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  • Author or Editor: G.G. Taylor x
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Potato (Solanum tuberosum L.) is one of the major food crops of the world and ranks fourth after rice (Oryza sativa L.), wheat (Triticum aestivum L.), and corn (Zea mays L.) in production. Potato production is concentrated in the temperate zone and in tropical areas, especially at higher elevations. It is of vital interest to study cultural practices associated with potato due to the global importance of this crop. In particular, emphasis will be placed on methods to propagate the potato.

Open Access
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High seed quality is required to obtain optimal plant stands and to achieve maximum yield potential. Onion seeds are commonly coated and treated with an insecticide and fungicide to control early season insects and diseases. The seed treatments may cause phytotoxicity in standard germination tests, and thus reduce the percent germination of a seed lot. The objective of this study was to examine the effect of seed quality on seed storage, stand establishment and yield. Two seed lots of two long-day onion varieties were pelleted and treated with the seed treatments Trigard and Pro-Gro. Standard germination and saturated salt aging tests were performed on each seed lot, indicating a high and lower quality seed lot for each variety. Aging was conducted by equilibrating pelleted seeds at 35% relative humidity and aging at 25 °C for up to 12 months. Aging decreased germination with time, especially for the lower quality lots. Field studies were conducted in two locations in upstate New York. The plant stand was greater in the high compared to the lower quality lots in both varieties at both locations. Yield was reduced in the lower quality than high quality lot; however, the response differed by variety and location. Overall, the initial seed quality had an impact on seed storagability, stand establishment and yield.

Free access

Abstract

Coal conversion technologies are emerging as alternative energy processes to complement traditional sources of petroleum and natural gas. The viability of the conversion technologies is a consequence of a number of factors, including the massive reserves of coal within our national boundaries, documented success in developing the various process technologies, existing systems for product distribution, and a diverse array of end products ranging from gas and liquid fuels to chemical feedstocks (18, 23). Coal conversion facilities are proposed throughout most regions of the continent, unlike many emerging energy technologies that have a limited distribution in North America (e.g., geothermal, oil shale and solar).

Open Access
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Abstract

There is considerable confusion in the literature regarding tomato fruit abnormalities variously termed “internal browning”, “gray wall”, “blotchy ripening”, and other less common terms such as “cloud” and “waxy patch”. It is difficult to determine if these names refer to one or more disorders because of the similarity of symptoms in ripening fruit. Tobacco mosaic virus (TMV) has been shown to play an important role in the occurrence of various fruit symptoms (2, 3, 4), yet this factor frequently is not considered in dealing with ripening disorders (1,5,6).

Open Access
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Field studies were. conducted in 1992 and 1993 to evaluate vacuum planters with respect to precision placement of seeds and to separately study plant spacing and emergence uniformity on stand establishment and yield. All studies were. performed with Bush Blue Lake 47. In 1992, a cooperative study was conducted with the Experiment Station and ten growers in Upstate New York representing four makes of commercial planters. No planter was able to precision seed, and seedling emergence revealed a large tendency to clump plant, with less errors made in the form of misses or skips. In 1993, tractor planting speed was studied as a variable from 3.4 to 12.3 KPH (2.1 to 7.6 MPH) on spacing uniformity and yield. The average number of seedlings per meter of row was similar for all treatments, however, the variation in spacing between plants generally increased as planter speed increased. In research plots, in-rowspacing and emergence uniformity were studied. Plant population was held constant and three in-row spacings were. developed (1 plant 5 cm apart, 2 plants 10 cm apart or 3 plants 15 cm apart). There were. no differences in yield in this study. Daily emergence was recorded and seedlings were grouped into three categories based on their time to emergence (early, medium or late). Yield was more than twice as much from early than late emerging seedlings, while the medium group was intermediate with respect to yield.

