California Agriculture
California Agriculture
California Agriculture
University of California
California Agriculture

Archive

California Agriculture, Vol. 56, No.4

UC responds to Klamath conundrum Also: Special focus on irrigation effiency
Cover:  From the Klamath Basin to the Rio Grande, water is a much-disputed commodity in California. Increasingly, agricultural users must compete with environmental and urban needs for scarce water supplies. In this issue of California Agriculture, news and research articles focus on how growers and other water users can irrigate more efficiently and effectively. The cover story explores how UC has responded to the water crisis in the Klamath Basin, where hundreds of growers did not receive irrigation water in 2001 due to a severe drought and concerns about protecting three endangered fish species. Through research and outreach, the University plays a critical role in ensuring that precious water is utilized to the best advantage for wildlife, crops, and people. Cover graphic by Davis Krauter
July-August 2002
Volume 56, Number 4

Peer-reviewed research and review articles

Improving pumping plant efficiency does not always save energy
by Blaine R. Hanson
| Full text HTML  | PDF  
Efficiency can be improved by adjusting impellers, repairing worn pumps, replacing mismatched pumps or using energy-efficient motors.
California's energy crisis in 2001 resulted in a state-funded program for testing irrigation pumps and improving pumping plant efficiency, with the goal of reducing energy use in California agriculture. Yet in reality, improving pumping plant efficiency may not actually translate into savings. To reduce electrical energy use, the kilowatt-hours must decrease because of fewer kilowatts or less operating time, or both. In order to evaluate the efficiency of various energy-improving adjustments, we studied several operations at pumping plants in the San Joaquin Valley. These included adjusting impellers, repairing worn pumps, replacing mismatched pumps and using more energy-efficient motors. We found that adjusting or repairing worn pumps may actually increase energy use, unless the operating time of the pumping plant is reduced. Multiple pump tests of a pumping plant are recommended, to help evaluate possible reasons for low efficiency. Pumping plant operators should also obtain the manufacturer's performance curves to use in the evaluation process.
Garlic in clay loam soil thrives on little irrigation
by Blaine R. Hanson, Don May, Ronald Voss, Marita Cantwell, Robert Rice
| Full text HTML  | PDF  
Four years of irrigation experiments help determine frequency, cutoff dates and irrigation amounts for garlic grown in sandy and clay loam soil.
We conducted 4 years of irrigation experiments in garlic on the West Side of the San Joaquin Valley to determine appropriate irrigation frequency and cutoff dates as well as the effect of irrigation on yields for crops grown in sandy and clay loam soil. In sandy soil with the moisture content at field capacity prior to the rapid growth stage, yield was strongly dependent on applied water, and weekly irrigation was needed for maximum yield. In clay loam, yield did not depend on applied water because the garlic plants were able to extract sufficient soil moisture to offset deficit irrigation. Irrigation cutoff in both soils should occur by mid-May.
Buried drip irrigation reduces fungal disease in pistachio orchards
by David A. Goldhamer, Themis J. Michailides, David P. Morgan
| Full text HTML  | PDF  
High humidity increases the severity of pistachio blight infections, reducing marketability; the type of irrigation system affects humidity levels.
Alternaria late blight, a fungal disease affecting both leaves and fruit, can lower the quality of pistachios and reduce grower profit. High humidity in orchards increases the magnitude and severity of the blight infections. One cause of high orchard humidity is the evaporation of water from the soil surface, which in turn is enhanced by irrigation systems that wet the surface. In this study, we tested the use of buried drip irrigation, which reduces orchard floor wetting, to see how well it controlled the disease. When compared with a traditional flood irrigation system, the buried drip system reduced orchard humidity and dew duration and increased temperature. This significantly reduced leaf symptoms of the disease and fruit infection at harvest. Additionally, more shells split open with the buried drip method, resulting in a higher yield of marketable pistachios.
Focus groups show need for diabetes awareness education among African Americans
by Estella A. West, Gloria R. Brown, Nancy I. Feldnian, Connie L. Garrett, Anna Martin, Anna Olivares, Edwina U. Williams, Christine M. Bruhn, Marciel A. Klenk
| Full text HTML  | PDF  
Although obesity is a major risk factor for type 2 diabetes, most participants considered poor dietary patterns a more important factor than body weight.
The UC Division of Agriculture and Natural Resources Health Promotion Workgroup assessed diabetes awareness among African Americans at risk for the disease. Workgroup members conducted focus group discussions with the target population in Los Angeles, San Bernardino, San Joaquin, San Mateo, Santa Clara and Stanislaus counties. Although obesity is considered a major risk factor for type 2 diabetes, most participants cited poor dietary patterns, rather than body weight, as the most important factor in the high rate of diabetes among African Americans. Food preferences, family pressure and lack of social support were most often mentioned as obstacles to healthful dietary changes. Many felt that not enough information about diabetes was reaching the black community and voiced the need for culturally sensitive education, delivered through community-based channels.
Webmaster Email: wsuckow@ucanr.edu

