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Calag Archive

Calag Archive

November 1977
Volume 31, Number 11

Peer-reviewed research and review articles

Pheromone traps to suppress populations of the smaller European elm bark beetle
by Martin C. Birch, Richard W. Bushing, Timothy D. Paine, Stephen L. Clement, P. Dean Smith
| Full text HTML  | PDF  
Field studies to evaluate the possibility of trapping beetles before they spread Dutch elm disease found that elm woodpiles appear to be a major source of beetles, and that beetles may disperse far greater distances than previously thought.
Dutch elm disease (DED) has devastated elm populations throughout large portions of the eastern and midwestern United States. This disease has gradually spread westward since its accidental introduction from Europe into North America in 1930. First discovered in California in Sonoma County in August, 1975, DED is a threat to elm populations throughout the state. The California Department of Food and Agriculture is committed to exploring the feasibility of eradicating the disease before it spreads from its initial infection sites.
Damping-off in cotton controlled with combination seed treatment fungicides
by Albert O. Paulus, Jerry Nelson, Otis Harvey, F. Shibuya
| Full text HTML  | PDF  
Combination cotton seed treatments controlling both Rhizoctonia and Pythium were consistently better than single seed treatments.
Damping-off of cotton seedlings in southern California is caused by two fungi, Rhizoctonia solani and Pythium spp. Seed rot and seedling decline are particularly severe during cool, wet weather and when soil temperatures are below 60° F. Several new fungicides were tested against common, standard, commercial fungicides.
Barley, wheat, and triticale responses to planting date and seeding rate
by Y. Paul Puri, Calvin O. Qualset, Kenneth G. Baghott
| Full text HTML  | PDF  
In studies conducted at Tulelake Field Station, wheat and triticale yields were reduced by 70 pounds per day for each day that planting was delayed after April 16. Barley was less sensitive to delayed planting. Variation in seeding rate had less dramatic effect on grain yields.
Yield potential of a crop is dependent upon genetic and environmental factors. The environmental factors can be manipulated to exploit the maximum yield potential of a variety. As new varieties are developed or introduced into an area, new and efficient cultural practices must be developed. This study at Tulelake was conducted under irrigation to determine the effects of planting dates and seeding rates on the yield and other agronomic characteristics of wheat, barley and triticale.
Diagnostic service identifies insect pathogens
by Gerard M. Thomas, George O. Poinar
| Full text HTML  | PDF  
The Service offers formal laboratory diagnosis of insect diseases and advises in their control. It also discovers new pathogens which may be used as biological control agents, and maintains a reference collection of insect pathogenic microorganisms.
The Department of Entomological Sciences at the University of California in Berkeley offers the only diagnostic service in the United States with equipment and experienced personnel for formal laboratory diagnosis of insect diseases. The Diagnostic Service, started in Berkeley by Edward A. Steinhaus in 1944 as an aid to university entomologists, rapidly grew into a worldwide service. The Service was run by Professor Steinhaus and Gordon A. Marsh until 1964, and has been run by the present authors since then (fig. 1).
Projection of California fertilizer use to 1985
by Hoy F. Carman, Cris Heaton
| Full text HTML  | PDF  
Projections to 1985 for fertilizer sales in California (which have tripled for nitrogen and potash and more than doubled for phosphate since 1955) foresee an increase for all three nutrients of 17.59 percent over sales reported in 1973.
California commercial fertilizer sales have grown dramatically since 1955. Total sales of nitrogen (N) and potash (K) tripled while phosphate (P) sales more than doubled. Total fertilizer sales of 830,000 tons for the year ending June 30,1976 were distributed approximately 71 percent nitrogen, 22 percent phosphates, and 7 percent potash. The highly diversified and intensive cropping patterns characteristic of California agriculture will continue to require large amounts of fertilizer to maintain present levels of production.
Post-harvest codling moth infestion on pears—a potential threat for next year's crop
by Helmut Riedl, James E. DeTar
| Full text HTML  | PDF  
Unexpectedly large overwintering populations may result from infestations on unpicked fruit. Codling moth build-up during the post-harvest period can be predicted reliably from seasonal pheromone trap catches.
Rauschkolb and Mikkelsen (“Survey of Fertilizer Use in California- 1973,” UC Division of Agricultural Sciences bulletin, forthcoming) estimated common fertilizer application rates and percentages of land fertilized by area for individual crops in 1973. We derived weighted statewide application rates from these estimates. Thus, our estimates of application rates are based on the cropping pattern existing in 1973. A significant change in the location of crop production in California could produce a substantial change in fertilizer use without any change in fertilizer prices or planted acreage.
Sunflower resistance to the sunflower moth
by Benjamin H. Beard, Elmer C. Carlson, Anthony C. Waiss, Carl Elliger, John M. Klislewfcz, Alan Johnson, Bock Chan
| Full text HTML  | PDF  
Development of sunflower varieties or hybrids resistant to the seed-destroying larvae of the sunflower moth seems promising, but efforts have been stymied by erratic populations of moths in the field and difficulty in rearing moths for artificial testing for resistance.
The sunflower moth (Homoeosoma electellum Hulst.) will probably never be put on the endangered species list, but many California farmers would iike to see it as extinct as the dinosaurs because of the damage it does to the sunflower crop. This pest has also caused extensive damage to sunflower in Georgia, Kansas, Louisiana, Missouri, Nebraska, Texas, Minnesota, North Dakota, and in parts of Canada
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November 1977
Volume 31, Number 11