Free access

The seedcoat permeability, uptake, and transport of model fluorescent tracers were investigated in snapbean (Phaseolus vulgaris), pepper (Capsicum annuum), tomato (Solanum lycopersicum), onion (Allium cepa), cucumber (Cucumis sativus), and lettuce (Lactuca sativa) seeds. Nine fluorescent tracers and one vital stain were selected to represent a diversity of physicochemical properties (lipophilicity, electrical charge, etc.) and to simulate behavior of applied seed treatments. To study seedcoat permeability, tracers were applied to seeds as dry powders, and treated seeds were sown in moistened sand at 20 °C and removed after 18 to 24 h, a time before visible germination. Imbibed seeds were dissected and fluorescence (staining) was observed in embryos with a dissecting microscope under ultraviolet (365 nm) or visible radiation. Seedcoat permeability of species to solutes was grouped into three categories: 1) permeable—snapbeans; 2) selectively permeable—tomato, pepper, and onion; and 3) non-permeable—cucumber and lettuce. Systemic tracers that failed to permeate seedcoats during seed imbibition were taken up by roots or hypocotyls after visible germination.

Free access
Authors: and

Abstract

Deterioration of snap bean (Phaseolus vulgaris L.) seed quality during accelerated aging at 42°C and 100% relative humidity was accompanied by a decline in germination, radicle emergence, hypocotyl length, and ethylene production. Field emergence of 5 seed lots had a highly significant correlation with ethylene production rates when measured after 22 to 23.5 hours of imbibition at 25°. Seed lots that produced low levels of ethylene emerged poorly in the field. Results indicate that determination of ethylene production of imbibed seeds might be a useful method for detecting changes in seed vigor.

Open Access

Abstract

The objective of this study was to determine the relationship between seed density and seed quality of vegetable seeds hydrated by imbibing or priming procedures. Species studied were: lettuce (Lactuca sativa L.), tomato (Lycopersicon esculentum Mill.), onion (Allium cepa L.), cabbage (Brassica oleracea var. capitata L.), and carrot (Daucus carota L.). Seeds of each crop were soaked in either aerated distilled water at 25C (imbibed seeds) or polyethylene glycol (PEG) 8000 at 15C (primed seeds). After soaking, seeds were separated into density classes with a float-sink procedure using aqueous solutions of Maltrin 600 (Maltrin 500 for lettuce) with 0.02 g·cm−3 density increments. Significant (P > 0.01) positive relationships were determined between seed density classes and germination percentages for lettuce, tomato, and onion seeds, whether separated after imbibition (R 2 = 0.93, 0.83, and 0.66, respectively) or after priming (R 2 = 0.95, 0.94, and 0.91, respectively). High-density classes of hydrated lettuce, tomato, and onion seeds in either the imbibed or primed treatment usually exhibited faster and more uniform rates of radicle emergence and, after 6 days, had longer hypocotyls (cotyledon for onions) than low-density classes. The significant quality differences exhibited among the density classes of lettuce, tomato, and onion seeds after priming will enable seedlots of these species to be upgraded by discarding the low-density, poor-quality seeds.

Open Access

Biological seed treatments provides an alternative to chemical seed treatments or may also be used in combination with chemicals for effective control of plant pathogens. Seed treatment technologies are an important component of pest management, especially for effective biological control. Several seed treatments have been developed and evaluated to increase efficacy of the bioprotectant, Trichoderma harzianum, including 1) suspending the bioprotectant in a binder for a slurry application, 2) use of film coating technology, termed liquid coating, 3) combination of physiological treatments such as priming with the biological and 4) a dry planter box formulation. A laboratory bioassay consisting of sowing cucumber seeds in Pythium or other pathogen infested soil has shown that seed treatment technologies can enhance the efficacy of the bioprotectant. Field research has been conducted over four growing seasons on standard sugary and sh2 sweet corn. In general, emergence from seeds treated with Trichoderma by the described methods was comparable to seeds treated with chemical pesticides. Furthermore, plant growth was enhanced in several field studies.

Free access