Preliminary Evaluation of Production Systems and Forages for Culture of Orconectes virilis, the Northern or Fantail Crayfish

1990 ◽  
Vol 21 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Paul B. Brown ◽  
Michael L. Hooe ◽  
William G. Blythe
Keyword(s):  
Production Systems ◽  
Preliminary Evaluation ◽  
Orconectes Virilis

scholarly journals Agroecological zones and the assessment of crop production potential

1997 ◽  
Vol 352 (1356) ◽  
pp. 907-916 ◽  
Author(s):  
M. V. K. Sivakumar ◽  
C. Valentin
Keyword(s):  
Natural Resources ◽  
Crop Production ◽  
Production Systems ◽  
Agricultural Research ◽  
Development Planning ◽  
Weather Data ◽  
World Population ◽  
Preliminary Evaluation ◽  
Production Potential ◽  
Biological Potential

The rapidly growing world population puts considerable pressure on the scarce natural resources, and there is an urgent need to develop more efficient and sustainable agricultural production systems to feed the growing population. This should be based on an initial assessment of the physical and biological potential of natural resources, which can vary greatly. The agroecological zonation (AEZ) approach presents a useful preliminary evaluation of this potential, and ensures that representation is maintained at an appropriate biogeographic scale for regional sustainable development planning. The principal AEZs of the world, as described by the Technical Advisory Committee of the Consultative Group on International Agricultural Research, are presented along with their extent and characteristics. Net primary productivity of terrestrial vegetation can be assessed from weather data, and it varies from 1 t dry matter ha −1 yr −1 in high latitude zones and dry regions to 29 t ha −1 yr −1 in tropical wet regions, depending on the climatic conditions. To assess the crop production potential, length of the growing period zones, a concept introduced by the UN Food and Agriculture Organization, is very useful as it describes an area within which rainfall and temperature conditions are suitable for crop growth for a given number of days in the year. These data, combined with the information on soils and known requirements of different food crops, can be used to assess the potential crop productivity. Some perspectives on AEZs and crop production potential are presented by describing the manner in which production potential can be integrated with present constraints. Efforts to intensify production should place emphasis on methods appropriate to the socio-economic conditions in a given AEZ, and on promotion of conservation-effective and sustainable production systems to meet the food, fodder and fuel needs for the future.

scholarly journals Minimal Input Production Systems Affect Yield and Juice Quality of 'Sunbelt' Grapes in California's San Joaquin Valley

HortScience ◽  
2002 ◽  
Vol 37 (6) ◽  
pp. 867-870
Author(s):  
R. Keith Striegler ◽  
Chris B. Lake ◽  
Justin R. Morris ◽  
Renee T. Threlfall ◽  
Gary L. Main ◽  
...  
Keyword(s):  
Sensory Analysis ◽  
Production Systems ◽  
Climatic Conditions ◽  
San Joaquin Valley ◽  
Soluble Solids ◽  
Preliminary Evaluation ◽  
Juice Quality ◽  
Growing Seasons ◽  
High Yields

'Sunbelt' is a juice grape cultivar developed by the Univ. of Arkansas. This cultivar produces 'Concord'-type juice and is adapted to warm climatic conditions of the southern United States. Preliminary evaluation showed that 'Sunbelt' has potential to produce high-quality juice under the hot climatic conditions of the San Joaquin Valley. A study was conducted during the 1998 and 1999 growing seasons to further evaluate the adaptation of 'Sunbelt' to the San Joaquin Valley and determine the response of this cultivar to selected pruning methods. Vines were grown for two seasons without use of insecticides, fungicides, or herbicides. Vines were subjected to four pruning treatments: severe hand pruning (60-80 nodes retained/vine); moderate hand pruning (120-160 nodes retained/vine); machine pruning with hand follow-up (160-180 nodes retained/vine); and minimal pruning (200-400 nodes retained/vine). Vines were trained to a Geneva Double Curtain trellis system. Yield, components of yield, and juice quality were significantly impacted by pruning treatment. In both seasons, mechanized systems of pruning (machine and minimal) produced higher yield than hand pruning. Minimal pruning resulted in the highest yield (42 t·ha-1) in 1998, while yield from the machine-pruned vines was highest (29 t·ha-1) in 1999. Minimally pruned vines had the highest clusters/vine and lowest cluster weight among the treatments. The extremely high yields obtained for the minimal pruning treatments produced fruit that was less mature resulting in juice with lower soluble solids than the other treatments in 1998. However, in 1999 the juice from minimally pruned vines had the highest soluble solids. Sensory analysis of juice produced in 1999 showed that the juice from the machine-pruned treatment had the least color intensity. Sensory analysis showed that minimal and severe hand pruning were ranked higher for sweetness than machine and moderate hand pruning. In the second year of the study, the juice from the minimal-pruned and severe hand-pruned treatment were preferred over the moderate hand-pruned treatment or the machine-pruned treatment.

scholarly journals Preliminary evaluation of associated viruses in production systems of cape gooseberry, purple passion fruit, and rose

