 0.39 for GR and 0.36 for NISP. Seed yield was equivalent to or exceeded that of field-grown peanuts. Generally, the proximate nutrient composition was similar to that of field-grown peanuts. The results demonstrate that the nutrient film technique CBLn be used for peanut production with acceptable yields