Peer-reviewed research and review articles

Pheromone traps to suppress populations of the smaller European elm bark beetle
by Martin C. Birch, Richard W. Bushing, Timothy D. Paine, Stephen L. Clement, P. Dean Smith
| Full text HTML  | PDF  
Field studies to evaluate the possibility of trapping beetles before they spread Dutch elm disease found that elm woodpiles appear to be a major source of beetles, and that beetles may disperse far greater distances than previously thought.
Dutch elm disease (DED) has devastated elm populations throughout large portions of the eastern and midwestern United States. This disease has gradually spread westward since its accidental introduction from Europe into North America in 1930. First discovered in California in Sonoma County in August, 1975, DED is a threat to elm populations throughout the state. The California Department of Food and Agriculture is committed to exploring the feasibility of eradicating the disease before it spreads from its initial infection sites.
Damping-off in cotton controlled with combination seed treatment fungicides
by Albert O. Paulus, Jerry Nelson, Otis Harvey, F. Shibuya
| Full text HTML  | PDF  
Combination cotton seed treatments controlling both Rhizoctonia and Pythium were consistently better than single seed treatments.
Damping-off of cotton seedlings in southern California is caused by two fungi, Rhizoctonia solani and Pythium spp. Seed rot and seedling decline are particularly severe during cool, wet weather and when soil temperatures are below 60° F. Several new fungicides were tested against common, standard, commercial fungicides.
Barley, wheat, and triticale responses to planting date and seeding rate
by Y. Paul Puri, Calvin O. Qualset, Kenneth G. Baghott
| Full text HTML  | PDF  
In studies conducted at Tulelake Field Station, wheat and triticale yields were reduced by 70 pounds per day for each day that planting was delayed after April 16. Barley was less sensitive to delayed planting. Variation in seeding rate had less dramatic effect on grain yields.
Yield potential of a crop is dependent upon genetic and environmental factors. The environmental factors can be manipulated to exploit the maximum yield potential of a variety. As new varieties are developed or introduced into an area, new and efficient cultural practices must be developed. This study at Tulelake was conducted under irrigation to determine the effects of planting dates and seeding rates on the yield and other agronomic characteristics of wheat, barley and triticale.
Diagnostic service identifies insect pathogens
by Gerard M. Thomas, George O. Poinar
| Full text HTML  | PDF  
The Service offers formal laboratory diagnosis of insect diseases and advises in their control. It also discovers new pathogens which may be used as biological control agents, and maintains a reference collection of insect pathogenic microorganisms.
The Department of Entomological Sciences at the University of California in Berkeley offers the only diagnostic service in the United States with equipment and experienced personnel for formal laboratory diagnosis of insect diseases. The Diagnostic Service, started in Berkeley by Edward A. Steinhaus in 1944 as an aid to university entomologists, rapidly grew into a worldwide service. The Service was run by Professor Steinhaus and Gordon A. Marsh until 1964, and has been run by the present authors since then (fig. 1).
Projection of California fertilizer use to 1985
by Hoy F. Carman, Cris Heaton
| Full text HTML  | PDF  
Projections to 1985 for fertilizer sales in California (which have tripled for nitrogen and potash and more than doubled for phosphate since 1955) foresee an increase for all three nutrients of 17.59 percent over sales reported in 1973.
California commercial fertilizer sales have grown dramatically since 1955. Total sales of nitrogen (N) and potash (K) tripled while phosphate (P) sales more than doubled. Total fertilizer sales of 830,000 tons for the year ending June 30,1976 were distributed approximately 71 percent nitrogen, 22 percent phosphates, and 7 percent potash. The highly diversified and intensive cropping patterns characteristic of California agriculture will continue to require large amounts of fertilizer to maintain present levels of production.
Post-harvest codling moth infestion on pears—a potential threat for next year's crop
by Helmut Riedl, James E. DeTar
| Full text HTML  | PDF  
Unexpectedly large overwintering populations may result from infestations on unpicked fruit. Codling moth build-up during the post-harvest period can be predicted reliably from seasonal pheromone trap catches.
Rauschkolb and Mikkelsen (“Survey of Fertilizer Use in California- 1973,” UC Division of Agricultural Sciences bulletin, forthcoming) estimated common fertilizer application rates and percentages of land fertilized by area for individual crops in 1973. We derived weighted statewide application rates from these estimates. Thus, our estimates of application rates are based on the cropping pattern existing in 1973. A significant change in the location of crop production in California could produce a substantial change in fertilizer use without any change in fertilizer prices or planted acreage.
Sunflower resistance to the sunflower moth
by Benjamin H. Beard, Elmer C. Carlson, Anthony C. Waiss, Carl Elliger, John M. Klislewfcz, Alan Johnson, Bock Chan
| Full text HTML  | PDF  
Development of sunflower varieties or hybrids resistant to the seed-destroying larvae of the sunflower moth seems promising, but efforts have been stymied by erratic populations of moths in the field and difficulty in rearing moths for artificial testing for resistance.
The sunflower moth (Homoeosoma electellum Hulst.) will probably never be put on the endangered species list, but many California farmers would iike to see it as extinct as the dinosaurs because of the damage it does to the sunflower crop. This pest has also caused extensive damage to sunflower in Georgia, Kansas, Louisiana, Missouri, Nebraska, Texas, Minnesota, North Dakota, and in parts of Canada

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