Dormant sprays were applied on January 23, 2001.

Reduced input: Six gallons of oil in 200 gallons of water per acre.

Conventional: Six gallons of oil plus five pints of Diazinon® in 200 gallons of water per acre.

All blocks, both conventional and reduced input, have been divided into dormant spray and no dormant spray.

The orchard was monitored for overwintering San Jose Scale on January 18, 2001. Twenty spurs were gathered from each block, concentrating on the susceptible varieties Padre, Sonora and Butte. The spurs were examined under a microscope. The percent of twigs infested with San Jose Scale was calculated (table 1.).

Table 1.

Based on the fact that much of the orchard had over 10% infestation, current plans are to apply a May spray, 200 DD after the first emergence of SJS crawlers. Crawler tapes were placed on April 4, 2001 and are being monitored on a weekly basis. Samples gathered on April 26 were just beginning to show crawler emergence. The conventional/dormant spray blocks will be treated with Lorsban® at a rate of four pints in 100 gallons of water. The conventional/no dormant spray blocks will be treated with Esteem® at a rate of 14 to 17 ounces in 200 gallons of water per acre. The reduced input/dormant spray blocks will be treated with two gallons of oil in 100 gallons of water. The reduced input/no dormant spray will not receive a may spray.

Biofix for San Jose Scale was set at March 21, 2001. We are currently at 402 DD.

The orchard was evaluated for mummies on February 7, 2001. At this time, it was reported to us that the orchard had been mechanically shook for mummy removal. Forty- five trees, representing three varieties, were counted in each block. In most cases, the trees met the university recommendation of less than two mummies per tree. However, block two, both the conventional and reduced input treatments, had significantly more mummies than the rest of the orchard. Because we had monitored for mummies, we were able to alert the grower that an area of the orchard had been missed. Subsequently, crews were sent back to remove mummies from this area.

Monitoring the soil for overwintering female mites began on January 18, 2001. Each time, samples are taken from the same five trees in the block. Soil was brought back to the lab, put in a cup and the cup is placed on a sticky card. After two weeks, the females emerged from the soil and were on the sticky card. The number of females on each card were counted (figure 1). Block 1, of the conventional blocks, routinely had more mites giving the impression there might be significant difference between treatments. However, this was not the case. Leaf monitoring for mites began on April 11, 2001. Four trees were selected at random from the north and south ends of the plot one week and along the middle avenue the next week. Fifteen leaves were gathered from each tree. To date, we have only gathered interior leaves. However, beginning in May, half of the leaves will be selected from the interior of the tree and half from the exterior. The leaves will be brought back to the lab and examined under a microscope. The presence/absence method of counting will be used, indicating the number of leaves out of fifteen where web spinning mites are seen. As of this date, mites are just beginning to appear.

Figure 1.

Peach Twig Borer emergence was monitored in a second leaf almond orchard about two miles from the test orchard (figure 2.) Twenty hibernacula were gathered every five days. Peach twig bore traps were placed in the test orchard on March 28, 2001. The first male moths were observed on April 11, 2001. We are currently at 230° DD

Figure 2.

Based on emergence, two materials have been applied for the control of Peach Twig Borer. Confirm®, an insect growth regulator, was applied to the soft shell reduced input blocks, and Dipel®, a Bacillus thuringiensis product, was applied to the soft shell conventional input blocks.

During the 2000 season, a trial evaluating Lipinox® and Dipel® was conducted in this orchard. There were four treatments replicated five times. Each plot contained 37 trees. The trial was established in a reduced input block. Treatments and dates of application are shown in table 2. Timings were set to coincide with 40% and 80% peach twig borer emergence. All treatments were applied with a sprayer traveling at a ground speed of two miles per hour with pressure of 200 psi. Trees were evaluated for peach twig borer strikes on May 25, 2000. At this time there was no significant difference between treatments. All treatments averaged between 2.2 and 3.0 strikes per tree. At the time of harvest, a 200-nut sample was gathered from each plot in each treatment. Samples were brought back to the lab and evaluated for pest damage. The results are presented in table 3.

Table 2.

Table 3.

Navel orangeworm traps were placed on April 4, 2001

Pressure bomb readings began on April 25, 2001

The 2000 growing season saw shell seal problems, not only in this orchard, but throughout the county. This site had 70% open suture. Two other locations, at the south end of the valley, had 40% and 49% open suture.