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Production of methane via anaerobic digestion of energy crops and organic wastes would benefit society by providing a clean fuel from renewable feedstocks. This could replace fossil fuel-derived energy and reduce its environmental impacts, including global warming and acid rain. Although biomass energy is more costly than fossil fuel-derived energy, trends to limit carbon dioxide and other emissions through regulations, carbon taxes, and subsidies of biomass energy would make it cost competitive. Methane derived from anaerobic digestion is competitive in efficiencies and costs with other biomass energy forms including heat, synthesis gases, and ethanol. The objective of this paper is to review the results and conclusions of research on biomass energy conducted under the sponsorship of the gas industry with periodic co-funding from other agencies. The scope of this program was to determine the technical and economic feasibility of production of substitute natural gas (SNG) from marine and terrestrial biomass and organic wastes using anaerobic digestion as a conversion process. This work began in 1968 and continued until about 1990, ending as a result of low energy prices in the U.S. and reduced emphasis on renewable energy. For each of these feedstock categories, growth or collection (in the case of wastes), harvesting, conversion by anaerobic digestion, and systems and economic analysis were addressed. More recently the potential use of anaerobic digestion for stabilization and recovery of nutrients from solid wastes during space missions was studied with funding from NASA. The application of this process for that function as well as treatment of wastewater and waste gases generated during space missions is addressed.

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Boron (B) is often deficient in many fruit crops, including blueberry (Vaccinium sp.). The objective of the present study was to evaluate different methods for applying B fertilizers to two commercial cultivars of northern highbush blueberry (V. corymbosum Earliblue and Aurora) in western Oregon, USA. Treatments included soil application of sodium tetraborate in early April (before bloom), foliar application of boric acid in late April (during bloom or petal fall), weekly fertigation with boric acid from April through July, and a control with no B. The plants were irrigated by drip, and the fertilizers were applied for two consecutive seasons at a total rate of 1.5 kg·ha−1 B per year. Each method of fertilizer application increased the concentration of B in the soil solution relative to the control, but fertigation was the only treatment that increased extractable soil B to the recommended level of 0.5 to 1.0 mg·kg−1 B. In terms of plant nutrition, foliar application of B was the most effective method for increasing the concentration of B in the leaves, roots, and fruit, followed by fertigation. Soil application of B, on the other hand, was relatively ineffective and, after 2 years, only increased the concentration of B in the leaves of ‘Earliblue’. Although leaf B levels were initially deficient at the site (<30 ppm B), none of the B application methods had any effect on yield, berry weight, fruit firmness, or titratable acidity of the fruit in either cultivar. However, foliar applied B resulted in higher concentrations of soluble solids in the fruit than no B or soil applied B in ‘Earliblue’, whereas B fertigation resulted in higher concentrations of soluble solids than soil applied B in ‘Aurora’. On the basis of these results, applying B by fertigation or as a foliar spray is recommended over the use of soil applications of B fertilizer in northern highbush blueberry.

Open Access

`Golden Delicious' apple [Malus sylvestris var. domestica (Borkh.)] cortex disks suspended in solutions containing a nitric oxide (•NO) donor [S-nitrosoglutathione (GSNO) or sodium nitroprusside (SNP)], •NO gas, or nitrite (KNO2) were used to identify impacts of •NO on ethylene production and NO2 on •NO and ethylene production. Treatment with GSNO or SNP reduced ethylene biosynthesis compared with control treatments containing equimolar concentrations of oxidized glutathione (GSSG) or Na4(CN)6 respectively. Apple disk exposure to •NO gas did not impact ethylene production. Treatment with NO2 resulted in increased •NO production and decreased ethylene biosynthesis. Generation of •NO increased linearly whereas ethylene generation decreased exponentially with increasing NO2 treatment concentration. •NO was enhanced in autoclaved tissue disks treated with NO2 , suggesting that its production is produced at least in part by nonenzymatic means. Although this evidence shows •NO is readily generated in apple fruit disks by NO2 treatment, and ethylene synthesis is reduced by •NO/NO2 generated in solution, the exact nature of •NO generation from NO2 and ethylene synthesis modulation in apple fruit disks remains to be elucidated.

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Abstract

‘Sunfre’ nectarine [Prunus persica (L.) Batsch] has been released to provide a large, productive, high quality, attractive nectarine for areas in Florida which has a minimum of 500 chilling hours below 7°C.

