California Agriculture, November-December 1980
Volume 34, Number 11
peer-reviewed research articles
Management decisions can reduce blanking in rice
by James E. Board , Maurice L. Peterson
Early maturing, short-stature varieties; careful water management, and moderate use of nitrogen reduce excessive blanking.Rice growers can reduce losses to blanking with early-maturing, short-stature varieties; careful water management, and limited use of nitrogen fertilizer.
Blackline of English walnut trees traced to graft-transmitted virus
by S. M. John Mircetich , James Refsguard , Michael E. Matheron
Studies show that blackline can be spread from diseased to healthy trees by budding or grafting as well as by natural means.Blackline disease of walnut trees was experimentally graft-transmitted from infected to healthy trees. Causal agent: a strain of cherry leafroll virus.
Pyrethroid resistance persists in spider mite predator
by Marjorie A. Hoy , Nancy F. Knop , John L. Joos
Spider mite predators laboratory-selected for pyrethroid resistance successfully overwintered in a northern California apple orchard.A laboratory strain of spider mite predator resistant to low rates of pyrethroids became established and successfully overwintered in a northern California apple orchard.
Bioconversion: Tilapia fish turn insects and weeds into edible protein
by E. Fred Legner , Frank W. Pelsue
Feeding voraciously on chironomid midges or on aquatic weeds, two Tilapia fish species in southern California convert these nuisance pests into tons of edible fish protein.
Testing chrysanthemums for disease resistance
by Thomas G. Byrne , Arthur H. McCain , Thomas M. Kretchun
Chrysanthemum cultivars were evaluated for resistance to Verticillium wilt and black rust.
Oroblanco: A new grapefruit hybrid
by Robert K. Soost , James W. Cameron
An early-maturing cross of primmelo and grapefruit, Oroblanco has been released for use in interior citrus areas. It may be suitable for other intermediate climate zones.
Snail against snail
by Theodore W. Fisher , Robert E. Orth , Stuart C. Swanson
The decollate snail feeds on brown garden snail without harming healthy plants or fruit.Decollate snail attacks and eats brown garden snails but does not harm healthy plants.
California red scale predator may create citricola control dilemma
by Harold S. Elmer , O. L. Brawner , William H. Ewart
Citricola scale, now held in check by chemical controls for California red scale, could again become a major Central Valley citrus pest if a red scale predator is established.
Economic evaluation of mosquito control programs
by Mohammed E. Sarhan , Richard E. Howitt , Charles V. Moore , Carl J. Mitchell
Studies with statistical models show source reduction to be more economically efficient than chemical controls.Economic models suggest that, at least in one mosquito abatement district, measures to reduce sources would be more economically efficient than extensive use of pesticides.
Tomatoes make efficient use of applied nitrogen
by Francis E. Broadbent , Kent B. Tyler , Donald M. May
Although tomatoes are not as dependent on added nitrogen as other crops are, tests with labeled N show that they do make efficient use of nitrogen fertiher applications.
Larger sprinkler nozzles can save energy
by Blaine R. Hanson , Herbert Schulbach , Carl W. Rimbey , Kent Kaita
Increasing nozzle diameter can save a considerable amount of energy by reducing pump operating time, if adequate pressure can be maintained.Significant pumping energy savings may be realized by increasing sprinkler nozzle diameters to reduce pump operating time.
Delayed grazing may improve upland waterfowl habitat
by George B. Ruyle , John W. Menke , Donald L. Lancaster
Delaying cattle grazing until mid-July in wetlands and surrounding uplands of Modoc National Forest helped preserve vegetation needed by migratory waterfowl for nesting.
editorial, news, letters & science briefs
Grist for the mill
by J. B. Kendrick