California Agriculture, May-June 1987
Volume 41, Number 5
peer-reviewed research articles
Control of stink bugs in tomatoes
by Michael P. Hoffmann , Lloyd T. Wilson , Frank G. Zalom
The southern green stink bug, new to California, has joined other species as a pest of processing tomatoes. With a wide host range, it is a potentially serious pest on other crops.Southern green stink bug, shown in cover photo by Jack Kelly Clark, was recently discovered in California and could become a serious pest of tomatoes and other crops because of its very wide host range. Chemical control of stink bugs is often ineffective, possibly because the bugs stay under the plant canopy, where sprays don't reach them.
Control of Oriental fruit moth by mating disruption
by Craig V. Weakley , Philipp Kirsch , Richard E. Rice
Confusing the male Oriental fruit moth by flooding peach orchards with the female's pheromone provided excellent control of the insect and may be an alternative to conventional insecticide use.Pheromone releases to disrupt mating controlled Oriental fruit moth damage to peaches and nectarines.
The California-Arizona lemon cycle continues
by Hoy F. Carman , Richard D. Green , William Kinney
Projections of the lemon cycle indicate that average total revenue per acre in 1998–99 will drop to the same level seen in 1984–85, if growers continue to respond as they have in the past.The swings in production and prices could be dampened by grower awareness of the patterns and long-term causes.
Fungicides for leafspot control on strawberry
by Marvin J. Snyder , Albert O. Paulus , Victor Voth , Jerry Nelson
Two currently registered fungicides controlled common leafspot. Other materials tested showed promise.
Manger misting improves dairy cows' appetite
by Thomas A. Shultz , Stanton R. Morrison
Misting also decreased losses in milk yield, reduced cow mortality after calving, and improved reproduction.Misting corral feed mangers during heat waves more than pays for itself in improved milk yield and reproduction.
Selenium enhances lamb gains on sulfur-fertilized pastures
by Milton B. Jones , D. Michael Center , Victor V. Rendig , Martin R. Dally , Ben B. Norman , William A. Williams
Large responses to sulfur can occur when nitrogen is applied to many California rangeland soils. Giving lambs selenium in pellet form significantly improved gain on such pastures.Sulfur fertilization increased forage and lamb gain, but selenium supplementation was needed for maximum gain.
Testing to predict tomato harvest worker performance
by Gregory Encina Billikopf
A study of a group of tomato pickers suggests that a work-sample test could be useful in choosing harvest workers.
Groundwater flows to the San Joaquin River
by Elias A. Rashmawi , Mark E. Grismer
Groundwater may represent only a fraction of one percent of the river's total annual flow.A preliminary model indicates that groundwater flow to the river is relatively small.
Correcting potassium deficiency in prune trees is profitable
by William H. Olson , Kiyoto Uriu , Robert M. Carlson , William H. Krueger , James Pearson
Even a slight deficiency can be costly. A single application of potash fertilizer can correct the deficiency for three to four years.Prune quality and value were highest in nondeficient trees, suggesting that potassium fertilization is profitable.
Resistance of the little house fly to insecticides on poultry facilities
by Jeffery A. Meyer , George P. Georghiou
The fly has developed surprisingly little resistance to the insecticides most commonly used to control it.Resistance was low at the four facilities tested, despite heavy use of insecticides on some.
editorial, news, letters & science briefs
The UC Agricultural Issues Center
by Lowell N. Lewis