Open Access

Abstract

Transplanting is an ancient horticultural practice, which is a good thing because our profession is in need of a transplant—an attitude transplant! I was both encouraged and discouraged as I read Dermot P. Coyne's Presidential Address in the Oct. 1985 issue of HortScience 20:805–808. Encouraged, because he raised points that we need to address; discouraged, because he missed the starting point. Allow me to paraphrase an old saying: “Big grad students from little undergrads grow“. Let me lay it out in the open: I was shocked that our President finds no role for undergraduate education in tackling world hunger. I disagree!

Open Access

Indian mustard trap crops have successfully reduced pesticide use on commercial cabbage in India. Diamondback moth has been a serious pest of cabbage in Texas and has demonstrated resistance to most classes of insecticides. Use of a trap crop could fit well in an integrated management program for cabbage insects, Three-row plots of spring and fall cabbage were surrounded by successive single-row plantings of Indian mustard in trials at Lubbock, Texas to determine the efficacy of interplanting for reducing insecticide applications. Insects in the cabbage and Indian mustard were counted twice weekly, and insecticides were applied selectively when economic thresholds were reached. Indian mustard was highly attractive to harlequin bugs, and protected intercropped spring cabbage. Cabbage plots without mustard required two insecticide applications to control the infestation. False chinch bugs were also highly attracted to Indian mustard. Lepidopterous larvae, including diamondback moth, did not appear to be attracted to the trap crop. Indian mustard trap crops reduced insecticide applications to spring cabbage but had no positive effect on fail cabbage.

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Residues of two fungicides (dodine and fenarimol) and two insecticide/acaricides (amitraz and formetanate) on pear (Pyrus communis L.) leaves were reduced by over-tree sprinkler irrigation applied 24 or 72 hours after pesticide treatment. The difference in residue persistence following over-tree irrigation applied at 24 vs. 72 hours after pesticide treatment was significant only for fenarimol. Residues on leaves from nonirrigated trees at 96 hours post-treatment had declined 24% to 57% from initial levels. Over-tree irrigation further reduced residues by 14% to 47%. For all compounds except dodine, foliar residues measured at 96 hours post-treatment were reduced from initial levels to a greater extent by factors other than over-tree irrigation. Chemical names used: dodecylguanidine monoacetate (dodine); α-(2-chlorophenyl)-α-(4-chlorophenyl)-5-pyrimidinemethanol (fenarimol); N'-(2,4-dimethylphenyl) -N-[[(2,4-dimethylphenyl) imino]methyl] -N-methylmethanimidamide (amitraz); N,N-dimethyl -N'-[3[[(methylamino) carbonyl]oxy]phenyl]methanimidamide (formetanate).

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Abstract

Organic acid components of tissues of grapefruit (Citrus paradisi Macf.) were analyzed by gas-liquid chromatography. At harvest, in autumn, malic acid was the main component of the flavedo (78% of total acid content), with malonic, adipic, citric, succinic and oxalic, ranging in order from 11% to 2%. In the albedo, malic was again the prevalent acid (67%), with malonic, adipic, oxalic and succinic acids ranging in order from 19% to 2%; citric acid was present in traces only. In the juice, citric was the prevalent acid (87%), malic attained 12% while other acids were present only in minute amounts. Malic, malonic, adipic and succinic acids in the flavedo declined when the fruit was left on the tree but increased during off-tree storage. Oxalic acid disappeared from the flavedo during storage. Orange and grapefruit acids are compared.

Open Access

Universities continue to cut budgets and reduce faculty. Such cuts occurred at the Univ. of Nebraska in 1986-87. To ensure that floral design courses would continue to be taught, despite reduction in teaching appointments, an industry-university teaching partnership was proposed. While the teaching relationship started out as a team approach, it successfully evolved into a-strong partnership that permitted growth on the part of the industry instructor, and movement into a strictly supervisory role for the faculty partner. Thus, the overall goal of keeping floral design courses as an integral part of the floriculture curriculum was met without using extensive amounts of faculty time.

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The Virginia Gardener Nutrient Management Education Program addressed non-point, urban-runoff pollution of Virginia's streams, estuaries, and groundwater, and included a calendar aimed at alerting the garden consumer to the connection between overfertilization and water pollution. Over 15,000 calendars were requested.

A survey of calendar recipients was conducted. 1500 persons were chosen at random, a subsequent address check confirmed adequate distribution among the regions of the state. The response rate was 28%. Responses indicated that 91.3% of those surveyed had changed their garden practices in some way because of the calendar. 90% of the respondents indicated that the calendar had shown them a connection between proper gardening techniques and water quality, with 82.2% indicating the calendar had been moderately to greatly successful in showing them this connection.

The 1989 Virginia Gardener Calendar was an effective method of educating garden consumers about the connection between water quality and nutrient runoff, and cultural practices which lessen the need for fertilizer in the home garden.

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