Peach Twig Borer Control in Almonds - 1998

Seven different materials were evaluated for the control of peach twig borer, Anarsia lineatella, on 2nd leaf Nonpareil ctv. almonds in Arbuckle California. All treatments were applied by handgun sprayer delivering about 30 gpa as a dilute spray to runoff on nonbearing trees. Asana® + Oil and Success® + Oil were applied delayed dormant 1/21/98, all other treatments were applied during bloom as either a single application; Esteem® 2.9 Ec @ 4 & 5 oz/Ac + oil, two applications; Esteem® @ 4oz/Ac +oil, Confirm® @ 32oz/Ac, Comply 40w @ 4oz/Ac, Crymax® @ 1lb/Ac and Dipel DF® a@ 1lb/Ac or three applications Dipel Df® @ 1lb/Ac.

Single bloom sprays (B1) were applied, 3/10/98, at 20% larvae emergence, the two spray regime (B2) was applied 3/10/98, and again 3/20/98,at 80% emergence, the three spray program (B3) was applied 3/10, 3/20, and 3/30/98, at 100% emergence. Oil was applied as Volck® Supreme at 1gal/100gallons of water in the dormant or at 1qt/100gallons with Esteem® during bloom.

Two locations, Nickels Soils Lab & Charter Oaks, were treated with this protocol, however, data (table 1) was obtained only from the Charter orchard.

All treatments tested showed at least some level of control of the overwintering generation of peach twig borer in this test. Analysis of the data show equal control resulted from single dormant treatments of Asana® or Success® and from two bloom sprays of Crymax®, Dipel DF® and Confirm®. Equivalent control was also obtained with three applications of Dipel DF® throughout bloom (see Table)

Comply 40W applied as two bloom applications afforded good control also but at a somewhat lower level. The performance of Esteem® in this test is only fair in controlling PTB. This analysis is complicated by the addition of oil (which at a 1% solution is toxic to small PTB larvae) in the Esteem® treatment series. Oil applied in this test at a concentration of 0.25% could have been responsible for some mortality of PTB larvae in the Esteem®/oil plots.

Live twig borer larvae were easily found in the shoot tips of all Esteem® treatments and the untreated check trees, while no live larvae were found in trees sprayed with the other materials. No phytotoxic response was observed from any of the treatments.

Peach Twig Borer - Almonds
Handgun Application
Arbuckle, CA

# shoot strikes/tree

D= Dormant 1-21-98 Fishers P=0.05

B1= 1 application 20% larval emergence 3/10 /98

B2= 2 applications B1+ 80% emergence 3/20 /98

B3= 3 applications B2 + 7 days 3/30/98

Applied handgun dilute to 2nd leaf Nonpareil almonds, approximately 30 gallons of spray solution applied per acre.

Oil (Volck Supreme) applied at 1 gal/100 gal as dormant and 1qt/100gal during bloom

Rated 4/14/98 as number of PTB shoot strikes per single tree replicate.

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Copyright © 1999 Colusa County Cooperative Extension, Univ. of California
Last modified: September 01, 2000