Thank you for visiting us at California Agriculture. We have created this printable page for you to easily view our website offline. You can visit this page again by pointing your Internet Browser to-

http://calag.ucanr.edu/archive/index.cfm?issue=56_4

California Agriculture, Vol. 56, No.4

UC responds to Klamath conundrum Also: Special focus on irrigation effiency
Cover:  From the Klamath Basin to the Rio Grande, water is a much-disputed commodity in California. Increasingly, agricultural users must compete with environmental and urban needs for scarce water supplies. In this issue of California Agriculture, news and research articles focus on how growers and other water users can irrigate more efficiently and effectively. The cover story explores how UC has responded to the water crisis in the Klamath Basin, where hundreds of growers did not receive irrigation water in 2001 due to a severe drought and concerns about protecting three endangered fish species. Through research and outreach, the University plays a critical role in ensuring that precious water is utilized to the best advantage for wildlife, crops, and people. Cover graphic by Davis Krauter
July-August 2002
Volume 56, Number 4

Peer-reviewed research and review articles

Improving pumping plant efficiency does not always save energy
by Blaine R. Hanson
| Full text HTML  | PDF  
Efficiency can be improved by adjusting impellers, repairing worn pumps, replacing mismatched pumps or using energy-efficient motors.
California's energy crisis in 2001 resulted in a state-funded program for testing irrigation pumps and improving pumping plant efficiency, with the goal of reducing energy use in California agriculture. Yet in reality, improving pumping plant efficiency may not actually translate into savings. To reduce electrical energy use, the kilowatt-hours must decrease because of fewer kilowatts or less operating time, or both. In order to evaluate the efficiency of various energy-improving adjustments, we studied several operations at pumping plants in the San Joaquin Valley. These included adjusting impellers, repairing worn pumps, replacing mismatched pumps and using more energy-efficient motors. We found that adjusting or repairing worn pumps may actually increase energy use, unless the operating time of the pumping plant is reduced. Multiple pump tests of a pumping plant are recommended, to help evaluate possible reasons for low efficiency. Pumping plant operators should also obtain the manufacturer's performance curves to use in the evaluation process.
Garlic in clay loam soil thrives on little irrigation
by Blaine R. Hanson, Don May, Ronald Voss, Marita Cantwell, Robert Rice
| Full text HTML  | PDF  
Four years of irrigation experiments help determine frequency, cutoff dates and irrigation amounts for garlic grown in sandy and clay loam soil.
We conducted 4 years of irrigation experiments in garlic on the West Side of the San Joaquin Valley to determine appropriate irrigation frequency and cutoff dates as well as the effect of irrigation on yields for crops grown in sandy and clay loam soil. In sandy soil with the moisture content at field capacity prior to the rapid growth stage, yield was strongly dependent on applied water, and weekly irrigation was needed for maximum yield. In clay loam, yield did not depend on applied water because the garlic plants were able to extract sufficient soil moisture to offset deficit irrigation. Irrigation cutoff in both soils should occur by mid-May.
Buried drip irrigation reduces fungal disease in pistachio orchards
by David A. Goldhamer, Themis J. Michailides, David P. Morgan
| Full text HTML  | PDF  
High humidity increases the severity of pistachio blight infections, reducing marketability; the type of irrigation system affects humidity levels.
Alternaria late blight, a fungal disease affecting both leaves and fruit, can lower the quality of pistachios and reduce grower profit. High humidity in orchards increases the magnitude and severity of the blight infections. One cause of high orchard humidity is the evaporation of water from the soil surface, which in turn is enhanced by irrigation systems that wet the surface. In this study, we tested the use of buried drip irrigation, which reduces orchard floor wetting, to see how well it controlled the disease. When compared with a traditional flood irrigation system, the buried drip system reduced orchard humidity and dew duration and increased temperature. This significantly reduced leaf symptoms of the disease and fruit infection at harvest. Additionally, more shells split open with the buried drip method, resulting in a higher yield of marketable pistachios.
Focus groups show need for diabetes awareness education among African Americans
by Estella A. West, Gloria R. Brown, Nancy I. Feldnian, Connie L. Garrett, Anna Martin, Anna Olivares, Edwina U. Williams, Christine M. Bruhn, Marciel A. Klenk
| Full text HTML  | PDF  
Although obesity is a major risk factor for type 2 diabetes, most participants considered poor dietary patterns a more important factor than body weight.
The UC Division of Agriculture and Natural Resources Health Promotion Workgroup assessed diabetes awareness among African Americans at risk for the disease. Workgroup members conducted focus group discussions with the target population in Los Angeles, San Bernardino, San Joaquin, San Mateo, Santa Clara and Stanislaus counties. Although obesity is considered a major risk factor for type 2 diabetes, most participants cited poor dietary patterns, rather than body weight, as the most important factor in the high rate of diabetes among African Americans. Food preferences, family pressure and lack of social support were most often mentioned as obstacles to healthful dietary changes. Many felt that not enough information about diabetes was reaching the black community and voiced the need for culturally sensitive education, delivered through community-based channels.

University of California, 1301 S. 46th St., Bldg. 478 Richmond, CA
Email: calag@ucanr.edu | Phone: (510) 665-2163 | Fax: (510) 665-3427
Please visit us again at http://californiaagriculture.ucanr.edu/