In This Issue

Using Pheromone Traps to Monitor Pests of Stone Fruits

Pheromone traps can be successfully used to monitor pests in stone fruit orchards. When using these traps it is important to follow certain guidelines so that trapping data can be acccurately interpreted.

Because of variability between locations, it is important to place traps in each orchard for which projections are to be made. Pest emergence and treatment timing can be affected by many factors, and treatment recommendations should always be based on data from specific orchards.

In general, trap density for Oriental Fruit Moth (OFM), Peach Twig Borer (PTB) and Codling Moth (CM) should be at least two traps per orchard, and at least one trap for every 10 acres. Traps for San Jose Scale (SJS) should be placed at a density of at least 3 to 4 per orchard. If using double sided sticky tape to catch SJS crawlers place tape on at least 2-3 limbs in 5-10 trees per orchard.

Place traps on the north side of the tree at a height of 6-7 feet. To avoid border effects the traps should be placed at least ten tree spaces in from the edge of the orchard. If orchard history shows that pest problems are localized in certain parts of an orchard, it may be valuable to increase the trap density in that area. Traps should also be placed in the same general location from year to year so that between year comparisons can be made more accurately.

Orchard Frost Protection

As bloom approaches frost protection may be necessary in some orchard locations. The accompanying tables provide information for use in frost protection decision making.

Trapping Guidelines for the Major Pests of Peaches, Nectarines, And Plums

*Biofix - the first date that pests are consistently found in traps. Begin accumulating DD from this date.

Note: This is intended as a general guide only. For more detailed information refer to the UC IPM Guidelines available at local Cooperative Extension Offices.

Winter Irrigation

With the dry winter we have been having, it may become necessary to apply supplemental irrigation prior to bloom. It is important for trees to have adequate moisture in the root zone to support initial root and shoot growth. Roots begin to grow a few weeks earlier than shoots, and winter irrigation should be applied in time to support this early root growth. Late January and early February may be ideal times for applying supplemental irrigation if rains do not occur.

1998-99 Chilling Hours Update

Since there is some debate as to when chilling accumulation should begin, I have given several figures for each area. I personally am most comfortable with beginning chilling in mid-November rather than November 1. This is because trees are often not fully dormant in our area until after the beginning of November.

Much evidence exists that indicates that chilling in December and January is much more critical than that accumulated at any other time. UC Davis records going back more than 60 years indicate that there has never been a year with poor tree response to chilling in which at least 400 hours was accumulated in BOTH December and January. However, there have been many years in which 1200 or more total hours were accumulated, but trees responded as if they had suffered a lack of chill. In each of these instances the 400 hour total for either December or January was not achieved. This should help give an indication as to the importance of the quality of chilling - not just the duration.

California Treefruit Growers to Vote on Marketing Orders

The U.S. Department of Agriculture has announced that California nectarine, pear, and peach growers will vote January 5-29, 1999, on whether to continue their federal marketing orders.

Dr. Enrique E. Figueroa, administrator of USDA's Agricultural Marketing Service, said, "The orders require that continuance referenda be held every four years. To be eligible to vote, growers must have produced nectarines, pears, and peaches in California from April 1 through November 30."

For the orders to continue, at least two-thirds of the growers voting in each referenda, or growers representing at least two-thirds of the volume of these fruits, respectively, must vote in favor of the orders, Figueroa said.

Notice of the referenda is published in the Nov. 23 Federal Register. AMS will mail ballots and voting instructions to all growers of record. Eligible growers not receiving ballots may request them from Kurt J. Kimmel or Terry Vawter, USDA, AMS, 2202 Monterey Street, Suite 102B, Fresno, CA 93721; tel (559) 487-5901, fax (559) 487-5906.

This program will cover useful information to reduce arrival condition problems for stone fruit and cherry packers and shippers. Cold storage owners; sales people; packingline; hydrocooler, cold storage, truck, and container loading supervisors and operators are encouraged to attend. Demonstrations on packingline wax application; packingline bruising reduction; truck and marine container loading; chlorine, oxygen reduction potential (ORP), and temperature measurements will be done. A detailed decay identification laboratory will be conducted.

Lunch is provided by CTFA.

Reservations are required!! Reservations must be received by January 26, 1999. Walk-ins will not get lunch!!