2018 ◽  
Vol 12 (2) ◽  
pp. 390-396 ◽  
Author(s):  
Joseph Cutler ◽  
Juliane Langer ◽  
Susanne Von Bargen ◽  
Orlando Acosta-Losada ◽  
Fánor Casierra-Posada ◽  
...  
Keyword(s):  
Field Study ◽  
Plant Virus ◽  
Production Systems ◽  
Monitoring Program ◽  
Plant Viruses ◽  
Diagnostic Methods ◽  
Passion Fruit ◽  
Preliminary Evaluation ◽  
Purple Passion Fruit ◽  
Cape Gooseberry

Plant viruses may pose a threat to crops in Colombia. To evaluate the potential risk of yield losses due to plant virus infection, a literature analysis followed by a first field study was carried out focusing on purple passion fruit (Passiflora edulis Sims), cape gooseberry (Physalis peruviana L.), and ornamental rose (Rosa sp.), which are important Colombian exports. Over the past three years, plant material was collected from 21 farms in Cundinamarca and Boyacá, Colombia, two regions that are in close proximity to El Dorado International Airport, the country’s largest air freight terminal. Plants were visually inspected and subsequently tested by bioassay and serological methods. Overall, in the samples investigated by the two diagnostic methods, plant viruses were detected. Detected viruses belong to the genus Poty-, Tobamo-, Nepo-, Ilar-, and Tospovirus. The extent of the distribution and occurrence of these viruses in each crop has to be determined in a representative field study. Such a monitoring program could be supported by a standardized farmer interview. The development of suitable plant virus diagnostic and managements tools is the focus of a cooperation project between German and Colombian universities, the Colombian Agricultural Institute (ICA), the Colombian Corporation of Agricultural Investigation (AGROSAVIA) and the International Center for Tropical Agriculture (CIAT).

scholarly journals 641 Preliminary Evaluation of Organic Desert Vegetable Production Systems

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 508A-508
Author(s):  
A. Galadima ◽  
C.A. Sanchez ◽  
J. Palumbo ◽  
B. Tickes ◽  
M. Matheron ◽  
...  
Keyword(s):  
Production Systems ◽  
N Uptake ◽  
Organic Production ◽  
Preliminary Evaluation ◽  
Vegetable Production ◽  
Labor Costs ◽  
Management Options ◽  
Strict Adherence ◽  
Organic Systems ◽  
Yield And Quality

Experiments were conducted during 1998–99 seasons to evaluate the potential for organic vegetable production in the low desert of the southwestern United States. The experimental design included three summer management options [fallow, cowpea (Vigna sinensis), and sudangrass (Sorghum vulgare)] in factorial combination with alternative production systems, which included organic and conventional systems. The crops cultivated were iceberg lettuce (Lactuca sativa L) during the fall–winter period and melons (Cucumis melo Reticulatus Group) during the spring. The organic plots were managed with strict adherence to California Certified Organic Farmers (CCOF) guidelines. Summer cover crop management seemed to influence the early growth and N uptake of lettuce, but had no final effect on yield and quality. The organic production system resulted in lower yields and inferior product quality compared to the conventional system. Generally, disease and weeds were not limiting factors, although labor costs for weed control would be slightly higher in organic plots. Insects, primarily aphids (various types) and thrips (Frankliniella Occidentalis Perancle), and fertility, primarily N, were factors limiting yield and quality in organic systems. Control of whiteflies (Bemisia argentifoli) was the limiting factor for melons. Studies during 1999–2000 are focused on overcoming the challenges of the insect and fertility management in organic systems.

Preliminary Evaluation of a Weibull Function for Fitting Slow-Component Eye Velocity over the Time Course of Caloric-Induced Nystagmus

1989 ◽  
Vol 32 (3) ◽  
pp. 681-687 ◽  
Author(s):  
C. Formby ◽  
B. Albritton ◽  
I. M. Rivera
Keyword(s):  
Time Course ◽  
Slow Component ◽  
Weibull Function ◽  
Preliminary Evaluation ◽  
Mathematical Function ◽  
Before And After ◽  
Best Fitting ◽  
Eye Velocity ◽  
Fitting Parameters ◽  
Weibull Equation

We describe preliminary attempts to fit a mathematical function to the slow-component eye velocity (SCV) over the time course of caloric-induced nystagmus. Initially, we consider a Weibull equation with three parameters. These parameters are estimated by a least-squares procedure to fit digitized SCV data. We present examples of SCV data and fitted curves to show how adjustments in the parameters of the model affect the fitted curve. The best fitting parameters are presented for curves fit to 120 warm caloric responses. The fitting parameters and the efficacy of the fitted curves are compared before and after the SCV data were smoothed to reduce response variability. We also consider a more flexible four-parameter Weibull equation that, for 98% of the smoothed caloric responses, yields fits that describe the data more precisely than a line through the mean. Finally, we consider advantages and problems in fitting the Weibull function to caloric data.

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