California Agriculture, September 1969
Volume 23, Number 9
The scanning electron microscope offers new techniques for the diagramming diagnostic characters on insects
by E. F. Legner , M. Kogan
The remarkable high resolution, and three-dimensional clarity of the new scanning electron microscopes are giving researchers their first accurate view of many minute insect parts—an advance comparable with the change from a magnifying glass to a conventional microscope.
Triticale… problems and progress with a new cereal crop
by C. O. Qualset , W. H. Isom , J. D. Prato , Y. P. Puri , G. F. Worker
Abstract Not Available – First paragraph follows: TRITICALE IS A SYNTHETIC CEREAL species—a product of man's ingenuity and his ability to manipulate delicately balanced biological systems. Specialized techniques used in creating this new species include doubling the chromosome number and culturing immature embryos artificially. Triticales, resulting from hybridizing wheat (Triticum) and rye (Secede), are technically called am-phiploids. The hybrid is not new; in fact, wheat-rye hybrids were first reported in the nineteenth century. In the past 30 years, many triticales have been produced, from both common wheats (42 chromosomes) and durum wheats (28 chromosomes) in crosses with rye (14 chromosomes). The bread wheat-rye triticales (octoploids) were studied extensively but did not combine desirable qualities of the two parents as anticipated. Similarly, durum wheat-rye triticales (hexaploids) did not meet expectations. Major defects of triticales included wrinkled grain, sterility in the spikes, low grain yield, poor baking and milling quality, and late maturity. The poorer qualities of both wheat and rye appeared to be combined in triticale. The stage was set, however, for major improvement when hexaploid and octoploid triticales, obtained from plant breeders throughout the world, were observed and intercrossed at the University of Manitoba from 1954 to 1962. These new crosses, among triticales themselves, produced agronomically promising types. The new types from Manitoba have stimulated interest in triticale research.
Cubed alfalfa for replacement ewe lambs
by Monte Bell , Jack Nolan , Albert Vieria
In this trial, alfalfa hay cubes self fed to white face and Hampshire ewe lambs resulted in small but statistically significant increases in weight gains, along with increased feed consumption but with less waste feed than when comparable ewes were fed baled alfalfa hay daily. Suffolk ewe lambs gained equally well on either cubes or baled hay.
Weed control in young grapes
by A. H. Lange , B. Fischer , H. Agamalian , H. Kempen
Under the conditions of the experiments reported, trifluralin, nitralin, DCPA, bensulide and two commercially unavailable compounds were safest on young grape vines. Fair to good weed control was obtained at safe rates except where resistant weed species were present. Shallow incorporated trifluralin will control weeds at 1/2 to 1 lb per acre rates, and will prove useful for weed control in grape nurseries; however, care should be taken to follow the labeled rates and directions for incorporation. Combinations of the grass herbicides such as trifluralin, nitralin, DCPA, diphenamid and bensulide with simazine and several new herbicides for broadleaf weed control are being studied further.
Smog injury, root diseases and bark beetle damage in ponderosa pine
by R. W. Stark , F. W. Cobb
Photochemical oxidants (smog) are causing serious injury to ponderosa pine in the San Bernardino Mountains of southern California. Apparently, smog injury also renders the trees more susceptible to attack by two species of destructive forest insects, the western pine beetle, Dendroctonus brevicomis, and the mountain pine beetle, D. ponderosae. Recent studies have shown that photochemical oxidant injury to ponderosa pine results in reduced oleoresin yield, rate of flow and exudation pressure, sapwood and phloem moisture content and phloem thickness, all of which are believed important in the defense of the tree against bark beetles. Smog injury also affects growth rate and probably wood quality. Soluble sugars and reserve polysaccharides were reduced in diseased trees. Current studies indicate that similar injuries to ponderosa pine, with resulting increase in bark beetle attack, occur as a result of infection by root disease fungi, notably Fomes annosus and Verticicladiella wagenerii.
editorial, news, letters & science briefs
Research management decisions
by Mark T. Buchanan
Cockroach research University of California Los Angeles