California Agriculture, October 1971
Volume 25, Number 10
Biological control of California oakmoth with Bacillus thuringiensis
by Dudley E. Pinnock , James E. Milstead
BACILLUS THURINGIENSIS preparations proved to be highly effective for oakmoth control during field trials conducted in three areas of differing climate in northern California. The Bacillus thuringiensis preparations tested were Biotrol Dustable BTB 183 2.5D, Biotrol Wettable BTB 183 25 W, and Thuricide 90 TS 950-T. They were found to be equally effective for oakmoth control, though they differed in persistence of viable spores. Three types of equipment were used to apply the sprayable preparations, and all produced effective coverage but showed marked differences in wastage of material. Only one type of equipment was available for applying the dustable preparation. Application was timed to coincide with the early third instar of the oakmoth larvae, when a change in feeding behavior increased their exposure to the Bacillus thuringiensis. All three preparations were apparently fully compatible with the equipment for application, and no handling or disposal difficulties were encountered. The numbers of insect predators of oakmoth larvae were apparently unchanged by the Bacillus thuringiensis treatments and no phytotoxicity was noticed.
Improvements in fiber yield and quality… may come from test tube cotton
by C. A. Beasley , Irwin P. Ting , Leslie Ann Feigen
Abstract Not Available – First paragraph follows: TO KEEP UP WITH the continuously changing conditions under which they operate, farmers need some way to examine and to evaluate the alternative uses for their land. For example, thousands of acres now used for dryland crops can be developed for irrigation. But will it pay to do it? This study was made to evaluate the alternative agricultural uses for land now being used for dryIand farming. The study was based on an area in Tehama County where irinferior growth of fibers and ovules, as compared with the liquid medium.
Alternatives to dryland farming: …other crops, and irrigation, may-or may not-be worth the change
by Leland S. Frey
Going to the expense of shifting a parcel of land from dryland farming to the production of irrigated crops may—or may not be—profitable. In this study six alternative uses were compared for six parcels of land that were the same in every way except size. For ladino seed, canning olives, and irrigated pasture used either for growing out dairy heifers or the production of Grade A milk, the opportunity for profit improved as the size of the operation increased. On the other hand shifting from dry land barley to irrigated grain sorghum made a bad situation worse.
Diethylstilbestrol implant effects on suckling calves
by Monte Bell , Charles B. Wilson
Implanting suckling steer calves with 12 mg pellets of diethylstilbestrol (DES) resulted in weight gains of 22 lbs more by weaning time, and 42 lbs more by the end of the feedlot period, as compared with the controls. During marking and branding, 34 head of 114-day-old suckling steer calves were randomly assigned to either an implant, or control group. After weaning at 262 days of age, implanted and control cattle were fed for slaughter with all calves receiving 10 mg DES per day in the feed. The carcass weights and carcass weight-per-day-of-age of the implants (691 lbs and 1.43 lbs) were significantly greater (P <.001 and P <.05) than the controls (649 lbs and 1.34 lbs). Carcass measures and grades were similar for both groups except the implants had significantly (P <.01) more pounds of retail cuts per day of age than the controls (.68 vs. 65).
Preplant fumigation for sugar beet nematode on cabbage
by J. D. Radewald , B. J. Hall , F. Shibuya , J. Nelson
Preplant fumigation with 1,3-dichloropropene and related chlorinated C3 hydrocarbons and Agel TG-67 significantly increased cabbage yields over the untreated check where the nematode Heterodera schachtii was present in high numbers. Some weed control was also obtained with the Agel formulation. The high nematode populations present in the soils in the fumigated plots at the end of the growing season showed the need for rotation or annual fumigation if a susceptible crop is to be grown on infested land.
editorial, news, letters & science briefs
The grower's role
by Kenneth F. Baker